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Tung oil question
- Thread starter Alan Weinberg
- Start date
24 hours for pure tung oil is not nearly enough. You need something with metallic driers added if you want that kind of recoat speed.
Adding on to what Richard said, I’ve had the most success with tung oil if I dilute 1:1 for the first coat (or two). Lately I’ve been using naphtha vm&p as my thinner and it’s great. Thinner initial coating allows the tung to penetrate deeply, and cuts down the amount of time needed between coats.
It's uneven because of uneven absorption. I'm guessing that you wiped on a coat and then wiped off a tiny bit of excess later.
Each coat needs to be flooded on and kept wet for 15 -20 minutes or until areas are no longer absorbing the oil. On less dense softwoods they will absorb an incredible amount of oil, particularly on the end grain. Areas with tear out will also absorb large amounts of oil.
I use polymerized tung oil (my own mixture) and will get drying (recoat) in 24 hours. Pure tung oil will take several days to dry.
I would let your piece dry for a week, scuff sand with 400x or so grit and then flood the surface until it won't absorb anymore oil. Wipe it off, let it dry for a week and repeat as necessary to get an even sheen.
Each coat needs to be flooded on and kept wet for 15 -20 minutes or until areas are no longer absorbing the oil. On less dense softwoods they will absorb an incredible amount of oil, particularly on the end grain. Areas with tear out will also absorb large amounts of oil.
I use polymerized tung oil (my own mixture) and will get drying (recoat) in 24 hours. Pure tung oil will take several days to dry.
I would let your piece dry for a week, scuff sand with 400x or so grit and then flood the surface until it won't absorb anymore oil. Wipe it off, let it dry for a week and repeat as necessary to get an even sheen.
I have recently used Citrus solvent (Natures' Orange - orange oil extract) to thin Hope's Pure Tung Oil mixing it about 50/50. It dries quickly and smells like oranges while curing. The citrus solvent appears to do at least 2 things. One, it helps the tung oil dry much more quickly than pure tung oil would. Second, the tung is absorbed into the wood more completely and does not bleed back out. Thinning it might require more coats, but I haven't done more than 5 so far. It gives a nice deep finish with a nice satin finish and really does bring out the grain.
Thanks. I’ve used a premixed tung/citrus from Milk Paint Company with a dark tung oil but got little shine.
Looks like I’m not patient enough between coats and certain areas are absorbing more.
Thanks all.
You can also wet sand with the oil to even it out. This will remove any cured oil off the surface and work some of the slurry it makes into any open pores on the end grain. I like to start at 600 grit and if needed work up to 3000.
Based on your pictures, the wood itself would yield variation in absorption of the tung oil and appearance; knots and the fact that it is pine. I would think it would require more than the normal abount of coats to get an even finish. Depends to some degree also on what your final sanding grit was. I found that 24 hours between coats of tung oil/citrus solvent was more than enough, at least for the first few coats. Pure tung oil, though, would take longer to cure between coats.
Beall buffing of cured tung oil will increase the shine quite a bit.
For future pieces of pine, cedar and similar (resinous wood) shellac is the best. Top coat it if you like, or just the shellac and a bit of wax for a nice shine.
That is what I see too. It is hard to use oil on porous wood and get an even shine. Depending on the wood you may be able to get it to seal with multiple coats. As mentioned tung oil takes a long time to dry if not polymerized. I usually wait at least couple days between coats. A coat or two of shellac before putting on the oil may help seal some of the porosity.
I like this finish a lot. Unlike some film finishes, oil does not take that well to rubbing out using compounds, but the speed of the Beall buff does amazing things to it.
One other tip is after Beall buffing if there are minor variations in the finish shine you can usually remove those by putting on a coat of renaissance wax and hand buffing.
The unevenness is likely due to bleed out and not really getting the surface wiped down well enough initially. Check the pieces after sitting for a few hours, they likely will need another wipe down.
Hi Tim- I would be interested in knowing more about your own Polymerized Tung Oil mixture?
didn’t know about the Beall system but from videos I’ve since watched it seems that one cannot do the inside of a small bowl with that system, just outside, right? Might be worth buying. Thanks.
Will, here is a thread on the Wood Barter site that lists some of my experimentation with customizing my tung oil mix. https://woodbarter.com/threads/review-of-polymerized-tung-oil-from-the-skin-boat-store.43545/
In brief, the mix is 1quart of polymerized tung oil from the Skin Boat store, 1 quart of citrus solvent and 3 oz Japan drier. I've since started using 1.5 oz of Japan drier in the mix and it performs just as well.
