I’m in the process of refinshing my solid black walnut dining table. My friendly dog got carried away stealing xmas goodies and put several deep scratches in the table. So far I have stripped and sanded and applied 3 coats of Tung oil. I chose Tung oil because repairing an oil finish is usually easier than a varnish type finish. However my thinking now is maybe an oil finish may be easier to repair but perhaps I may be faced with more repairs because the oil is not as durable as poly.
My question is: Can I put Minwax Poly directly over the Tung oil? If so fine. But if not I’ll live with the Tung oil rather than strip again and start all over.
PS Thank goodness for the solid wood construction. Other wise I would of had to junk the table. No way could the veneer been reparied.
Lee2
Replies
First, what do you mean by tung oil? Are you referring to real, 100%, pure tung oil or one of the faux "Tung Oil Finishes"?
If it is pure tung oil, you should let it fully dry for a couple of weeks. Pure tung oil is a very slow drying oil. If it is one of the non-tung oil "Tung Oil Finishes", then you can overcoat it when it has dried a couple of days.
I just finished my reloading bench with varnish over tung oil. I had to wait 8 days before I could put the varnish over the tung. I wiped the surface every day after the last coat of tung, until I didn't get any oil back on my rag. Then I waited another day to put the varnish on it. I finished the top with RockHard Table Top Varnish and love it. You might think about it. It doesn't scratch easy, is...well...rock hard...didn't see that one coming, did you? LOL!! Just my .02
Howie and Urbanredneck: Thanks for your imput. Obviously what I am using called tung oil is different than what you have in mind. The package is labeled tung oil and it is by Minwax. This stuff dries hard in 12 hours and is obviously not like a true oil or something like Watco. I started using tung oil since Nakagima in his book says he uses tung oil with 5 coats. I have seen some of his furniture and the finish looks great. From your imput a poly finish over tung oil after it has completly dried sounds like it will be OK
My curiosity is now aroused about a true tung oil. Any ideas on where it is available? Lee2
You can get real tung oil at some of the better woodworking suppliers; homesteadfinishing might have it too. However, understand that tung oil comes in many forms, and there's no great reason to use "pure" tung oil in its native state, especially since it dries so slowly. A good alkyd varnish will be made from tung oil, but has been treated to dry hard and fast. And what's more, its finish is every bit as good as tung oil.
Personally, I use a homemade brew of half oil (tung, or if I'm not thinking, BLO), half alkyd varnish, and half mineral spirits. The third half is used only for the initial coats, after that I wean down on the spirits. I also will add a Tb of Japan driers to a gallon of my mix to help it cure more. 5-10 coats of it and the finish is great.
I can't wait for my new FWW issue to arrive to check out the article on wipe on finishes. I suspect it will say that Formby's and Minwax "tung oil" finishes, and even Watco are expensive compared to a home brew like the one I use, and no better at bringing out the beauty of the wood.Recommending the use of "Hide Signatures" option under "My Preferences" since 2005
I buy my tung oil from Woodcraft, IIRC. It is 100% pure tung oil, nothing else.
HTH
Lee, here is some info that might be of interest. Minwax Tung Oil Finish does not contain any real tung oil. It is a linseed oil based product.
There are two "true" oils used in finishing. One is linseed oil which comes from flax seeds. The second is tung oil Which comes from a nut tree that originally grew in China. Both are called drying oils although neither really fully dries and becomes hard. The primary use of both is in manufacturing oil based finishes.
A product that is a true tung oil will have a label that says either "pure" or "100%". If it doesn't say that on the label, IT ISN'T TRUE TUNG OIL. Forget about all the other baloney and look for one of those two words if you want to use a true tung oil. If the label contains any other chemicals, except a thinner, you are not getting a true tung oil. Real tung oil has acquired a cachet in the past twenty years that seems to elevate it to some type of magic potion. In fact, as a finish is does not offer anything much different than linseed oil. In spite of the hype, is not significantly more water resistant than linseed oil--both are lousy--nor is it any more durable. Used alone both are fairly inferior "finishes". About the only difference is that tung oil is slightly less amber than linseed oil but it also is slightly less effective at "popping" the grain. By most measures, it is not significantly different from linseed oil.
