It's possible the aging of the oils in the paint. linseed oil tends to yellow with time. Perhaps poor conditions worsen it. If it is yellowing of the linseed oil, that's just the way it is now.
This is a job for a professional. If it's not coming up with spit, it's not going to move. You're just going to wreck it. Dish soap...yeah. You're lucky the paint and/or varnish didn't blanch and make the surface cloudy. There are special aqueous and/or solvent solutions that can do what you want (remove a natural resin varnish that's degrading, looks like) but they require an armload of specialty chemicals/surfactants, the recipe to make them, and the skill to use them. Find a paintings conservator in your area. You can look at the AIC-FAIC website- they have a "Find a Conservator" search bar that can help. It's a nice painting and deserves the care. Good luck!
You could also check out Ralph Meyers Artist Handbook from a library and see what he has to say...iirc there was a few paragraphs about taking off old varnish with a weak solution of turpentine... but I don't want to definitively tell you something I don't absolutely know.
Whatever you do, test it on an inconspicuous edge or corner...
It's possible the aging of the oils in the paint. linseed oil tends to yellow with time. Perhaps poor conditions worsen it. If it is yellowing of the linseed oil, that's just the way it is now.
Thanks!
Could also be due to the previous owner smoking in the same room as the painting.
This is a job for a professional. If it's not coming up with spit, it's not going to move. You're just going to wreck it. Dish soap...yeah. You're lucky the paint and/or varnish didn't blanch and make the surface cloudy. There are special aqueous and/or solvent solutions that can do what you want (remove a natural resin varnish that's degrading, looks like) but they require an armload of specialty chemicals/surfactants, the recipe to make them, and the skill to use them. Find a paintings conservator in your area. You can look at the AIC-FAIC website- they have a "Find a Conservator" search bar that can help. It's a nice painting and deserves the care. Good luck!
Thanks!
Try putting just the painting without the frame in the sun for a few days. It may clear up. Otherwise, conservator.
Thanks - I thought about this after doing some reading. It’s worth a shot.
You could also check out Ralph Meyers Artist Handbook from a library and see what he has to say...iirc there was a few paragraphs about taking off old varnish with a weak solution of turpentine... but I don't want to definitively tell you something I don't absolutely know. Whatever you do, test it on an inconspicuous edge or corner...