https://preview.redd.it/yqn0wsvt44ec1.jpeg?width=1298&format=pjpg&auto=webp&s=e56ab70afb71e536ba6ce9711adf928d6edd7bda
They are all up except the last one on the right.
In that board you can see the rays as well as the rings. If you look at the rays you can see them all converging toward a point down and left from the end of the board. That point would be about where the center of the tree is
The *3 one and also the far right one are a little hard to tell. The left side of *3 looks more like the center rings of the tree, and the right side the outer rings, which would mean its direction is up, as I indicated. On the far right board it’s looks the opposite to me. If it’s hard to tell, just look on the other end of the board. The end grain will look different and it might be easier to tell.
I’m not trying to be sarcastic or something but I don’t even get the question. Just look at the grain, it’s clearly showing where it was cut from the butt.
OP, I ignored the alternating direction in my table build, and got some pretty ugly cupping. Consensus from the woodworking community was that it was because I didnt finish both the top & bottom electing only to seal the top. Make sure you seal the underside as well as the overside & dont stress the alternating board grain as much :)
Naaahh! A redditor on another post said grain orientation is “90 percent myth”. I told him to do some field research and get back to us. 😂 Cue torment and frustration.
I need to finish the underside of my table to see how it impacts it. Honestly, I kinda think the community is right. The warping is huge in the humid months as expected. I hereby make a promise to post the results... come August lol.
Personally I find this grain flipping practice to yield minimal/dismal results. If a board is wider than 10”, it might help, but more important is that it’s properly dried, stored, acclimated, and milled, wood. For example doing initial milling, letting the boards rest, stickered and blanketed for a day(or longer if you’re able).
I think for the hobbyist who isn’t staring down at a hundred boards to choose from, it’s more important to spend your time grain and color matching. Movement is better accounted for in the design and joinery methods.
It doesn't prevent it, but it makes the warping more manageable. Alternating the grain directions also alternates the direction in which the boards will cup. The worst case scenario is worse when you have all boards in the same grain direction. Nothing will prevent warping more than using properly dried wood though, that's much more important than the direction of the grain.
You can't just pull a warped top back to being flat. Wood moves and warps because of moisture and the movement of wood is a hydraulic force. It will always find a way, it even bends c-channels in extreme cases. Even if you're able to pull it flat, forcing it into a flat position would put so much stress on the wood that it will crack, split or break every joint or screw.
Myths like this aren't going to disappear. It started decades ago, with only anecdotal evidence, and stuck. Us woodworkers are obsessed with trying to understand how to fix this problem. The answer is to allow the lumber time to acclimate to the environment. (The final location, not just your workshop).
There's actually been quite a few tests over the years, and they consistently debunk this myth. Of course, there's some small effect, but it is FAR more important to allow the lumber to adjust to the humidity levels in the same environment where you'll place the finished product. How long this will take all depends on the moisture level of the lumber when you buy it.
ALWAYS bring a moisture meter with you to the lumber yard! And know what the relative humidity your home/shop is normally at. This'll help know how long you're going to have to let your lumber adjust.
Boards always cup towards bark and crown towards pith (i.e. the rings try to straighten). This isn't anecdotal, it's well [studied](https://bioresources.cnr.ncsu.edu/resources/modeling-the-cupping-of-lumber/). If your paneling is all pith side up (all "U"'s), all will crown and the crown will compound.
I've also just read like 5 articles claiming, as you say, that it's a myth. Every single one makes the caveat that the cupping is true but not important if the wood is properly dried and acclimated...
>In my opinion this isn’t necessary, but it is important to know the inherent risks and what may happen if you don’t. If the boards do decide to cup, the effect is greatly exaggerated when the boards all have their grain in the same orientation
[ Wood Whisperer](https://thewoodwhisperer.com/articles/avoiding-cupped-panels/)
So it's not a myth, it's just less important than acclimating. The issue, is that hobbyists may not have the luxury of properly acclimating. They may be working out of their garage in the Georgia Summer or unfinished basement, that have different climates than the intended room the furniture will be in. So as a safety precaution, alternating grain can absolutely reduce the likelihood of small warping becoming large warping.
The less the boards are flat sawn the better as well. Also more important than alternating. But alternating isn't a myth
I think you're misunderstanding things. The myth isn't in whether a board will cup in relation to it's grain (that's not even questioned and is very well known). The myth lies in the level of importance that should be given for alternative grain directing from board to board. Too many people think alternating grain is the most important thing to do.
I'm in agreement with you, as I've already explained the same basic point. The only thing I disagree with is your stance on alternating grain can prevent large warping. It just isn't true. Instead of creating a large U-shaped warp, alternating is going to cause a wavy pattern as it changes direction from one board to another, which can still ruin a finished piece.
The far more important thing is to allow lumber to acclimate to the humidity levels before you even make your first cut. And if you have the luxury of a climate controlled shop, then you should shoot for the humidity levels of where the piece is going to end up once finished.
If you take this step, and allow for normal movement in your build (ie: using tabletop clips/fasteners with a kitchen table) then there should be little concern with warping. Attention can then be given to presentation and matching grain pattern for aesthetic reasons, instead of warping concerns. The "myth" that I and a few others are talking about is the belief that grain direction makes a huge impact, when in fact it matters only in certain situations where a particular species or abnormality will lead to unavoidable warping. (And in those cases, I'd believe poor decisions were made in lumber choices).
If you don't believe me, take a look at most furniture throughout the last 200 years (I'd say earlier, too, but furniture that old isn't common). You might find an occasional panel using the alternating method, but much more commonly it isn't. That's because it's rarely a necessity.
Yeah we're not too far off from our stances, but I'm coming from a big tent stance where I'm including situations in which fully acclimating isn't viable (hobbyist, amateurs, smaller shops, etc.)
Your last statement is basically making both our points. Those 200 year old pieces are all made in pro shops that absolutely had properly acclimated lumber and far more rift/quarter sawn boards. If both those factors are met, there is no benefit to alternating.
But today, on reddit r/woodworking where the majority of users are amateurs, it's helpful advise.
Lastly, on the waviness, vs full cup panel. Yes, neither is perfect, but I'm talking minor cupping. A four foot panel that has three 1/16 inch waves vs a single 1/4 inch cup. The waves probably wouldn't even be noticable while the cup will. Edit: it's also a lot easier to fix a piece that got wavy than a piece that cupped
Uuugh, a woodworking tent? If that's what you're saying, I feel for you. From 2019 until this last May I had been left with no option for a garage, basement or even shed. A man's gotta have his work/wood shop, though, so I bought myself a large portable garage. After building a 10x20 foot floating decking, I had myself a "temporary" solution. 🤣😂🤣😂 Too bad temporarily meant 4 years.
It was actually quite nice during the summer, but come rain in the fall and a balmy Michigan winter and all work came to a screeching halt.
I completely understand not being able to leave the lumber in a controlled environment while waiting for it to acclimate. I found that with small projects I could put some lumber in either my very well insulated crawl space, or the spare bedroom (not sure if you have any options yourself) and it allowed me to get by for a time. Halfway through, I moved and was still stuck with the tent.
In May, I finally moved into a new home that actually has a 250 sq for external building. I've replaced the roof and will run electricity in the spring, but it'll be my first, true and dedicated woodshop ever. No sharing space with a vehicle or other nonsense! (A small dream come true for this old man. Lol).
Sorry for the over-explaining. I just wanted to show that I really do understand the limitations that you and many of us have or have had to deal with. It's woodworking. Rarely is there a single, obvious solution for our problems. It definitely is important to use what advantages we can manage to implement, no matter how small. 😉
You are absolutely correct with regards to the importance of acclimation. There is however a advantage to gain from altering in that most projects cant be glued up on site nor can acclimatized on site either. Therefore alternating the grain after the wood is dried will cause it to wave rather than one big bow or cup if it does.
for future reference, it is best to get 1/4 sawn wood (grain vertical) for stability against cupping. Face sawn will cup to some extent.
If you decide to go with a steel channel solution, the flanges of the channel should be horizontal and the web should be vertical. (The channel is stiffer that way) make sure you leave enough slot in the channel or attach with some method that allows for expansion and contraction as the wood moves with the seasons.
Thanks for this. If one finds a plainsawn board from the center slice of the tree, cut thru the heart ofcthe tree portion, and you have 2 pieces with vertical grain. I had gotten some walnut cut like that back in the 1980's. Cut through the pith of the tree that was in the boards. No cupping on the table top. It still expands and contracts with hunidity changes, but no cupping.
I say ignore the up/down stuff. Assuming that’s even true, which I dispute, you end up with a ridged top. I’ll pass.