"Tung Oil Finish" is a marketing expression for products that the manufacturer thinks will give you a finish like the finish you get from a true tung oil. These "Tung Oil Finishes" may or may not contain some true tung oil, but most do not contain any true tung oil. Their only claim to the use of the word "tung" is that it claims to give you the appearence of finish that results from tung oil. You're buying a "faux tung oil finish".
There are two types of "tung oil finishes". One is mixture of varnish, boiled linseed oil and mineral spirits (called an oil/varnish). The exact mixtures are proprietary but 1/3, 1/3, and 1/3 will get you real close. Some manufacturers add a dollop of drier to speed up the drying. This same mixture is frequently also called "Danish Oil" because it gives a finish that resembles the finish used on much of the "danish style" teak furniture imported in the 50's and 60's. It closely mimics a true oil finish but the addition of the varnish resins gives it more durability and protection. These finishes do not need to be overcoated with a film finish. When you do so, you are destroying the look and feel of the finish.
Here are some oil/varnish mixtures:(*)Deft Danish OilGeneral Finishes' SealacellBehlen Danish Oil Maloof FinishBehr Scandinavian Tung Oil FinishMinwax Tung Oil FinishMinwax Antique Oil FinishVelvit OilWatco Danish OilLiberon Finishing Oil ((contains pure tung oil and linseed oil)McCloskey Tung Oil Finish (contains pure tung oil, no linseed oil)
The second "tung oil finish" is one made from varnish and mineral spirits. The approximate ratio is 1:1. This is really just a thinned varnish just like the stuff sold as "wiping varnish". When one two or three coats are applied, it also mimics the finish produced by a true oil but it is harder than the oil/varnish above because it does not have as much oil. It is slightly more protective than the oil/varnish type or tung oil finish. For all intents and purposes it is a varnish finish.
Here are some thinned varnishes:(*)Minway Wiping VarnishWatco Wiping VarnishFormby's Tung Oil FinishZar Wipe-on Tung OilVal-OilHope's Tung Oil VarnishGillespie Tung OilWaterlox Original Sealer/FinishGeneral Finishes' Arm R SealJasco Tung Oil (*) Courtesy Bob Flexner and some personal information.
One way to tell whether the product is an oil/varnish or a wiping varnish is to read the application instuctions. Oil/varnishes are applied, then given some time to set, then wiped dry. Wiping varnish products are wiped on an left to dry (no wiping off).
Finally, I'm not disparaging any of these products. In fact, they are a more protective and durable finish than any pure oil finish. They are what they are and can give you a very nice close-to-the-wood finish when properly applied and not overcoated with a film finish. Howie.........
Howie, a recycled post, but a good one non-the-less.Thanks for reposting.FYI, I'm fond of a few applications of BLO followed by a good urethane varnish - easy to do, pretty, and durable...Mark
Measure it with a micrometer, mark it with chalk, cut it with an ax.
Howie: Great post and really informative. Thanks. I'll put it to good use. Lee2
Howard,
Your explanation of the different products is very helpful but I am hoping you can add some information reguarding using poly over tung oil. You hear so much about "poping" the figure with pure thinned tung oil and what a beautful figure it produces but most experts seem to feel it is not a good finish for a dining table. What do you think about poly over tung for a dining table? Plus and minus? Best wipe ons for a dining table?
Many Thanks, Gordon S. Davis
>> You hear so much about "poping" the figure with pure thinned tung oil and what a beautful figure it produces but most experts seem to feel it is not a good finish for a dining table. What do you think about poly over tung for a dining table? Plus and minus? Best wipe ons for a dining table?
Big question.
First, there is very little difference with "grain poping" whether you use boiled linseed oil or pure, real tung oil. Both will give very similar results. For the very, very observent, tung oil is slightly less amber and ambers slightly less over time. But, the difference is minimal. Test the two out on some of your own scrap to see what I mean.
The fact is, that neither oil is a good finish. I consider both to be a coloring, figure enhancing treatment. Neither has much water or water vapor resistance and neither offers any surface abrasion resistance. Both need to be periodically re-applied to maintain their appearence. That's the reason that neither is recommended for a tabletop that will get any use.
