Removing Tung Oil from Existing Finished Cabinets

How do you get Tung Oil off cabinets without damaging the underlying previous finish? That depends on the nature of the underlying coat. May 6, 2014

Question
I have a client whose hired help put tung oil over the existing finished cabinets and it has changed the color to some degree. They've asked if I know how to remove this. I don't know if the original cabinets (about 30 years old) from Woodmode are finished with lacquer or conversion varnish. Any ideas as to how to get the tung oil off without harming the original finish?

Forum Responses
(Finishing Forum)
From contributor R:
Mineral spirits.



From contributor M:
That's quite the problem you have. If the finish on the cabinets is 20+ years old, it certainly has begun to deteriorate. Proof of that is the tung oil changed the color. If the finish was intact, no change of color would have been noticeable.

Mineral spirits will do nothing except force the tung oil deeper into the pores, thereby making it even harder to remove. There is no easy solution. They could be stripped and refinished, but short of that I doubt you can do much.



From contributor R:
I assumed the "somewhat" descriptor to the finish color was from the amber colored tung oil. Not that it got past the finish and into the wood. Don't strippers just remove the film? Maybe stripper will not remove all the tung oil either.



From contributor J:
I have used tung oil for 35 years, and I have refinished many a kitchen. If the finish under the tung oil is conversion varnish, I would try wiping the tung oil with lac thinner (it may remove the tung oil without harming the CV). The CV tends to stand up to some paint removers that I have used. You will more likely than not need to respray something over the CV after you remove the tung oil. Be careful not to soak the tung oil and try to do a test on the back of a door first. Failing that, refinish.


From contributor Q:
At this point I wouldn't worry about the original finish. I work with tung oil often. I'd prefer using pure turps to remove it. As a conjugated drying oil, tung oil will auto-oxidize faster than linseed oil. How long has it been on the piece? I'd just try to solubilize the tung oil and just keep flooding it and wiping off as many times as it takes until no more comes off. You might even try wiping down with DNA afterwards if there appears to be any residue left. If the resultant finish is still funky, then stripping will likely be needed.

Where are the cabinets? Kitchen or somewhere else? 30 years ago? What is the wood species? Painted (opaque) or stained? Try some lacquer thinner and a Q-tip on a small area out of sight. If it softens, it's lacquer. If not, probably CV. If it was shellac it came off with the DNA. If it is lacquer, see what the lacquer thinner will do over the entire piece and re-shoot it, if necessary. If the finish is still good, maybe a touchup will work.

After 30 years it probably needs to be cleaned and maybe even re-finished anyway. How many cabinets and where are they? Sounds like a lot of work if they need to be re-sprayed. Make sure you get paid. I suspect it won't be a trivial matter, even if the chemistry involved is.



From the original questioner:
Thanks guys. The cabinets are in the kitchen and there's probably 20 lin ft of wall units and about the same for base units. Cabinet manufacturer says the cabinets received CV topcoat. Don't know how long the tung oil has been on there. Client is going to try mineral spirits on inconspicuous area and if that doesn't work he's going to try lacquer thinner. Said he'd call me after he's tried those 2 products and let me know how it goes. If he's satisfied with either, he wants to hire us to do the rest of the units the same way. Thanks again!

By the way, the species is maple and stained.



From contributor D:
If the cabinets were originally finished with CV, plain tung oil would not be capable of uniformly changing the color of kitchen cabinets. Even with tinted tung oil would be difficult to achieve a consistent finished result. I can understand the finish being darker in areas where the original finish had failed and the tung oil was able to make contact with the wood directly. This would result in a very blotchy/patchy finish.

If the color is uniform the tung oils most likely hasn't penetrated the finish and you will be able to remove with solvent - LT, DNA. You will need to use a soft abrasive like green scotchbrite pad and light touch to lift the tung oil.