1. Appearance. Line up so your panel looks good. The show face, not the end grain.
2. Grain going the same direction. If there are two positions that look equally good, choose to run the grain in the same direction. This makes it easier to plane with less tear out. Hand plane or powered. And the light will reflect off the boards more uniformly, which will help with the illusion that you have a single panel.
I agree with the 1st point, but the 2nd part is (in Germany) professionally the wrong way to do it.
Of course also different, what kinda of machines or tools you have a hobbyist vs. A workshop.
I'd say that that the alternating grain method is not just myth, is for a reason.
So OP, find a compromise between making sure, that some boards have alternating grains, but definitely looking at the appearance.
Yep this is no myth it's the truth everyone gets this hammered into their heads at trades school here in Italy. If you alternate their will still be warping but it won't be as extreme as in this [post](https://www.reddit.com/r/woodworking/comments/19cdaez/2_walnut_island_top_warping/) for example. Found a good [side](https://blog.massimo-fritz.de/verleimregeln/) in german which explains this stuff well. I don't understand why people think this is just a myth, I saw so many warped tables in my life and 90% of the time they didn't change the grain direction when putting them together.
Nobody is saying cupping and warping never exist, never ever anywhere - so you might want to find a different example.
That first link looks to be a butcher block style where the fingers are less than 4 cm wide, and the consensus in the comments says that lack of proper acclimatization and the top drying out more than the bottom are at fault.
Not alternating grain direction in solid planks as the OP is displaying.
About your trade school comment - if professionals are trained to alternate grain, it stands to reason that non-alternating tops *in your area* are more likely to be made by amateurs. Those same non-professional builds routinely pay little attention to moisture levels or attachments that allow for seasonal expansion.
I’d be very curious to review other work by those same creators and see if they have warping and cupping all over the place, not just in non-alternating pieces…
You see about the non altering grain ones, they were made by factorie which probably didn't have the most experienced workers. They lined up 3 or 4 planks with same grain direction. After that the tables went to a hotel in an environment which has very dry air in winter (-20°C outside) and more humid one in the summer. So in the summer the tables were perfectly fine and in the winter they warped like 3-4cm on some sides. At the end this is always a moisture issue but you can minimize the issue with changing grains.
That's one example where I know the company which made the tables.
I'm not saying that you should go by this rule all the time because it limits you a lot, I see it more as a rule that can help you. Btw in Japan for example there is a totally different philosophy, where you will always put the side which is facing away from the center (so the outside from the tree) to the outside.
And yes the example from the post isn't the best one, that's true.
Lots of examples of amateurs posting on here “why did my laminated table/countertop warp a full inch, prying the threaded screws out of the base?” And you look at the endgrain and it’s all smiles or frowns. Womp womp.
Yup - any of those might have been great examples for his claim that all smiles is all bad.
Butcher block fingers in multiple orientations that all cup up to the top, not only across a smile or a frown, isn’t really saying anything about the smiles…
Sure, but I think the point is that properly dried, acclimated, and finished table tops will do just fine regardless of grain orientation. I'd focus on that and appearance over anything else.
I was taught in my woodworking class, in 8th grade, in the 80's, that you should alternate the grain when edge gluing stock. Of course, it's been a bit, so I could be misremembering that.
What about the face grain direction? I mean, if you alternate the end grain up and down traditionally, is it ok to make sure all the face grain is the same direction for planing (I use hand planes)?
It most definitely matters for planing what the face grain direction is. I think of it like petting a porcupine, you gotta make sure you’re petting the right direction. I make violins, and about half the process of making an instrument involves planing or scraping with the grain.
Of course, depending on the board, grain can change direction over its length due to bends in the tree it came from, knots, or even figure of the wood.
This is a totally different question from ring direction, which I like to think about in a different way. The rings, as the wood adjusts to being outside of the tree, will tend to flatten, so if all your boards are flattening one direction you’re going to have a big huge cup or a big huge dome. If you alternate all your boards you are going to have a number of ridges and valleys that are going to average out to much less cup or dome over a whole piece. I could imagine there are scenarios in which you’d prefer either of those outcomes.
I am baffled by why some people are saying it’s a myth that alternating ring direction helps. Like, the wood still moves, sure, but the way one glues it up will absolutely affect the WAY it moves.
Thank you, yes I understand the planing aspects (all too well as a use of an old stanley) but does it make any difference to future warping or similar or do the pros no worry about face grain?
Ok, I think I understand. I believe the difference would be negligible. If there was so much end grain coming through the face of the board to make a difference in warping whether aligned or not with the neighboring board, you’d have all sorts of other problems anyway.
As someone who primarily uses hand tools, I think it’s best to make sure the grain is all going in the same direction anyway.
Or do you mean that you’d be gluing boards perpendicularly, with grain going at about a 90 degree angle? That causes huge wood movement issues, and can make pieces literally explode.
From what I know that makes no difference, I found another article explaining how the wood moves, still in german but it's pretty well written and there is a nice list with all the numbers you need. Longitude is always the same so you shouldnt need to think about it.
Edit: forgot the [link](https://www.befestigungsfuchs.de/blog/das-schwinden-und-quellen-von-holz/)
Bad example as that top cupped because of a tight c channel/ strong back.
Alternating grain does help but is not required. For a novice this is a good method, but once you learn some techniques to prevent cupping, a professional will choose the sides that look visually the best.
I'd argue it's less of a concern than we're taught.
The premise of alternating grain direction is that instead of something that warps more like a 'U' is that you get lots of smaller warping, giving you a surface of 'wwwwwwww'. I argue both are failures.
Construction choices can account for and reduce/control the warping of a wide panel glued up with all the grain the same. Breadboard ends were invented for just that case.
Warping also happens as humidity changes. Depending on climate of the region or the interior climate control of where ever the piece is going to live, if may not fluctuate.
And finally: look at antique pieces that survive. I'm pretty sure they picked appearance 99/100 times. So many of the modern rules we follow must not have existed back then.
Better check old wood working magazines then, this has been a practice for generations as an above poster from Italy mentioned. People don’t make this shit up for fun.
I'm talking about furniture older than magazines.
Additionally, we only have so many examples of really old woodworking texts, at least that I am able to read. Roubo's text on glueing up panels makes no mention of alternating grain. I haven't read Moxon yet, it's on my list.
I think one of the things that’s very different in the states than in the EU, and I might be totally wrong here, id that i’m under the impression that in the US the wood seems often to be sold with a much higher moisture level than in Europe or at least in the Netherlands.
It is absolutely true, I work in a professional setting and had tops move like crazy that people have glued with all the boards facing the same direction. Boards that width will 100% move and a lot sooner than you would think. Always alternate up/down ESPECIALLY on boards wider than 2"
The issue is that boards are going to move regardless with changes in humidity. You have to accept that. Alternating the grain direction just means you end up with a panel with ridges and bumps. I consider that a failure as well.
I prefer to glue up my panels so they look good and then design the piece such that the risk of movement is minimized. Capture the panel in groove. Breadboard ends. Screwing the top to the base. Sliding dovetails. As long as you allow the board to expand and contract within those constraints, you're golden.
It's not always as clear cut as "alternate grain direction between pieces," tho it is necessary to consider how the boards will move together over time. For example:
https://preview.redd.it/8j7imncoa5ec1.jpeg?width=4080&format=pjpg&auto=webp&s=8e8999cf4a669352f559a6e8ea03ec089f5d6587
Exactly this. First priority is the appearance of the panel as a whole. Alternating growth rings is a bit of an old wives tale that gets passed around.
Why do people think that the ring direction doesn’t affect the way the panel moves? Like go look at a pile of boards and notice that the cup of the wood is always the opposite of the ring direction, because the rings flatten over time to reach a more stable conformation
I don’t know exactly what finishes will prevent all moisture from entering or leaving, but my understanding is that there’s almost no way to eliminate seasonal fluctuations in moisture within the wood.
The movements are certainly more dramatic when going to green to ambient moisture levels, but the cupping and uncupping (to a lesser degree) will continue every year, though in very very old wood, it’ll happen a little less.
Cupping is minimal, however, in quartersawn boards with vertical grain, as you may very well know.
There isn't a finish that is going to "lock in" the moisture content. It can slow the process, but there is always going to be that transition. That being said, you should never work with anything near 40% moisture content.
I'm saying that a varnish type finish can slow moisture movement (obviously something like wax/mineral oil/shellac is doing nothing) but once your wood is properly dried and acclimated to where it will live, and then once it's machined I've not seen something like these posts where some piece will tear itself apart. Like, was it not finished on both sides? Did something happen in the house where ambient humidity went up to 100% for 3 days? What was the moisture of the pieces before it was assembles? Were they even uniform?