To add protection, a film finish is in order. You can use shellac, laquer, a waterborne finish or an oil based finish. Shellac tends to be a little too tender and susceptable to chemical penetration. Lacquer makes a nice finish but it must be protected from abrasion. Waterborne finishes have about the same durability as lacquer and can be damaged by cleaning chemicals. Lacquer and waterborne is best sprayed. Most commercial tabletops are finished with lacquer. Oil based, non-poly varnish gives what I consider to be the best mix of durability and protection. Poly varnish tend to appear cloudy when built to more than two coats and, except for everyday kitchen tables or floors, I try to avoid it.
Unless you are experienced at brushing varnish, I recommend thinning a non-poly varnish 50/50 with mineral spirits to make a wiping varnish.
Here is something that should help. A friend of mine put it together years ago and it has worked well for many.
QUOTE
There are a number of suggested application regimens that are totally subjective. The number of coats in a given day, the % of cut on various coats, which coat to sand after, when to use the blade and a whole host of other practices are all minor differences between finishers. There are some things that I consider sacred when applying a wipe-on finish.
If you are making your own wipe-on the mix is scientific - thin. I suggest 50/50 with mineral spirits because it is easier to type than any other ratio and easy to remember.
The number of coats in a given day is not important. Important is to apply a wet coat with an applicator and merely get it on. Think of a 16 year old kid working as a busboy at Denny's you have sent over to wipe off a table. The applicator should be wet but not soaked. The applicator can be a paper towel, half a T-shirt sleeve or that one sock left after a load of washing. Then leave it alone. The surface should not be glossy or wet looking. If you have missed a spot, ignore it - you will get it on the next coat. If you try and fix a missed spot you will leave a mark in the finish.
Timing for a second coat involves the pinkie test. Touch the surface with your pinkie. If nothing comes off you are ready for another coat. If was tacky 5 minutes ago but not now, apply your next coat just as you applied the previous coat. Remember, you are wet wiping not flooding. After applying the second coat, let it fully dry for 48 hours. Using 320 paper and a sanding block ligthtly sand the surface flat. Now, begin applying more coats. Do not sand between coats unless you have allowed more than 24 hours to elapse since the prior coat. The number of coats is not critical - there is no critical or right number to apply. For those who need a rule, four more coats on non-critical surfaces or six more coats on surfaces that will get abraded seems to work.
After your last coat has dried at least over night you will have boogers in the surface. You should not have marks in the surface because you ignored application flaws. You may have dust, lint and, if you live in Texas, bug legs. Use a utility knife blade at this point. Hold it between your thumb and forefinger, near the vertical, and gently scrape the surface. Gentle is the important word - no harder than you would scrape your face. If you start scraping aggressively you will leave small cut marks in the surface. After you have scraped to the baby butt stage gently abrade the surface with 320 dry paper or a gray ScotchBrite. Clean off the surface. Now, leave the area for two hours and change your clothes. Apply your last coat with a bit more care than the previous coats and walk away.
An anal person is going to have a tough time with this process. Missed spots have to be ignored. Wet wipe, don't flood. Scraping to babies butt smooth means scraping no harder than scraping a babies butt. Ignoring any of these will leave marks that are tough to get out. Getting these marks out requires some agressive sanding to flatten out the surface and starting over.
Jim Kull
END QUOTE
Finally, It works better to use a gloss varnish for all coats except the last. The flatteners in semi-gloss and satin tend to rapidly fall out of suspension when the finish is highly thinned. If you want a non-gloss finish, use it only on the final coat or two and be sure to stir the material frequently or you will end up with cloudy streaks.Howie.........
Howard,
Many thanks for your effort. This was a real treat to get this help.
Sincerely, Gordon Davis
If your going to use an oil based product as top coat there really is no need to apply any oil before you apply poly.
I had read that the tung oil would bring out the figure better than just adding the poly? Any experience with these two products using the tung oil for figure and poly on top for dining table protection? Many thanks for you help, Gordon Davis
The oil will make a very minor enhancement of the grain, compared to a oil-based varnish by itself, that will be largely thrown away by the use of poly on top. Polyurethane varnish tends to be a little cloudy so that by the time you have applied a film sufficient to be protective you have added a subtle haze. If you substitute a traditional resin varnish, such as Behlen Rockhard or Pratt & Lambert 38 you will end up with a clearer finish that will offer nearly the same level of protection as a polyurethane varnish.