I'll note that the source of tung oil is important. Some sell polymerized tung oil (PTO) that is heat treated AND has some driers added. Some sell PTO that is heat treated only. Skin Boat store sells PTO that is only heat treated and took several days to dry under my conditions. The addition of Japan Drier took that down to 1 day.
The cost of making your own mix is about half that of buying a PTO from companies that use a drying agent.
In brief, the mix is 1quart of polymerized tung oil from the Skin Boat store, 1 quart of citrus solvent and 3 oz Japan drier. I've since started using 1.5 oz of Japan drier in the mix and it performs just as well.
I'll note that the source of tung oil is important. Some sell polymerized tung oil (PTO) that is heat treated AND has some driers added. Some sell PTO that is heat treated only. Skin Boat store sells PTO that is only heat treated and took several days to dry under my conditions. The addition of Japan Drier took that down to 1 day.
The cost of making your own mix is about half that of buying a PTO from companies that use a drying agent.
I’m curious why you choose to use tung oil and add japan drier. Typically people will say they use a heat treated oil (tung, linseed, walnut) because it doesnt have the chemicals. Seems box store blo would serve the same purpose as your tung oil mix, and much cheaper.
Tom Gall
TOTW Team
I don't know if they are still available since J. Beall retired - but, 25 yrs. ago I bought a set of 4" Beall buffing wheels. They worked so well I bought 3 drills just so I didn't have to change them out. You will need to make a mandrel for each. I haven't used my large wheels ever since. Advantage: buff the piece while still mounted on the lathe & turning slowly (more control) ... you will never have another piece pulled out of your hand - you'll never have any burn through of the finish - you won't have to wait to wait as long for the finish to cure before buffing. Another option are goblet buffs - downside is the buffing cloths (material) are all the same, unlike the regular buffing set.
Thanks for the link Tim. Very helpful.
I use the tung vs linseed oil for a couple of reasons. First is the color, BLO has much more of an amber color than tung, especially with multiple coats. Tung also provides a more durable finish that is harder and more water resistant than BLO.
As to the chemicals, they are not an issue once cured. I use the citrus solvent because I like the odor of it vs naphtha. Granted, you need to use gloves when handling, but not a big deal.
Woodcraft has 3" Bowl Buffs listed, which is what I use for almost everything. https://www.woodcraft.com/products/beall-3-bowl-buff-set-of-3
I have 8 inch wheels, 4 inch wheels, and 3 inch bowl buffs for each compound, I find all of them useful.
I too am confused by using Japan drier. I though the idea of using polymerized tung is so you don't have to use metallic driers to get faster dry times than pure tung oil?
Pics I have been able to find on the web of tung and linseed oils indicate they are very similar in color. Would it be possible for you to put some of each in a clear container and take a picture side by side with a white background, perhaps taken from above with a 1/4” or so depth of oil? I have not been able to locate this type of “true color comparison”.
With the heat polymerized (no chemical driers) you do get faster drying, but was still taking 5 days vs 2-3 weeks for pure tung oil.
Lee Valley polymerized tung oil dries in 24 hours, but it also contains chemical driers. My mix performs the same as the Lee Valley, but costs half as much ( at the time I posted the thread on Wood Barter).
@Doug Freeman I'll see what I can put together tonight for a couple of pictures.
I agree pure Tung oil takes 2-3 weeks to dry. But I find I can do re-coat in 2-3 days. Note that I am using 50/50 thinned Tung oil, full thickness re-coat is more like 7+ days. I do wait the 2+ weeks before buffing after the last coat. What type of re-coat times are you getting?
I find the Japan drier darkens the finish. I use it sparingly for wipe on poly gloss finishes to minimize darkening.
I recoat in 24 hours and if I'm buffing, will wait a week or more.
Driers do slightly darken the oil vs pure tung, but everything is a tradeoff. If I have something I'm trying to maintain a pure, very light color I'll use lacquer.
Another issue with BLO is that over time it darkens and develops an almost orange tint while tung appears to remain relatively unchanged in color.
Driers do slightly darken the oil vs pure tung, but everything is a tradeoff. If I have something I'm trying to maintain a pure, very light color I'll use lacquer.
Another issue with BLO is that over time it darkens and develops an almost orange tint while tung appears to remain relatively unchanged in color.
That is a lot faster with the driers. I usually re-coat in 3 hours with the poly and drier, different animal, just putting that out there in case anybody is wondering. I am gonna try the drier with pure tung oil and see what happens. Thanks for all the info Tim!
BLO is orange while tung oil is yellow. Yellow tends to go better with lighter colored wood than orange.
@Doug Freeman sorry no comparison pictures. Thought I still had a partial can of BLO, but can't find it anywhere.