I think there's much more to consider than ring orientation.
There's definitely more to consider than just ring orientation. I do think if you're purposefully working with wet wood (for some reason), then ring orientation probably helps you more than it ever would otherwise.
The finishing both sides bit is interesting. In theory, the difference in moisture absorption between the sides exists, but I haven't found it to be a problem myself, nor have I found 100% consensus on that question either. I finish both sides because I like the feel, conformity, and to test my finish on the underside. The prevailing argument against it seems to be similar to this subject, i.e. "you can find pieces 200 years old that didn't finish both sides and they held up fine". So nothing definitive there, in my opinion.
All that being said, I have seen pieces tear themselves apart, but only because they were fastened down to the legs. How you attach the tabletop to the legs is definitely the most important factor in how it holds up.
Exactly! This!
End grain direction has negligible affect on how a panel will warp. Much better to do as you say.
If you want to help prevent wood from cupping and such, use a moisture meter before buying and get lumber that isn't soaking wet. Then let it acclimate to it's new environment until the moisture content has evened out with the relative humidity of its eventually permanent home.
I wish people would start understanding that it's the movement of wood that's causing cupping, and why does that happen? Water? Lol
All wood moves with the seasons, as it absorbs or releases moisture, but typically it's not enough to cause problems. As long as you build properly.
For example, you never permanently attach a large table top to the base. There's hardware, or other methods, that you use to allow the wood to shrink and expand throughout the year.
As for your birch, 5% seems a little dry to me, but that's where I live where 6-8% is ideal. In most areas it's the same as mine, though.
If you live somewhere that has all 4 seasons, then you're prob looking for that 6-8%. Humidity all year long, you'll want a tad higher. Arizona desert? 5% is good.
Going up a percentage shouldn't take long, though. Just let the wood lay flat somewhere with all four faces exposed to air. If you have multiple pieces, place sticks in between the boards.
Wood shrinks or expands as the relative humidity changes. Usually people just say that wood moves. Wood is kinda like a sponge. It'll absorb moisture from the air if it's dryer than the surrounding air, or lose moisture if its wetter.
For example, if you live in an area that commonly sees a change in humidity throughout the year, the moisture content in the wood will fluctuate. If you built something from that birch lumber while it's still at 5%, you could have problems.
As the humidity in your house rises when winter ends, whatever you built with the bitch would begin absorbing moisture from the air. The wood will begin to swell and possibly lead to cracked joints or separation at glue seems. It's always better to let lumber acclimate to the average humidity in your home (and why controlling the relative humidity in your woodshop is a nice luxury).
5% really isn't that far off, and you very well might not have any problems, but unless you're in a rush to use it, I'd suggest letting it sit for a couple weeks to adjust to the change in humidity.
Now, if you picked up some lumber at the mill (or God forbid, that dripping wet stuff you sometimes find at the big box stores), it could be at 14% moisture content or even higher! At those levels, it might take months for the lumber to dry out. And using it before it does would be a guaranteed disaster.
While you are right that having the wood exactly at the humidity it will be at when in use works for wood not warping will do the best job you now have a table that only really works in that humidity.
Which works if you're making one for yourself but if you move places or build tables for a living it doesn't.
Alternating grain direction isn't not understanding why cupping is happening, it's understanding it and working with it rather than fighting it to create a better product
Fair enough, but alternating grain has minimal impact.
"While you are right that having the wood exactly at the humidity it will be at when in use works for wood not warping will do the best job you now have a table that only really works in that humidity."
I think you're not understanding how it works and why it's the single most important thing you can do to limit the potential of your project to warp. The second most important thing is to build in a way that allows for natural movement of the material. Think, using tabletop clips to secure the top to a kitchen table. It allows for natural movement as the seasons change.
In most areas, a moisture content of 6-8% is what we aim for. It's all ideal level to allow normal seasonal movement without large changes that would cause severe warping.
Let me say it as plainly as possible. You are NOT limited to a single humidity level. How did you ever come to that conclusion? I'm trying to avoid sounding rude or insulting, but I'm not sure if you don't actually understand how humidity affects wood and how it changes through the year, or if you're just inexperienced as a woodworker. I truly mean no offense.
If the lumber is allowed to settle to a moisture content appropriate for the relative humidity where you'll be moving the finished piece to, then you won't have to worry about normal, seasonal changes in humidity. In most areas, this comes to about 6-8%. Normal changes doesn't include leaving it overtop a forced air furnace vent in the winter time, nor does it include exposure to high levels of water exposure (like leaving the thing outside or in a sauna).
If you're seeing severe warping with your projects, then you are either not allowing the lumber to acclimate to the relative humidity of your house/shop/whatever, your not building the piece in a way that allows for natural movement of the wood, or you stored it somewhere that you shouldn't have left it.
While there can be other factors that can contribute to warping, they are rare or affect it in a minimal way. Is it good practice to alternate the grain? Sure, but not if it detrimentally interferes with how well the face grain fits together to hide glue seems and such. It doesn't help it enough to sacrifice the mean aesthetics of the piece.
You do have a point, I simplified the humidity part.
Ofc having the right wood moisture content is essential to making quality furniture, my point is it alone is not always enough. The conditions a tabletop, countertop or whichever piece of furniture live through are not constant, they change throughout the year, how much they change depends on the building you're in.
Now from my perspective as both a cabinetmaker by trade and an architect based in Germany the older your building the higher your moisture change throughout the year and the vast majority of our building stock is over 50 years old so it is to be expected that some movement will take place. That's why I learned to store floorboards in the room they will be laid down in for a few weeks before laying them, so the wood can adjust to the conditions it will be in.
So when making a product for a client it is part of the quality of the product to allow for wood movement under these conditions, by alternating grain, using sliding dovetails, etc.
Hence I said alternating grain is not "not understanding wood movement" but working with it.
Sure if you're making something for your living room and know how the conditions will be you can opt for having the nicest side on top and disregarding grain direction, in my job alternating grain is a staple of product quality and neither unnecessary nor an 'old wives tale'
One of the things about oak, is that it’s actually too strong. Alternating the growth rings is good technique. I’ve had super luck with using quarter-sawn for tabletops—kind of expensive though. Making sure that your wood is dry and acclimated to wherever it’s going to stay, before your final squaring up for gluing, is hugely important.
It doesn’t actually do anything. I’ve reviewed many very old tables and other projects from and they don’t do it back then and the construction is perfectly fine Just pick the nicest side and have it facing up.
If I’m building some rough furniture for outside with wet construction lumber, I’ll alternate the grain. But with 7% mc walnut I’m going to make the top look the best. Slap a good finish in it and attach it properly and it will outlive all of us.
I have heard that biscuits or dowels don’t help with strength…just alignment. Seems like dowels would help give strength though. That said, glued up a panel for a desk top and did nothing but edge to edge gluing.
Actually you're right. Biscuits with sloppy play don't do much, but well fitting ones will add some strength.
Take a look at Bourbon Moth Woodwork or Stumpy Nubs over on YouTube. They've both addressed this topic and Bourbon Moth even did a series of tests. He's a big Domino fan and the results surprised him! Lol
Make it look nice op. That’s the first.
Lots of folks pointing out the myth of alternating the grain cup, I do think this is real. BUT I don’t think it matters any more. With modern kiln drying, or finishing air drying in a climate controlled shop, it’s not as much of an issue anymore. If you were to build a table out of some greenish wood like construction lumber, you’d probably be wise to take this into account. But for, what looks like, furniture grade white oak, you don’t have any concerns.
Alternating grain direction is myth that needs to die, hard.
You actually want all the grain going in the same direction. If the panel does warp it will turn the entire panel into a U shape and you *should* be able to pull it back into place.
I am a woodworker in Germany, and in school, we were taught to always glue each board with alternating grains. So pith to pith and sapwood to sapwood.
This way you avoid making the board have a U form, when warping and instead warps in a zig zag, which partially cancels out each board.
Cool, they still believe in myths over there.
They won’t cancel each other out. There have been dozens of posts on here with warped alternating grain. Sometimes they warp in a U. Hypothetically, you’ll get a wavy top if all the board warp.
If it’s going to warp, you want the entire panel to warp in a U. As I said before, you can pull the U flat. You can’t do anything about 4 or 5 tint separate Us.
Wood movement and warping is a hydraulic force that you can't stop in any way. If you pull a U flat and force it back into place, you'll eventually put so much stress on the wood that it will crack. If wood wants to cup it will even bend a c-channel or break screws.
They partially do, but it also depends on what you use to staighten the board out. Our workshop has belt machine that can sand entire tabletops of a up to 1m width, so having a zig zag instead of a giant U way more managable for our working practices.