Thanks so much! One last question and that is can you dilute these products and use as a wipe on finish? Any experience? Thanks again, Gordon Davis
Sure thing. The usually recommended dilution is 50-50 though there is nothing at all critical with this. You might give it a try with less thinner. If that works well for you it will build a little faster and require fewer coats. If it seems uncomfortabe to apply, just add more thinner.
Steve,
Many thanks! I needed a confidence builder before this big finishing job.
Gordon Davis
I'm in the process of applying Formby's Tung Oil Finish to an MDF surface. I started out doing the wet wiping and while waiting for a coat to dry I read an article about brushing it on to get a 'build'. I am also planning to apply MINWAX wipe on polyurethane as the final coat (I'm not using the brush on poly to hopefully avoid leveling problems, etc....been through this before). I called MINWAX, who also owns Formby's and asked about the poly over the Tung. The tech support person said that I should let the final Tung coat dry for 30 days before applying the poly. In your experience is this length of time necessary? Also. is my finishing plan good?
Thank You
Thirty days sure seems a bit conservative to apply one oil based varnish over another oil based varnish. That looks like a CYA answer by someone who didn't have a clue.
What need does the polyurethane varnish fill? Formby's Tung Oil Finish is a varnish, not a oil/varnish mix. By itself it offers virtually the same protection as the Minwax varnish, and is probably a bit harder. The Minwax varnish resists abrasion a bit better, so if this project is going to be walked on go ahead with the polyurethane varnish.
However, one coat of polyurethane wipe on varnish doesn't do a thing as far as durability is concerned. It takes at least three coats of wipe on varnish to be equivalent to one coat of brushed on varnish.
Edited 2/8/2007 4:42 pm ET by SteveSchoene
I'm finishing a router table with an MDF surface. I read an article by Pat Warner and saw a mag picture of his router table that was just MDF with a Formby's Tung/Poly finish. I assumed that the Tung part was Formby's Tung Oil Finish and the Poly was Polyurethane. Or is the wipe on (thinned down version of the brush on Poly) the same as the Formby's? Or am I still confused? (I suppose I could just read the labels on the containers). I've applied a few coats of the Formby's and it's starting to build a sheen. Also, I was going to use the wipe on Poly to avoid leveling problems (that's what the advertising indicates) rather than the brush on poly.
It's not furniture, just a router table work surface that will be having wood slid across it.
Check out Zinser's Shellac/Sealer (non-wax version); it makes a great intermediate adhesive finish (i.e. will bond to the oil below and the urethane above). I had good luck with it putting urethane on a linseed oil finished cherry (kitchen) table.
Jimmie, go back and read Howie's earlier post. You are NOT using tung oil if you are applying Minwax's Tung Oil Finish. It's a thinned varnish with boiled linseed oil added. You will find a similar concoction labeled "Danish Oil."http://www.popularwoodworking.com/features/finish2.html
Edited 2/8/2007 5:45 pm ET by byhammerandhand
I didn't see Sutherland Welles Polymerized Tung Oil in the list of finishes on the link provided. What is in it? The labels do not list any additives.
You are applying the same thing under two different labels. They are both wipe on polys.Gretchen
I don't think the Formby's contains polyurethane but is a traditional resin varnish, which in my mind makes it more attractive for furniture. Formby's even calls it a varnish straight out now instead of making people think it was actually tung oil. The point is the same--why put one varnish over another?
Hello Gretchen,
I read the Popular Woodworking article explaing varnishes oil/varnish mixes, etc.
The article says that Formby's Tung Oil Finish is a wiping varnish (will dry to a hard finish) and that Minwax Tung Oil finish is an oil/varnish mix (will dry to a soft finish).
Is Minwax poly really the same as the Formby's? I called Minwax and they own both labels.
The Minwax Tung Oil Finish is more like Watco or for that matter Minwax Antique Oil both being oil/varnish mixes suitable for "in-the-wood" finishes, not built up films. The Formby's Tung Oil Finish and the Minwax Wipe on Poly are both varnishes with somewhat different resin that can both be allowed to build a film on the surface.
