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Finish Repair

2K views 6 replies 6 participants last post by  skcj213 
#1 · (Edited by Moderator)
Good morning all!

I am looking for some tips on repairing the finish on my dining room table. A few months ago some acetone got spilled on the dining room table ruining the finish on a roughly 1.5 square foot area of the middle leaf. The table is oak with what I believe to be a polyurethane finish. The have a couple of specific questions:

1) How can I verify the type of finish?
2) The table has had furniture polish (like pledge) applied to it for several years. How can I effectively clean the polish so the new finish will not fish eye?

Any other tips would be greatly appreciated. Thanks in advance to all who respond.
 
#2 · (Edited by Moderator)
Was the table built in a home-based work shop, or was it constructed in a cabinet shop or factory? If the former, it might well have a polyurethane finish. If the latter, then I very much doubt that it has a poly finish for the simple reason that poly takes too long to apply. Most cabinet shops or factories use either a nitrocellulose lacquer or an acid cured finish like pre- or post-catalyzed lacquer or conversion varnish which are easy to apply by spraying and which dry in seconds or minutes. To identify the finish, apply a small amount of lacquer thinner to the surface. If it softens the finish, then you know that it's a nitrocellulose lacquer and you're in luck. Use a rattle can of lacquer to reapply the finish to the damaged area after you scuff sand the surface. If the lacquer thinner doesn't react with the finish, I'd consider stripping and refinishing. Both polyurethane and catalyzed finishes are difficult to repair invisibly.

As for the problem related to the furniture polish, I don't envy you. As you know, those products often contain silicone. In the case of oak the silicone is likely to migrate into the wood grain, making the problem rather difficult to eliminate completely. Wash the surface thoroughly with VM&P naphtha and a scrub brush. Then follow with more naphtha and plenty of clean rags, changing rags frequently so that you don't just smear the silicone around. Next, spray on a thin coat of dewaxed shellac and follow that up with lacquer as described above. If you decide to strip and refinish the table, spray on a coat of either dewaxed shellac or a coat of vinyl sealer. Both of those products have worked for me in the past.
 
#3 ·
You can get a scrap of wood, put poly on it and see if acetone will give you the same result. I am thinking it maybe lacquer instead. Regardless, of whether it is veneer or solid wood, you need to sand that leaf bare and put a finish on it. It may look shiner or cleaner than the rest of the table, but the center leaves always do if they are not used very often.
 
#4 ·
Sounds like lacquer though I could be wrong. I wouldn't expect other finishes to take severe damage from acetone if it were removed immediately. Some people use shellac as a sealer on grainy woods prior to applying an acetone-based wood filler.

Pledge is evil stuff.
 
#5 ·
It is a pretty quick job to refinish the whole top. I wouldn't expect the finish to match if you do a spot repair. I have refinished tabletops before, without refinishing the table base and it worked well.
 
#6 ·
I agree with pintodeluxe, to help avoid issues, just refinish the entire top.

Here's a link to a Wood Mag article about figuring out which type of finish you have. http://www.woodmagazine.com/materials-guide/finishes/what-finish-is-that-anyway/

Also, you can put a coat of de-waxed shellac, on anything, and then top coat it with anything you want.

Lacquer is not the appropriate finish for a table top. Go poly.
 
#7 ·
Thanks to everyone for their responses. I'll try to answer all of your questions in the order received.
Fisherman - The table was made in a factory. Your comment makes sense on the finish type, it is likely lacquer.

Pintodeluxe- The table is round without the leaf, we leave the leaf in all the time. I'd rather not refinish the entire table.

I think I will try refinishing just the leaf first. If after refinishing the leaf it is too different than the rest of the table I can always do the rest.

Again, thanks to everyone for your help. It may take a bit to get the work done, I always seem to have a backlog of projects. I'll be sure to post the results.
 
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