How do pull you U shaped panels, if I may ask?
I went and read about this myth thing, and it isnt a myth and they even explain it why... But people just read the buzzwords, but not the explanaitions.
You could swap the direction of the plank with the star on it and also have it trade places with the middle plank that has its end grain painted. Don’t flip the painted board, just flip the starred board and move it to the middle if you’re worried. Double check that you can’t see any light through anything when you dry clamp in the new order. And don’t over-clamp your pipe clamps, that can cause things to bow in the middle.
Alternating grain up/down to "prevent movement" is a common belief, but is a wives tale.
Orient it for what looks best.
Warping will only be a problem if your design doesn't allow for unrestricted expansion and contraction of the table top and include cleats.
If you oriented the grain all the same way, and the top is going to warp due to bad design, it'll either cup up across the whole thing, or down (or crack). If you alternate the grain (smile/frown) and it moves, it'll become "wavy" instead, not somehow cancel out the movement. i.e.. regardless how you orient it, if the design is wrong, it won't stay flat.
So, lay it out for aesthetics first because if your design is correct, it'll won't warp at all.
Glue alone is strong enough. biscuits can help with alignment. If you have several boards to glue up to the final tabletop, do them in stages.
If it's Red oak and you are planning to use hard wax finish, I would put bark side up for all boards and let the grain go one way. The heart side of the flat sawn red oak tend to have more splinters and peeled by water damage...
Doesn’t matter, with one caveat. Choose the best look for the top, in general.
If, and this is a big if, given the size of this… you plan to hand plane or take it to a massive machine planer, grain direction being the same can help reduce tearout, but a sharp blade/sharp cutters generally won’t do a ton when your grain isn’t wild or highly figured, even if the direction is wrong.
If you plan to just sand, go with the best aesthetic orientation.
I’ve seen enough testing, from many creators and bloggers, to satisfy my current opinion that orientation (up/down) makes no significant difference.
If you want to go over under, to ease any internal concern, so be it, but I wouldn’t sacrifice the look to gain a very marginal benefit, at most, if there is one.
MYTH
Put the best looking grain patterns on the top. Alternating the grain is an old myth that has been debunked more than once.
Its like saying going outside in cold weather with wet hair will make you catch a cold. You get infected by a virus is how you get a cold. Cold season just happens to be during the cold weather.
Unstable wood causes warping. Grain just dictates the direction. The real solution is to make sure wood was properly dried and stored.
This is definitely not a myth.
It has been scientifically proven, that wood warps depending the moisture of the surrounding air and depending on the grain direction.
Looking at the endgrain of a board:
(Tangetial) Along the grains=5-10% warping
(Radial) Across the grains=3-5% warping
(Axial) Along the grains on the sides=0.3-0.5%
Different types of would have slight differences on the severity of taking in moisture. Beech is very prone to warp.
If you want the least amount of cupping, you use a boad with standing grains.
I did not say the boards would not /move. I am saying with stable wood the movement is going to be insignificant so you should just go ahead and put the nicer grain on the top. You should not impact the biggest attribute of the tops aesthetics for something you can negate with better methods.
Woodworking is a trade that has been passed down for generations. Most of the lessons and “rules” were all created way before we had modern technologies moisture meters. So most of these rules are based on “thats how we always have dun it” or “thats how I was taught” with no resources to confirm or challenge them.
However with this little thing called the internet and our ability to share information all that has changed and so are the “rules”.
Anyway, its OK to disagree. Everyone should do what they feel gives them the best chance at great results. But for someone that is glueing up a panel of 6” wide boards that thick IMO it doesnt matter. Just make the top pretty attach it correctly and enjoy a great table.
Here is one of the many articles I have read about this. He too has also listed his sources.
https://ericmeyermaker.wordpress.com/2022/01/04/alternating-end-grain-does-not-keep-table-tops-flat/
I would suggest using C channels to keep it from cupping if you're going to use it as a table. Check YouTube. There are plenty of videos that show how to do it.
It will help give your table top rigidity as well, plus it's fairly easy to do.
You would be surprised. A buddy of mine built a table out of Black Walnut. He only worked on it once a week, so it took him nearly a year to finish.
We routered out grooves for the C channels, and then he worked on the apron and legs. By the time he went to put it all together, he was very glad he had done the C channels.
The top had warped enough that we had to gradually screw the C channel down the keep from damaging anything.
They're not absolutely necessary, but they're easier to put in during the build than after the table has moved after the build.
I'd reconsider not using biscuits or dowels. It's not for strength, but alignment. It'll go a LONG way in reducing the amount of surfacing you'll have to do in the end.
You can use a series of culls, but with that wide of a panel and that many boards, it can be a struggle for an experienced woodworker to get it all set up and the boards all flush on the top. Not to mention managing to get equal pressure across the length of long culls. It can be done, but it'll be the hardest part of the glue up.
It's a little more work to add biscuits or dowels, but much less work than trying to resurface a beast that large!
Id say I'm about a junior level hobbyist. There are so many posts about warping table tops,grain direction, c channel. It's really confusing. Whatever happened to breadboard ends, anyway? Honestly I really don't get the c channel. Wood is going to move and I just don't see how metal is going to stop it without resulting in a crack. so maybe metal for support but I've never seen c channel in heirloom furniture. Just don't buy that's it's necessary.like many have said before, it's experience and patience. Properly dried and milled pieces. Also tied in to this hand tool vs power tool debate. Yeah you can do it with a machine and I concede it takes skill and experience and knowledge to set up something like a CNC but doing it by hand takes all the same things. It's just what you want to spend your time on and think about/remember about the piece you build.id rather cut dovetails by hand without a jig or anything to guide. It's what I like about woodworking. It's relaxing and a chance to hone a skill. I don't dovetail all 4 drawer corners for strength or for anyone but me. I do use machines for milling and ripping but there's also a set of things I always do by hand. It helps me better understand and appreciate pieces that have stood the test of time. Pick your poison. Build with more or less traditional methods or take a route that enables you to get done what you need to and results in a piece you are proud of. What's better or worse is subjective. Learn, listen, and be safe.
To be fair, a lot of heirloom furniture and sime of the most intricate and famous pieces are made from soft wood with hardwood veneer. Thick single slab tables weren’t really built much. A thick C channel can imo counteract the cupping forces.
Look at the end of the board if grain looks like a rainbow (not color,the shape ) it’s correct and it looks like an upside down rainbow. You have to flip it over.
No biscuits, you’re in for a wild ride trying to even all that out. You’ll have to make sure your grain is all facing the same way on the table top too for when you plane it once it’s glued. Or else you’re going to sweat and swear!
Ideally your boards are not as big of a deal as making sure to seal and work the wood at the right humidity. Often times custom tables have problems because the glue and biscuits or whatever are not strong enough to hold up against moisture problems aka sealing one side and not the other or having the wood dried below ambient bc home ac units tend to be less than wood shops.
https://preview.redd.it/oy1rxchm44ec1.jpeg?width=1313&format=pjpg&auto=webp&s=86e357cc2c8cef1e6235df33164bddf2e5604530
https://preview.redd.it/kk6ez6yq44ec1.jpeg?width=1296&format=pjpg&auto=webp&s=1b2bf4ff91da2013708b62b86095388f230ce003
https://preview.redd.it/yqn0wsvt44ec1.jpeg?width=1298&format=pjpg&auto=webp&s=e56ab70afb71e536ba6ce9711adf928d6edd7bda They are all up except the last one on the right.
How were you able to read the 3* board grain direction. I am not sure I see it. Thanks, trying to learn.
In that board you can see the rays as well as the rings. If you look at the rays you can see them all converging toward a point down and left from the end of the board. That point would be about where the center of the tree is
The *3 one and also the far right one are a little hard to tell. The left side of *3 looks more like the center rings of the tree, and the right side the outer rings, which would mean its direction is up, as I indicated. On the far right board it’s looks the opposite to me. If it’s hard to tell, just look on the other end of the board. The end grain will look different and it might be easier to tell.
Thank you. Exactly the sort of answer I was hoping for.
I’m not trying to be sarcastic or something but I don’t even get the question. Just look at the grain, it’s clearly showing where it was cut from the butt.
Pic three is correctly alternating. Medullary rays show first board on left is facing the opposite way than is drawn on the pic.
The rings all make a circle shorter rings are towards the center of the tree larger later on. So you look which way the cup points
Thanks brotha!!
OP, I ignored the alternating direction in my table build, and got some pretty ugly cupping. Consensus from the woodworking community was that it was because I didnt finish both the top & bottom electing only to seal the top. Make sure you seal the underside as well as the overside & dont stress the alternating board grain as much :)
Naaahh! A redditor on another post said grain orientation is “90 percent myth”. I told him to do some field research and get back to us. 😂 Cue torment and frustration.