The naming and information provided by the manufacturers of consumer based finishes is disgraceful. Tung Oil Finish as no specific meaning across manufacturers. Often you have to read very, very carefully to determine what type of product you are dealing with.
Thank You for the clarification.
Here is some info that may help understanding what finish is what.There are two "true" oils used in finishing. One is linseed oil which is pressed from flax seeds. The second is tung oil Which comes from a nut tree that originally grew in China. Both are called drying oils although neither really fully dries and becomes hard. The primary use of both is in manufacturing oil based finishes.A product that is a true tung oil will have a label that says either "pure" or "100%". If it doesn't say that on the label, IT ISN'T TRUE TUNG OIL. Forget about all the other baloney and look for one of those two words if you want to use a true tung oil. If the label contains any other chemicals, except a thinner, you are not getting a true tung oil. Real tung oil has acquired a cachet in the past twenty years that seems to elevate it to some type of magic potion. In fact, as a finish, it does not offer anything much different than linseed oil. In spite of the hype, is not significantly more water resistant than linseed oil--both are lousy--nor is it any more durable. Used alone both are fairly inferior "finishes". About the only difference is that tung oil is slightly less amber than linseed oil but it also is slightly less effective at "popping" the grain. By most measures, it is not significantly different from linseed oil."Tung Oil Finish" is a marketing expression for products that the manufacturer thinks will give you a finish like the finish you get from a true tung oil. These "Tung Oil Finishes" may or may not contain some true tung oil, but most do not contain any true tung oil. Their only claim to the use of the word "tung" is that it claims to give you the appearence of finish that results from true tung oil. You're buying a "faux tung oil finish".There are two types of "tung oil finishes". One is mixture of varnish, boiled linseed oil and mineral spirits (called an oil/varnish). The exact mixtures are proprietary but 1/3, 1/3, and 1/3 will get you real close. Some manufacturers add a dollop of drier to speed up the drying. This same mixture is frequently also called "Danish Oil" because it gives a finish that resembles the finish used on much of the "danish style" teak furniture imported in the 50's and 60's. It closely mimics a true oil finish but the addition of the varnish resins gives it more durability and protective qualities. These finishes do not need to be overcoated with a film finish. When you do so, you are destroying the look and feel of the finish. Here are some oil/varnish mixtures:(*)
Deft Danish Oil
General Finishes' Seal-A-Cel
Behlen Danish Oil
Maloof Finish (contains pure tung oil and linseed oil)
Behr Scandinavian Tung Oil Finish
Minwax Tung Oil Finish
Minwax Antique Oil Finish
Velvit Oil
Watco Danish Oil
Liberon Finishing Oil ((contains pure tung oil and linseed oil)
McCloskey Tung Oil Finish (contains pure tung oil, no linseed oil)The second "tung oil finish" is one made from varnish and mineral spirits. The approximate ratio is 1:1. This is really just a thinned varnish just like the stuff sold as "wiping varnish". When one two or three coats are applied, it also mimics the finish produced by a true oil but it is harder than the oil/varnish above because it does not have as much oil. It is slightly more protective than the oil/varnish type or tung oil finish. For all intents and purposes it is a varnish finish.Here are some thinned varnishes:(*)
Minway Wiping Varnish
Watco Wiping Varnish
Formby's Tung Oil Finish
Zar Wipe-on Tung Oil
Val-Oil
Hope's Tung Oil Varnish
Gillespie Tung Oil
Waterlox Original Sealer/Finish
General Finishes' Arm-R-Seal
Jasco Tung Oil
(*) Courtesy Bob Flexner and some personal information.One way to tell whether the product is an oil/varnish or a wiping varnish is to read the application instuctions. Oil/varnishes are applied, then given some time to set, then wiped dry. Wiping varnish products are wiped on an left to dry (no wiping off).Finally, I'm not disparaging any of these products. In fact, they are a more protective and durable finish than any pure oil finish. They are what they are and can give you a very nice close-to-the-wood finish when properly applied and not overcoated with a film finish.Howie.........
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