Ammonia fume wood with an existing oil finish?

[Jim Martin]

Hello All:

Today I took out a bunch of oak furniture that I built years ago for a new coat of oil finish. Getting it out in the sunlight I was surprised by how yellow it looks now (its about 9 years old). Almost looks like someone applied Golden Oak stain which I do not like so much.

The wood is quartersawn oak with several coats of oil applied originally and a recent coat of Tried and True Varnish Oil.

Would I have any luck trying to fume it now? My impression is that oil finish penetrates the wood so it might not let the ammonia work. On the other hand, ammonia is pretty potent stuff so it might penetrate the through the oil. Yes, I could test a scrap but I thought I'd post this question before I go shopping for ammonia, protective gear, etc.

Thanks in advance,

Jim

[dingbat]

Oil yellows. Always does, always will. Linseed goes bilious yellow in a few months over a summer, better oils take some years to get there. Only way to really stop it is to use a reddish oil instead. It still adds some yellow, but at least it now looks an attractive brown, not jaudiced..

Only if you can get the oil finish off first. You _might_ get some ammonia through the oil in patches (especially worn edges), but any colour change will be patchy as anything and not a good look.

I've successfully fumed oiled oak, but only on Craftsman-style stuff where it was all square corners and easily sanded free of finish first. Even then I had trouble with any sorts of moulding (but they were already quite dark and the variation wasn't obvious)..

Also if there's any shellac around, ammonia has a bad effect on that.

[nailshooter41]

SNIP

I don't think you will get what you want by fuming. Fuming works best on raw, unfinished wood untouched by anything else. Since the wood has been sealed before, I think at best you would have a blotchy finish since you would never get all the remnants of the sealer off the wood.

I think you would be better served by getting some different stains in the family of coloring you want and then mix and test until you get the right color. If you are not stripping and are concerned about blotchy finishing with the pigment stains, try using some of the better gels.

Robert

[Fly-by-Night CC]

Do you remember what type of oak it is? When fuming, the white oaks turn a pleasing dark brown - but the red oaks will often turn an unpleasing green.

I'd certainly try a test to see what happens - you many find the ammonia gas will soften the existing finish and ruin it. You may also find that it works perfectly to what you're after.

[Schroeder]

You have some good advise from others here Jim, the only thing I would add is that if you do decide to fume, make sure you use 29% (pretty much only available from blue print shops).

Good luck! Schroeder

[Jim Martin]

Yes, white oak so I should be okay for fuming.

Agreed, I'll oil up a scrap and see how it works.

Thanks,

Jim