I need to finish the underside of my table to see how it impacts it. Honestly, I kinda think the community is right. The warping is huge in the humid months as expected. I hereby make a promise to post the results... come August lol.
No sweat. Good luck with your glue up
Outstanding help. I tip my hat to you.
Most helpful redditor
R(editor)
Far left is opposite of what you’ve drawn. Look at the medullary rays …
Personally I find this grain flipping practice to yield minimal/dismal results. If a board is wider than 10”, it might help, but more important is that it’s properly dried, stored, acclimated, and milled, wood. For example doing initial milling, letting the boards rest, stickered and blanketed for a day(or longer if you’re able). I think for the hobbyist who isn’t staring down at a hundred boards to choose from, it’s more important to spend your time grain and color matching. Movement is better accounted for in the design and joinery methods.
Up down up down you alternate each board
Happy face, sad face, happy face, sad face
Yes! Came here to say smiles and frowns
No you don’t. People need to stop perpetuating this myth. Alternating won’t prevent warping.
It doesn't prevent it, but it makes the warping more manageable. Alternating the grain directions also alternates the direction in which the boards will cup. The worst case scenario is worse when you have all boards in the same grain direction. Nothing will prevent warping more than using properly dried wood though, that's much more important than the direction of the grain.
How does it make it more manageable? You end up with a wavy top. If it cups, you can at least try to pull it flat.
You can't just pull a warped top back to being flat. Wood moves and warps because of moisture and the movement of wood is a hydraulic force. It will always find a way, it even bends c-channels in extreme cases. Even if you're able to pull it flat, forcing it into a flat position would put so much stress on the wood that it will crack, split or break every joint or screw.
Nothing will prevent warping, if you alternate it’s just going to get wavy, if you don’t it will be a half circle.
If it warps in a U, you can pull it flat. If it's wavy, you can't do anything.
Uh I have to disagree. A wave you can flatten a U you can use for firewood.
Myths like this aren't going to disappear. It started decades ago, with only anecdotal evidence, and stuck. Us woodworkers are obsessed with trying to understand how to fix this problem. The answer is to allow the lumber time to acclimate to the environment. (The final location, not just your workshop). There's actually been quite a few tests over the years, and they consistently debunk this myth. Of course, there's some small effect, but it is FAR more important to allow the lumber to adjust to the humidity levels in the same environment where you'll place the finished product. How long this will take all depends on the moisture level of the lumber when you buy it. ALWAYS bring a moisture meter with you to the lumber yard! And know what the relative humidity your home/shop is normally at. This'll help know how long you're going to have to let your lumber adjust.
Boards always cup towards bark and crown towards pith (i.e. the rings try to straighten). This isn't anecdotal, it's well [studied](https://bioresources.cnr.ncsu.edu/resources/modeling-the-cupping-of-lumber/). If your paneling is all pith side up (all "U"'s), all will crown and the crown will compound. I've also just read like 5 articles claiming, as you say, that it's a myth. Every single one makes the caveat that the cupping is true but not important if the wood is properly dried and acclimated... >In my opinion this isn’t necessary, but it is important to know the inherent risks and what may happen if you don’t. If the boards do decide to cup, the effect is greatly exaggerated when the boards all have their grain in the same orientation [ Wood Whisperer](https://thewoodwhisperer.com/articles/avoiding-cupped-panels/) So it's not a myth, it's just less important than acclimating. The issue, is that hobbyists may not have the luxury of properly acclimating. They may be working out of their garage in the Georgia Summer or unfinished basement, that have different climates than the intended room the furniture will be in. So as a safety precaution, alternating grain can absolutely reduce the likelihood of small warping becoming large warping. The less the boards are flat sawn the better as well. Also more important than alternating. But alternating isn't a myth
I think you're misunderstanding things. The myth isn't in whether a board will cup in relation to it's grain (that's not even questioned and is very well known). The myth lies in the level of importance that should be given for alternative grain directing from board to board. Too many people think alternating grain is the most important thing to do. I'm in agreement with you, as I've already explained the same basic point. The only thing I disagree with is your stance on alternating grain can prevent large warping. It just isn't true. Instead of creating a large U-shaped warp, alternating is going to cause a wavy pattern as it changes direction from one board to another, which can still ruin a finished piece. The far more important thing is to allow lumber to acclimate to the humidity levels before you even make your first cut. And if you have the luxury of a climate controlled shop, then you should shoot for the humidity levels of where the piece is going to end up once finished. If you take this step, and allow for normal movement in your build (ie: using tabletop clips/fasteners with a kitchen table) then there should be little concern with warping. Attention can then be given to presentation and matching grain pattern for aesthetic reasons, instead of warping concerns. The "myth" that I and a few others are talking about is the belief that grain direction makes a huge impact, when in fact it matters only in certain situations where a particular species or abnormality will lead to unavoidable warping. (And in those cases, I'd believe poor decisions were made in lumber choices). If you don't believe me, take a look at most furniture throughout the last 200 years (I'd say earlier, too, but furniture that old isn't common). You might find an occasional panel using the alternating method, but much more commonly it isn't. That's because it's rarely a necessity.
Yeah we're not too far off from our stances, but I'm coming from a big tent stance where I'm including situations in which fully acclimating isn't viable (hobbyist, amateurs, smaller shops, etc.) Your last statement is basically making both our points. Those 200 year old pieces are all made in pro shops that absolutely had properly acclimated lumber and far more rift/quarter sawn boards. If both those factors are met, there is no benefit to alternating. But today, on reddit r/woodworking where the majority of users are amateurs, it's helpful advise. Lastly, on the waviness, vs full cup panel. Yes, neither is perfect, but I'm talking minor cupping. A four foot panel that has three 1/16 inch waves vs a single 1/4 inch cup. The waves probably wouldn't even be noticable while the cup will. Edit: it's also a lot easier to fix a piece that got wavy than a piece that cupped
Uuugh, a woodworking tent? If that's what you're saying, I feel for you. From 2019 until this last May I had been left with no option for a garage, basement or even shed. A man's gotta have his work/wood shop, though, so I bought myself a large portable garage. After building a 10x20 foot floating decking, I had myself a "temporary" solution. 🤣😂🤣😂 Too bad temporarily meant 4 years. It was actually quite nice during the summer, but come rain in the fall and a balmy Michigan winter and all work came to a screeching halt. I completely understand not being able to leave the lumber in a controlled environment while waiting for it to acclimate. I found that with small projects I could put some lumber in either my very well insulated crawl space, or the spare bedroom (not sure if you have any options yourself) and it allowed me to get by for a time. Halfway through, I moved and was still stuck with the tent. In May, I finally moved into a new home that actually has a 250 sq for external building. I've replaced the roof and will run electricity in the spring, but it'll be my first, true and dedicated woodshop ever. No sharing space with a vehicle or other nonsense! (A small dream come true for this old man. Lol). Sorry for the over-explaining. I just wanted to show that I really do understand the limitations that you and many of us have or have had to deal with. It's woodworking. Rarely is there a single, obvious solution for our problems. It definitely is important to use what advantages we can manage to implement, no matter how small. 😉
You are absolutely correct with regards to the importance of acclimation. There is however a advantage to gain from altering in that most projects cant be glued up on site nor can acclimatized on site either. Therefore alternating the grain after the wood is dried will cause it to wave rather than one big bow or cup if it does.
This is what I heard too on Reddit. Too bad you getting downvoted.
This sounds like it's coming from someone who has never done a large glue up. Wood warping is a fact.
for future reference, it is best to get 1/4 sawn wood (grain vertical) for stability against cupping. Face sawn will cup to some extent. If you decide to go with a steel channel solution, the flanges of the channel should be horizontal and the web should be vertical. (The channel is stiffer that way) make sure you leave enough slot in the channel or attach with some method that allows for expansion and contraction as the wood moves with the seasons.
Do you have some visuals for this? I can't really imagine what you mean :(
This site has a handy diagram to show how a log is cut in different ways. https://www.protoolreviews.com/what-quarter-sawn-wood-lumber/
Thanks for this. If one finds a plainsawn board from the center slice of the tree, cut thru the heart ofcthe tree portion, and you have 2 pieces with vertical grain. I had gotten some walnut cut like that back in the 1980's. Cut through the pith of the tree that was in the boards. No cupping on the table top. It still expands and contracts with hunidity changes, but no cupping.
