Tung Oil for Table Tops
Tung Oil is not the toughest coating, but it's easy to maintain and repair. July 28, 2008
Question
I'm making a custom dining table and the top will be mahogany with a 3 inch border of teak, to match the client's existing chairs. I expect to use tung oil and polishing to create the final finish. I have not worked with teak before, nor have I done much work with tung oil. I have had lots of french polishing experience though, as a luthier. I have a couple of questions.
The client is looking for some contrast between the teak and mahogany, but with a natural look to the finish. Since both woods will become richer over time, will they become more similar or more contrasting over time? If I stained the mahogany to create a greater contrast, are there any issues with the subsequent tung oil finish, such as reduced absorption, drying issues, bleed, etc.?
Forum Responses
(Finishing Forum)
From contributor A:
Whether you will have issues will depend on the type of stain you use. The tung oil could pull the dried stain back up, making a big, smeary mess. Actually it depends on both products. There are a lot of tung oil products on the market, but not all of them are actually tung oil. Some are true tung oil, some are a wiping varnish/oil mixture, and some are just rubbing oil.
If the solvents in the tung oil you use are strong enough to redissolve the stain, you will have a problem. I would shy away from using tung oil on a table top regardless of any stain problems it may create.The majority of tung oil products just don't have the durability or moisture resistance needed for a table top.
From contributor B:
You can use a dye to color your wood with water type - then apply your polymerized tung oil – Southerland Wells brand - over the dyed wood. It will take about 4 to 5 coats and each coat should be burnished in with scotchbrite and allowed to dry according to directions or longer in cold weather. Southerland Wells is a pure tung oil with good build.
From the original questioner:
Thanks for the suggestions. I know that some of the tung oils are a mixture, and I even had someone suggest making up my own mix. I'll mix up some different stains and aniline dyes and test the tung oil on some test pieces. I'll try and get a good range of products and post the results for interest's sake. I don't lack for either scrap mahogany nor stains and dyes and it could be fun.
To contributor B: Does the S-Wells brand have some durability? In some discussions with the client, I let them know that, in general, they may have to follow a plan of re-applying tung oil, usually once a year. I plan to give the top a good build over the course of two weeks with the following schedule: 1 per day for a week of flood-wipe-drying-polish, 3 more times over 1 week with the same. Once dried, is a once a year reapply of tung about right for a functioning dining table given this type of initial build-up application? Sorry for all the questions. Most of my finishes are typically on instrument restorations, which means shellac and french polishing, or NC Lacquer sprayed and machine buffed. This is my first time with an oil finish.
From contributor B:
Polymerized tung is what Southerland Wells sells. It should not be used as a wipe on - let set - wipe off finish, nor should other poly tungs be. You have to burnish the oil into the wood. Apply, take a scotchbrite pad (you can even put a piece on a pad sander or D.A.) and use this to rub into the wood till it's absorbed as much as possible. Spots that soak in can be handled by applying more to just those areas or by bring excess oil on top to those areas while burnishing each coat. Any remaining light film is removed with a rag, paper towel, etc. or if very thin just leave on. Let it dry the recommended amount of time or longer if cold, and apply the 2nd coat and so on till you achieve the look you desire. Tung is pretty water resistant and household item resistant to mustard, and others - but do not use alkaline or ammoniated cleaners on it. A damp rag or emulsion type product is good for general cleaning. Some suggest a wax on top for more protection but it's just something you'll have to remove when applying the next coat. Five or six coats will be fine for a top with annual or biannual renewal, depending on how much use it receives. For repair, it's normally just a matter of sanding the damage out and re-oiling at worst or steel wooling with new oil at least. It's easier than shellac to repair once you get the hang of it.
From contributor C:
I would seriously reconsider the use of any type of oil finish (tung, linseed, oil/varnish, etc.) for a dining table top. They're not very durable, and they also easily allow moisture (and other substances) through, which can discolor the wood below. You can refer to the AWI table which illustrates the durability and other properties of the most common finish systems available. Oils are the least durable and protective finish shown. Catalyzed conversion varnish (CV) is a good choice. The best choice for your application would probably be a catalyzed vinyl. Sherwin Williams makes several catalyzed vinyl finishes available in various sheens. Catalyzed vinyls are usually low in solids, and will give a "close to the wood look" if you're trying to avoid the look of a built-up finish.
From contributor B:
To contributor C: What do I do with my 35 yr. old tung oiled dining table then? It's in near perfect condition. Yes, it's had water damage, alcohol spills, all kinds of food and liquids, cigarette burns, nail polish remover, craft glues (hot melts), and yet I've been able to keep it pristine without having to strip, or use VOC's or haps emitting materials to redo any of the mentioned damages. There are two different thought processes here. One is a seemingly higher degree of protection versus ease of repairs when the more protective finish fails (and it will fail eventually no matter what type of surface coating it is). When it does, then you are left with the problem and decision as to repair or face removal. Tung virtually never has to be removed for any normal damages the table might receive. I cannot say the same for any other coating accept for shellac and other natural resins or wax.
From contributor C:
I guess you're into maintenance. I agree - if you keep up with maintaining an oil finish - and you're careful what you put on it - it'll hold up ok. I've finished coffee tables, end tables, and kitchen and dining tables with tung, linseed, and varnish - oil blends. And, I've had to refinish them in as little as a year because of moisture damage, etc. Potted plants in saucers are the worst because the moisture accumulates underneath, and is usually not discovered for some time. Sometimes, this can wreck any finish. Most folks are well-intentioned, but they'll lapse in the precautions necessary with these finishes. I've found that overall I've had better luck with the catalyzed finishes such as CV and vinyl. For a while, unfinished maple butcher block tables were popular, and the stores selling them usually sold them with instructions for the owner to seal the table either with mineral oil or a varnish - oil blend. I can't tell you how many I've seen with black stain rings, etc. because the owner didn't re-apply the sealer frequently enough. I've usually re-done them with either CV or vinyl. I just refinished a tropical wood coffee table originally done with an oil finish (not by me) for a client with extensive water ring damage to the top. I used CV.
From contributor B:
I agree that maintenance is necessary and that most people do not want to take their time to do so, but I have never had to refinish any tung oils I've done. It's normally easy to repair. The addition of film forming coatings with tung is much more of a problem than polytung - normal tung non polymerized is what usually causes the problems. Polytung at 6% acid level polymerization is a different animal - much more durable and better quicker build. I believe those finishes that are easiest to repair and don't require full removal are a sounder choice than having to strip cat finishes. Although tung may not always be totally green it far surpasses those you've mentioned in that area. I love the fact I'll never have to use MC or other hazardous strippers to alleviate any surface problems that occur with tung.
