# Drying a Tung Oil Finish



## barkinmarmot (Mar 19, 2011)

I'm in the process of finishing a coffee table with tung oil and seem to have an issue. First off - the details. I'm not a pro, just a hobbyist. Using 100% pure tung oil. The first coat I cut to 50/50 with mineral spirits and the wood soaked it right up (the table is made from reclaimed Saal wood). Second coat was applied 4 days later un-thinned. The excess was rubbed off after 15 minutes. After 2 more days it felt relatively dry to the touch so I light sanded with #0000 steel wool and applied the third un-thinned coat. Excess wiped off after 15 minutes. Well now it's 8 days later and the surface does not feel as dry to the touch. If I hold my hand on it for 5 seconds, the warmth seems to pull some oil up out of the wood to where I can see it as a shinier hand print on the surface. I'm guessing maybe the wood has already reached it's saturation point. I was prepared to do many more coats. My plan is to topcoat the table with some poly for extra scratch/gouge protection but my gut tells me not to do that yet with uncured tung oil on there. How do I take care of this? Apply more mineral spirits? Set the top out in the sun (not practical for me really)? Set up a fan and run air over it for weeks? Go ahead and do the poly?? Any advice on how to deal with this would be great!


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## cabinetman (Jul 5, 2007)

Drying time for Tung oil can vary depending on your location, RH, temperature. It takes a while for that stuff to cure. There is no rush fix. You have to let applications dry...it could take several weeks or longer. 

Wiping with a solvent won't do much to make it dry faster. It will just wipe what's on the surface. If you do abrading you might like using a microfiber pad like white 3M Scotchbrite, instead of steel wool.












 







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## jack warner (Oct 15, 2010)

true tung will take 30 days or more between coats at 70 deg. its important to wait till the previous coat is relatively dry. weeping is common frequent wipe downs are needed. you must have alot of pataint's. your better off using fine grit paper than steel wool but wait till dry.


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## barkinmarmot (Mar 19, 2011)

cabinetman said:


> Drying time for Tung oil can vary depending on your location, RH, temperature. It takes a while for that stuff to cure. There is no rush fix. You have to let applications dry...it could take several weeks or longer.
> 
> Wiping with a solvent won't do much to make it dry faster. It will just wipe what's on the surface. If you do abrading you might like using a microfiber pad like white 3M Scotchbrite, instead of steel wool.
> 
> .


I'm in the Midwest. Basement is cool - in the low 50's and fairly low RH. I knew up front that it would take patience but of course, now I'm wanting to get to the poly. So, I'm assuming the last coat has hit saturation and doing another coat (once the current one has dried) of Tung would be useless (grain and color is "popped" enough for me)? Can I do anything to help drying along? I'm bright enough to know better than to use heat :no:
As far as steel wool, you guys are right. Any exposed edges or grain do catch the steel fibers. And I've read that when using water based finishes they can rust and discolor things in time. I'll go with fine grit or the scotchbrites.


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## jack warner (Oct 15, 2010)

i strongly recommend against a poly over tung. poly's dont stick well to it self much less over an oil finish.


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## cabinetman (Jul 5, 2007)

barkinmarmot said:


> I'm in the Midwest. Basement is cool - in the low 50's and fairly low RH. I knew up front that it would take patience but of course, now I'm wanting to get to the poly.


If you let the wood dry out completely, you shouldn't have a problem applying oil base polyurethane. Just don't get too anxious.











 







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## jack warner (Oct 15, 2010)

cabinetman said:


> If you let the wood dry out completely, you shouldn't have a problem applying oil base polyurethane. Just don't get too anxious.
> 
> 
> 
> i disagree. poly requires a 220 or ruffer sanding to stick. sealing the wood with any oil finish will prevent poly from sticking. if you back track and sand your final, CURED, ( not just dry ), oil finish, you might have a little luck. ive learned over the 30 ys of finishing not to mix an oil, tung finish with film finishes. its best to do one or the other.


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## cabinetman (Jul 5, 2007)

jack warner said:


> cabinetman said:
> 
> 
> > If you let the wood dry out completely, you shouldn't have a problem applying oil base polyurethane. Just don't get too anxious.
> ...


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## jack warner (Oct 15, 2010)

both poly's and varnishes dont need additional enhancement, they will make the grain pop on there own. most the time better than any other film finish.


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## barkinmarmot (Mar 19, 2011)

Prior to starting this project I had researched "polyurethane over tung oil" and didn't find any no's no's concerning it other than make sure the tung is DRY (CURED). You guys clearly differ on this and I respect that. I purchased a can of Varathane water-based satin poly. Do I HAVE to use oil-based poly? And why? Prior to oiling I sanded up to 320. Whether using oil-based or water-based poly I was planning on a light sanding before application. I'd love to hear other's experiences with tung oil and poly!


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## jack warner (Oct 15, 2010)

i cant help with the water poly i dont like water finish coats. i personaly wouldnt put a water over oil. 320 is way to fine for a poly


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## Steve Z. (Mar 20, 2011)

I'm new here and wanted to chime in because I had the same question about poly over tung oil. From my research it is completely ok as long as the poly is oil based.

Here are a couple of answers from Rockler:

*A. Michael Dresdner:* "Yes, I would put a coat or two of oil-based polyurethane on for more durability, and it is fully compatible over the dried tung oil (or linseed oil, or any other drying oil for that matter.) In fact, you can apply it in much the same way as you did the oil -- scrub it on with fine Scotchbrite, then wipe it off. That will leave a thin coat that will maintain the look you want with no drips or brush marks. Add at least three coats, at one coat per day. If it starts to wear down the road a few years, add extra coats the same way." 
*A. Lee Grindinger:* "You'll get there eventually if you keep applying the tung oil finish. Tung oil finish is varnish, highly thinned varnish, so your coats are very thin and you'll need very many. If you want a faster build use a regular varnish and brush or spray it on. There are still many varnish formulations that use tung oil. To keep the sheen low use satin or eggshell. Plan on rubbing the surface out with steel wool or rubbing compound to remove the nibs."


Hope that helps. I'm going for it.


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## barkinmarmot (Mar 19, 2011)

An update on this one:
Tung oil is now cured - after almost 4 weeks. I now know that Tung oil takes A LOT of patience. In this case it's ok with me since I don't need to have the table done until June.
The water-based poly is going back to the store and I'm getting oil-based to do a protective topcoat. Since I sanded to 320 before the Tung oil (this may have inhibited the oils absorption somewhat) I am planning on light sanding back to 220 or maybe even 180 to hopefully give the poly some "grip" (as Jack Warner suggests).
I'll update on the results when done, and of course suggestions are always welcome!


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## belwoodny (Aug 15, 2017)

Drying time is the main reason I stick with Waterlox...


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