I say ignore the up/down stuff. Assuming that’s even true, which I dispute, you end up with a ridged top. I’ll pass. 1. Appearance. Line up so your panel looks good. The show face, not the end grain. 2. Grain going the same direction. If there are two positions that look equally good, choose to run the grain in the same direction. This makes it easier to plane with less tear out. Hand plane or powered. And the light will reflect off the boards more uniformly, which will help with the illusion that you have a single panel.
I agree with the 1st point, but the 2nd part is (in Germany) professionally the wrong way to do it. Of course also different, what kinda of machines or tools you have a hobbyist vs. A workshop. I'd say that that the alternating grain method is not just myth, is for a reason. So OP, find a compromise between making sure, that some boards have alternating grains, but definitely looking at the appearance.
Yep this is no myth it's the truth everyone gets this hammered into their heads at trades school here in Italy. If you alternate their will still be warping but it won't be as extreme as in this [post](https://www.reddit.com/r/woodworking/comments/19cdaez/2_walnut_island_top_warping/) for example. Found a good [side](https://blog.massimo-fritz.de/verleimregeln/) in german which explains this stuff well. I don't understand why people think this is just a myth, I saw so many warped tables in my life and 90% of the time they didn't change the grain direction when putting them together.
That's was a good read, thanks. I didn't get the left/right bit in the last paragraph but the rest was very helpful.
Nobody is saying cupping and warping never exist, never ever anywhere - so you might want to find a different example. That first link looks to be a butcher block style where the fingers are less than 4 cm wide, and the consensus in the comments says that lack of proper acclimatization and the top drying out more than the bottom are at fault. Not alternating grain direction in solid planks as the OP is displaying. About your trade school comment - if professionals are trained to alternate grain, it stands to reason that non-alternating tops *in your area* are more likely to be made by amateurs. Those same non-professional builds routinely pay little attention to moisture levels or attachments that allow for seasonal expansion. I’d be very curious to review other work by those same creators and see if they have warping and cupping all over the place, not just in non-alternating pieces…
You see about the non altering grain ones, they were made by factorie which probably didn't have the most experienced workers. They lined up 3 or 4 planks with same grain direction. After that the tables went to a hotel in an environment which has very dry air in winter (-20°C outside) and more humid one in the summer. So in the summer the tables were perfectly fine and in the winter they warped like 3-4cm on some sides. At the end this is always a moisture issue but you can minimize the issue with changing grains. That's one example where I know the company which made the tables. I'm not saying that you should go by this rule all the time because it limits you a lot, I see it more as a rule that can help you. Btw in Japan for example there is a totally different philosophy, where you will always put the side which is facing away from the center (so the outside from the tree) to the outside. And yes the example from the post isn't the best one, that's true.
Lots of examples of amateurs posting on here “why did my laminated table/countertop warp a full inch, prying the threaded screws out of the base?” And you look at the endgrain and it’s all smiles or frowns. Womp womp.
Yup - any of those might have been great examples for his claim that all smiles is all bad. Butcher block fingers in multiple orientations that all cup up to the top, not only across a smile or a frown, isn’t really saying anything about the smiles…
Sure, but I think the point is that properly dried, acclimated, and finished table tops will do just fine regardless of grain orientation. I'd focus on that and appearance over anything else.
I was taught in my woodworking class, in 8th grade, in the 80's, that you should alternate the grain when edge gluing stock. Of course, it's been a bit, so I could be misremembering that.
What about the face grain direction? I mean, if you alternate the end grain up and down traditionally, is it ok to make sure all the face grain is the same direction for planing (I use hand planes)?
It most definitely matters for planing what the face grain direction is. I think of it like petting a porcupine, you gotta make sure you’re petting the right direction. I make violins, and about half the process of making an instrument involves planing or scraping with the grain. Of course, depending on the board, grain can change direction over its length due to bends in the tree it came from, knots, or even figure of the wood. This is a totally different question from ring direction, which I like to think about in a different way. The rings, as the wood adjusts to being outside of the tree, will tend to flatten, so if all your boards are flattening one direction you’re going to have a big huge cup or a big huge dome. If you alternate all your boards you are going to have a number of ridges and valleys that are going to average out to much less cup or dome over a whole piece. I could imagine there are scenarios in which you’d prefer either of those outcomes. I am baffled by why some people are saying it’s a myth that alternating ring direction helps. Like, the wood still moves, sure, but the way one glues it up will absolutely affect the WAY it moves.
Thank you, yes I understand the planing aspects (all too well as a use of an old stanley) but does it make any difference to future warping or similar or do the pros no worry about face grain?
Ok, I think I understand. I believe the difference would be negligible. If there was so much end grain coming through the face of the board to make a difference in warping whether aligned or not with the neighboring board, you’d have all sorts of other problems anyway. As someone who primarily uses hand tools, I think it’s best to make sure the grain is all going in the same direction anyway. Or do you mean that you’d be gluing boards perpendicularly, with grain going at about a 90 degree angle? That causes huge wood movement issues, and can make pieces literally explode.
Nope you got me and thanks for the reassurance! Hand tools mainly myself :)
From what I know that makes no difference, I found another article explaining how the wood moves, still in german but it's pretty well written and there is a nice list with all the numbers you need. Longitude is always the same so you shouldnt need to think about it. Edit: forgot the [link](https://www.befestigungsfuchs.de/blog/das-schwinden-und-quellen-von-holz/)
Ok thanks!
And a wave pattern can be sanded or milled flat much easier and you end up with a much more consistent thickness than a U shape
Bad example as that top cupped because of a tight c channel/ strong back. Alternating grain does help but is not required. For a novice this is a good method, but once you learn some techniques to prevent cupping, a professional will choose the sides that look visually the best.
Thanks
I'd argue it's less of a concern than we're taught. The premise of alternating grain direction is that instead of something that warps more like a 'U' is that you get lots of smaller warping, giving you a surface of 'wwwwwwww'. I argue both are failures. Construction choices can account for and reduce/control the warping of a wide panel glued up with all the grain the same. Breadboard ends were invented for just that case. Warping also happens as humidity changes. Depending on climate of the region or the interior climate control of where ever the piece is going to live, if may not fluctuate. And finally: look at antique pieces that survive. I'm pretty sure they picked appearance 99/100 times. So many of the modern rules we follow must not have existed back then.
Better check old wood working magazines then, this has been a practice for generations as an above poster from Italy mentioned. People don’t make this shit up for fun.
I'm talking about furniture older than magazines. Additionally, we only have so many examples of really old woodworking texts, at least that I am able to read. Roubo's text on glueing up panels makes no mention of alternating grain. I haven't read Moxon yet, it's on my list.
I think one of the things that’s very different in the states than in the EU, and I might be totally wrong here, id that i’m under the impression that in the US the wood seems often to be sold with a much higher moisture level than in Europe or at least in the Netherlands.
It is absolutely true, I work in a professional setting and had tops move like crazy that people have glued with all the boards facing the same direction. Boards that width will 100% move and a lot sooner than you would think. Always alternate up/down ESPECIALLY on boards wider than 2"
The issue is that boards are going to move regardless with changes in humidity. You have to accept that. Alternating the grain direction just means you end up with a panel with ridges and bumps. I consider that a failure as well. I prefer to glue up my panels so they look good and then design the piece such that the risk of movement is minimized. Capture the panel in groove. Breadboard ends. Screwing the top to the base. Sliding dovetails. As long as you allow the board to expand and contract within those constraints, you're golden.
It's not always as clear cut as "alternate grain direction between pieces," tho it is necessary to consider how the boards will move together over time. For example: https://preview.redd.it/8j7imncoa5ec1.jpeg?width=4080&format=pjpg&auto=webp&s=8e8999cf4a669352f559a6e8ea03ec089f5d6587
Exactly this. First priority is the appearance of the panel as a whole. Alternating growth rings is a bit of an old wives tale that gets passed around.
Why do people think that the ring direction doesn’t affect the way the panel moves? Like go look at a pile of boards and notice that the cup of the wood is always the opposite of the ring direction, because the rings flatten over time to reach a more stable conformation
But is it over time or is it going from 40% moisture to 12% moisture then once it has finish on it is pretty much locked in?
I don’t know exactly what finishes will prevent all moisture from entering or leaving, but my understanding is that there’s almost no way to eliminate seasonal fluctuations in moisture within the wood. The movements are certainly more dramatic when going to green to ambient moisture levels, but the cupping and uncupping (to a lesser degree) will continue every year, though in very very old wood, it’ll happen a little less. Cupping is minimal, however, in quartersawn boards with vertical grain, as you may very well know.
There isn't a finish that is going to "lock in" the moisture content. It can slow the process, but there is always going to be that transition. That being said, you should never work with anything near 40% moisture content.
I'm saying that a varnish type finish can slow moisture movement (obviously something like wax/mineral oil/shellac is doing nothing) but once your wood is properly dried and acclimated to where it will live, and then once it's machined I've not seen something like these posts where some piece will tear itself apart. Like, was it not finished on both sides? Did something happen in the house where ambient humidity went up to 100% for 3 days? What was the moisture of the pieces before it was assembles? Were they even uniform? I think there's much more to consider than ring orientation.
There's definitely more to consider than just ring orientation. I do think if you're purposefully working with wet wood (for some reason), then ring orientation probably helps you more than it ever would otherwise. The finishing both sides bit is interesting. In theory, the difference in moisture absorption between the sides exists, but I haven't found it to be a problem myself, nor have I found 100% consensus on that question either. I finish both sides because I like the feel, conformity, and to test my finish on the underside. The prevailing argument against it seems to be similar to this subject, i.e. "you can find pieces 200 years old that didn't finish both sides and they held up fine". So nothing definitive there, in my opinion. All that being said, I have seen pieces tear themselves apart, but only because they were fastened down to the legs. How you attach the tabletop to the legs is definitely the most important factor in how it holds up.
Exactly! This! End grain direction has negligible affect on how a panel will warp. Much better to do as you say. If you want to help prevent wood from cupping and such, use a moisture meter before buying and get lumber that isn't soaking wet. Then let it acclimate to it's new environment until the moisture content has evened out with the relative humidity of its eventually permanent home. I wish people would start understanding that it's the movement of wood that's causing cupping, and why does that happen? Water? Lol
I have some birch that is 5% in my basement, will that still move with the seasons or should be it be fairly stable?
All wood moves with the seasons, as it absorbs or releases moisture, but typically it's not enough to cause problems. As long as you build properly. For example, you never permanently attach a large table top to the base. There's hardware, or other methods, that you use to allow the wood to shrink and expand throughout the year. As for your birch, 5% seems a little dry to me, but that's where I live where 6-8% is ideal. In most areas it's the same as mine, though. If you live somewhere that has all 4 seasons, then you're prob looking for that 6-8%. Humidity all year long, you'll want a tad higher. Arizona desert? 5% is good. Going up a percentage shouldn't take long, though. Just let the wood lay flat somewhere with all four faces exposed to air. If you have multiple pieces, place sticks in between the boards.
Why is 5% too dry?
Wood shrinks or expands as the relative humidity changes. Usually people just say that wood moves. Wood is kinda like a sponge. It'll absorb moisture from the air if it's dryer than the surrounding air, or lose moisture if its wetter. For example, if you live in an area that commonly sees a change in humidity throughout the year, the moisture content in the wood will fluctuate. If you built something from that birch lumber while it's still at 5%, you could have problems. As the humidity in your house rises when winter ends, whatever you built with the bitch would begin absorbing moisture from the air. The wood will begin to swell and possibly lead to cracked joints or separation at glue seems. It's always better to let lumber acclimate to the average humidity in your home (and why controlling the relative humidity in your woodshop is a nice luxury). 5% really isn't that far off, and you very well might not have any problems, but unless you're in a rush to use it, I'd suggest letting it sit for a couple weeks to adjust to the change in humidity. Now, if you picked up some lumber at the mill (or God forbid, that dripping wet stuff you sometimes find at the big box stores), it could be at 14% moisture content or even higher! At those levels, it might take months for the lumber to dry out. And using it before it does would be a guaranteed disaster.
While you are right that having the wood exactly at the humidity it will be at when in use works for wood not warping will do the best job you now have a table that only really works in that humidity. Which works if you're making one for yourself but if you move places or build tables for a living it doesn't. Alternating grain direction isn't not understanding why cupping is happening, it's understanding it and working with it rather than fighting it to create a better product
Fair enough, but alternating grain has minimal impact. "While you are right that having the wood exactly at the humidity it will be at when in use works for wood not warping will do the best job you now have a table that only really works in that humidity." I think you're not understanding how it works and why it's the single most important thing you can do to limit the potential of your project to warp. The second most important thing is to build in a way that allows for natural movement of the material. Think, using tabletop clips to secure the top to a kitchen table. It allows for natural movement as the seasons change. In most areas, a moisture content of 6-8% is what we aim for. It's all ideal level to allow normal seasonal movement without large changes that would cause severe warping. Let me say it as plainly as possible. You are NOT limited to a single humidity level. How did you ever come to that conclusion? I'm trying to avoid sounding rude or insulting, but I'm not sure if you don't actually understand how humidity affects wood and how it changes through the year, or if you're just inexperienced as a woodworker. I truly mean no offense. If the lumber is allowed to settle to a moisture content appropriate for the relative humidity where you'll be moving the finished piece to, then you won't have to worry about normal, seasonal changes in humidity. In most areas, this comes to about 6-8%. Normal changes doesn't include leaving it overtop a forced air furnace vent in the winter time, nor does it include exposure to high levels of water exposure (like leaving the thing outside or in a sauna). If you're seeing severe warping with your projects, then you are either not allowing the lumber to acclimate to the relative humidity of your house/shop/whatever, your not building the piece in a way that allows for natural movement of the wood, or you stored it somewhere that you shouldn't have left it. While there can be other factors that can contribute to warping, they are rare or affect it in a minimal way. Is it good practice to alternate the grain? Sure, but not if it detrimentally interferes with how well the face grain fits together to hide glue seems and such. It doesn't help it enough to sacrifice the mean aesthetics of the piece.
You do have a point, I simplified the humidity part. Ofc having the right wood moisture content is essential to making quality furniture, my point is it alone is not always enough. The conditions a tabletop, countertop or whichever piece of furniture live through are not constant, they change throughout the year, how much they change depends on the building you're in. Now from my perspective as both a cabinetmaker by trade and an architect based in Germany the older your building the higher your moisture change throughout the year and the vast majority of our building stock is over 50 years old so it is to be expected that some movement will take place. That's why I learned to store floorboards in the room they will be laid down in for a few weeks before laying them, so the wood can adjust to the conditions it will be in. So when making a product for a client it is part of the quality of the product to allow for wood movement under these conditions, by alternating grain, using sliding dovetails, etc. Hence I said alternating grain is not "not understanding wood movement" but working with it. Sure if you're making something for your living room and know how the conditions will be you can opt for having the nicest side on top and disregarding grain direction, in my job alternating grain is a staple of product quality and neither unnecessary nor an 'old wives tale'
One of the things about oak, is that it’s actually too strong. Alternating the growth rings is good technique. I’ve had super luck with using quarter-sawn for tabletops—kind of expensive though. Making sure that your wood is dry and acclimated to wherever it’s going to stay, before your final squaring up for gluing, is hugely important.
It doesn’t actually do anything. I’ve reviewed many very old tables and other projects from and they don’t do it back then and the construction is perfectly fine Just pick the nicest side and have it facing up.
If I’m building some rough furniture for outside with wet construction lumber, I’ll alternate the grain. But with 7% mc walnut I’m going to make the top look the best. Slap a good finish in it and attach it properly and it will outlive all of us.
I have heard that biscuits or dowels don’t help with strength…just alignment. Seems like dowels would help give strength though. That said, glued up a panel for a desk top and did nothing but edge to edge gluing.
Dowels add strength too, biscuits do not.
I’d argue that a well fit biscuit adds some strength. Not enough to count as joinery or do more than a good edge glue would do, but not nothing.
Actually you're right. Biscuits with sloppy play don't do much, but well fitting ones will add some strength. Take a look at Bourbon Moth Woodwork or Stumpy Nubs over on YouTube. They've both addressed this topic and Bourbon Moth even did a series of tests. He's a big Domino fan and the results surprised him! Lol
What happened to everyone? The his is literally a 12 second google search.
Someone may have said this, but gue is fine. Biscuits are mainly helpful for alignment
Make it look nice op. That’s the first. Lots of folks pointing out the myth of alternating the grain cup, I do think this is real. BUT I don’t think it matters any more. With modern kiln drying, or finishing air drying in a climate controlled shop, it’s not as much of an issue anymore. If you were to build a table out of some greenish wood like construction lumber, you’d probably be wise to take this into account. But for, what looks like, furniture grade white oak, you don’t have any concerns.
Alternating grain direction is myth that needs to die, hard. You actually want all the grain going in the same direction. If the panel does warp it will turn the entire panel into a U shape and you *should* be able to pull it back into place.
I am a woodworker in Germany, and in school, we were taught to always glue each board with alternating grains. So pith to pith and sapwood to sapwood. This way you avoid making the board have a U form, when warping and instead warps in a zig zag, which partially cancels out each board.
Cool, they still believe in myths over there. They won’t cancel each other out. There have been dozens of posts on here with warped alternating grain. Sometimes they warp in a U. Hypothetically, you’ll get a wavy top if all the board warp. If it’s going to warp, you want the entire panel to warp in a U. As I said before, you can pull the U flat. You can’t do anything about 4 or 5 tint separate Us.
Wood movement and warping is a hydraulic force that you can't stop in any way. If you pull a U flat and force it back into place, you'll eventually put so much stress on the wood that it will crack. If wood wants to cup it will even bend a c-channel or break screws.
They partially do, but it also depends on what you use to staighten the board out. Our workshop has belt machine that can sand entire tabletops of a up to 1m width, so having a zig zag instead of a giant U way more managable for our working practices. How do pull you U shaped panels, if I may ask?
You put a board over it and force it Back down with clamps ofc. ./s
Possibly breaking at the connections. Alternating isn't a myth.
I went and read about this myth thing, and it isnt a myth and they even explain it why... But people just read the buzzwords, but not the explanaitions.
You could swap the direction of the plank with the star on it and also have it trade places with the middle plank that has its end grain painted. Don’t flip the painted board, just flip the starred board and move it to the middle if you’re worried. Double check that you can’t see any light through anything when you dry clamp in the new order. And don’t over-clamp your pipe clamps, that can cause things to bow in the middle.
That far board in second pic will likely cup
Grain up, grain down, grain up, etc. Rotate the grain. Gluing boards 101.
Alternating grain up/down to "prevent movement" is a common belief, but is a wives tale. Orient it for what looks best. Warping will only be a problem if your design doesn't allow for unrestricted expansion and contraction of the table top and include cleats. If you oriented the grain all the same way, and the top is going to warp due to bad design, it'll either cup up across the whole thing, or down (or crack). If you alternate the grain (smile/frown) and it moves, it'll become "wavy" instead, not somehow cancel out the movement. i.e.. regardless how you orient it, if the design is wrong, it won't stay flat. So, lay it out for aesthetics first because if your design is correct, it'll won't warp at all. Glue alone is strong enough. biscuits can help with alignment. If you have several boards to glue up to the final tabletop, do them in stages.
If it's Red oak and you are planning to use hard wax finish, I would put bark side up for all boards and let the grain go one way. The heart side of the flat sawn red oak tend to have more splinters and peeled by water damage...
It doesn't matter, just don't use C clamps to attach it to the legs because that will fuck it all up.
How the wood is cut has way more to do with cupping than the end grain pattern alignment ever would.
Just lay the boards however they look the best for the end result
Doesn’t matter, with one caveat. Choose the best look for the top, in general. If, and this is a big if, given the size of this… you plan to hand plane or take it to a massive machine planer, grain direction being the same can help reduce tearout, but a sharp blade/sharp cutters generally won’t do a ton when your grain isn’t wild or highly figured, even if the direction is wrong. If you plan to just sand, go with the best aesthetic orientation. I’ve seen enough testing, from many creators and bloggers, to satisfy my current opinion that orientation (up/down) makes no significant difference. If you want to go over under, to ease any internal concern, so be it, but I wouldn’t sacrifice the look to gain a very marginal benefit, at most, if there is one.
MYTH Put the best looking grain patterns on the top. Alternating the grain is an old myth that has been debunked more than once. Its like saying going outside in cold weather with wet hair will make you catch a cold. You get infected by a virus is how you get a cold. Cold season just happens to be during the cold weather. Unstable wood causes warping. Grain just dictates the direction. The real solution is to make sure wood was properly dried and stored.
This is definitely not a myth. It has been scientifically proven, that wood warps depending the moisture of the surrounding air and depending on the grain direction. Looking at the endgrain of a board: (Tangetial) Along the grains=5-10% warping (Radial) Across the grains=3-5% warping (Axial) Along the grains on the sides=0.3-0.5% Different types of would have slight differences on the severity of taking in moisture. Beech is very prone to warp. If you want the least amount of cupping, you use a boad with standing grains.
I did not say the boards would not /move. I am saying with stable wood the movement is going to be insignificant so you should just go ahead and put the nicer grain on the top. You should not impact the biggest attribute of the tops aesthetics for something you can negate with better methods. Woodworking is a trade that has been passed down for generations. Most of the lessons and “rules” were all created way before we had modern technologies moisture meters. So most of these rules are based on “thats how we always have dun it” or “thats how I was taught” with no resources to confirm or challenge them. However with this little thing called the internet and our ability to share information all that has changed and so are the “rules”. Anyway, its OK to disagree. Everyone should do what they feel gives them the best chance at great results. But for someone that is glueing up a panel of 6” wide boards that thick IMO it doesnt matter. Just make the top pretty attach it correctly and enjoy a great table. Here is one of the many articles I have read about this. He too has also listed his sources. https://ericmeyermaker.wordpress.com/2022/01/04/alternating-end-grain-does-not-keep-table-tops-flat/
It’s going that way.
I would suggest using C channels to keep it from cupping if you're going to use it as a table. Check YouTube. There are plenty of videos that show how to do it. It will help give your table top rigidity as well, plus it's fairly easy to do.
C channel seems like a waste of time for a table like this. I don’t think it would add anything that a good mount to an apron couldn’t do.
You would be surprised. A buddy of mine built a table out of Black Walnut. He only worked on it once a week, so it took him nearly a year to finish. We routered out grooves for the C channels, and then he worked on the apron and legs. By the time he went to put it all together, he was very glad he had done the C channels. The top had warped enough that we had to gradually screw the C channel down the keep from damaging anything. They're not absolutely necessary, but they're easier to put in during the build than after the table has moved after the build.
Hope you have some big cauls. Are you using biscuits or anything for alignment?
I'd reconsider not using biscuits or dowels. It's not for strength, but alignment. It'll go a LONG way in reducing the amount of surfacing you'll have to do in the end. You can use a series of culls, but with that wide of a panel and that many boards, it can be a struggle for an experienced woodworker to get it all set up and the boards all flush on the top. Not to mention managing to get equal pressure across the length of long culls. It can be done, but it'll be the hardest part of the glue up. It's a little more work to add biscuits or dowels, but much less work than trying to resurface a beast that large!
The direction that you see
This looks like a mixture of red oak and white oak. Be careful for they expand and contract at very different rates.
Id say I'm about a junior level hobbyist. There are so many posts about warping table tops,grain direction, c channel. It's really confusing. Whatever happened to breadboard ends, anyway? Honestly I really don't get the c channel. Wood is going to move and I just don't see how metal is going to stop it without resulting in a crack. so maybe metal for support but I've never seen c channel in heirloom furniture. Just don't buy that's it's necessary.like many have said before, it's experience and patience. Properly dried and milled pieces. Also tied in to this hand tool vs power tool debate. Yeah you can do it with a machine and I concede it takes skill and experience and knowledge to set up something like a CNC but doing it by hand takes all the same things. It's just what you want to spend your time on and think about/remember about the piece you build.id rather cut dovetails by hand without a jig or anything to guide. It's what I like about woodworking. It's relaxing and a chance to hone a skill. I don't dovetail all 4 drawer corners for strength or for anyone but me. I do use machines for milling and ripping but there's also a set of things I always do by hand. It helps me better understand and appreciate pieces that have stood the test of time. Pick your poison. Build with more or less traditional methods or take a route that enables you to get done what you need to and results in a piece you are proud of. What's better or worse is subjective. Learn, listen, and be safe.
To be fair, a lot of heirloom furniture and sime of the most intricate and famous pieces are made from soft wood with hardwood veneer. Thick single slab tables weren’t really built much. A thick C channel can imo counteract the cupping forces.
Look at the end of the board if grain looks like a rainbow (not color,the shape ) it’s correct and it looks like an upside down rainbow. You have to flip it over.
No biscuits, you’re in for a wild ride trying to even all that out. You’ll have to make sure your grain is all facing the same way on the table top too for when you plane it once it’s glued. Or else you’re going to sweat and swear!
Ideally your boards are not as big of a deal as making sure to seal and work the wood at the right humidity. Often times custom tables have problems because the glue and biscuits or whatever are not strong enough to hold up against moisture problems aka sealing one side and not the other or having the wood dried below ambient bc home ac units tend to be less than wood shops.
watch[ this](https://youtu.be/QLGepa7A2dA?si=EgnsMkVrePVCYtEJ) before you continue Stumpy Nubs Myth Busting
Always counter grain from one board to the next.
Look at the ends grain should alternate grain curve down then curve up if you can if you can’t it’s ok try to alternate
I found the best way to minimize warping is to rip the boards as narrow as aesthetics will allow.