Tung oil won't dry...

[Golf Vergnugen]

I purchased Woodcrafts 100% pure Tung Oil and have applied a couple coats but it seems that the stuff just won't dry fully. The label says that you wait at least an hour between coats, which to me suggests it should dry quickly.

Should I have cut it with something that helps it to harden? I used mineral spirits as recommended in the directions (1/1) and waited overnight between coats too.

Is there anything I can put over it now without causing more problems?

[george wilson]

Tung oil takes 4 or 5 days at least to dry. If it is cold,it probably slows it down. We used it all the time on our wooden tools,because mould doesn't grow on it. We were using exactly the same product as you. It's not as fast as Linseed oil.

They probably want you to wait to recoat because it gives time for the oil to sink into the wood,so it can take more.

[Joe Cunningham]

Did you wide off the excess after 1/2 an hour or so? You don't just leave it on the surface, it will take forever to dry that way and look horrible to boot.

[John Thompson]

Agree with George and Joe. Linseed and tung take a a while to dry with tung taking the longest. If you are using it for furniture.. I follow a reginment. I apply early day and wipe it clean about every hour for the first four.. then ever two hours for the next four hours. Then wipe it the following morning and during the day as needed.

The oil penetrates the pores and will keeping coming to the surface until fully cured. You can wipe it and see little beads appear again in 30 minutes at first.. hence the frequent wiping. If you don't wipe them... they will dry and the finish looks like well... litte beads of oil.

So... now you know about oil times and BTW... I let linseed sit a week to cure before appling wax.. I let tung sit two weeks before applying wax and one reason I really don't lile using pure tung oil.

Good luck and be patient...

Sarge..

[Terry Beadle]

Try a 1:4 ( 1 part Japan Dryer ) in a small batch of Tung Oil and apply to a scrap. That should give you much quicker drying time.

[george wilson]

We used to just saturate the wood with tung oil,usually beechwood tools. It always completely sank into the wood due to its long drying time. I'm not even saying the tung oil would be dry in 5 days,but it would be sunken in enough to handle by then. I'd wait some weeks before putting anything on over it. At least,you won't find green mildew growing on your projects. Some of our end users kept their tools in unheated places. That's why we went to tung oil rather than linseed oil,which would support mildew.

[Frederick Rowe]

Golf - You didn't mention what the temperature was in your shop. But, like George said, unless it was an oven, I've never heard of any oil (without an additive such as Japan Dryer) setting in less than 12-24 hours. Applying a Japan Dryer now won't help. Might try Naptha to remove the uncured Tung oil.

[Bill Wyko]

I apply a coat then whipe it off in about 5 minutes. Then I let it sit for 24 hours and go over it with 0000 steel wool. Then repeat about 4 or 5 times. It takes time but it's worth the results. Definitely not for production. Here's what it looks like when I'm 3 coats into it.

[John Eaton]

The other thing when using finishes is to make sure there's air movement - if it's in an enclosed space it'll take forever to dry - the solvents gas out and just sit on the sureface above the oil. That's why oil-based finishes usually dry faster outside - it's the air flow.

-- John

[Bill Wyko]

I agree. I leave 2 fans on most of the time. Tung oil is a fantastic look and feel when you take the time. I thought I'd add, I use a vacuum clamp to hold small projects and it makes it much easier.

[Bill Wyko]

I use Minwax which has about 45% Tung oil but I couldn't tell you what the rest is. Works great though and never had a drying issue.

[Joe Cunningham]

Minwax Tung Oil is really a danish oil (mix of oil, varnish and thinner), which if I recall correctly doesn't even contain tung oil, but instead has linseed oil. It is a much easier product to finish with than pure tung oil.

100% tung oil is a different animal and more akin to raw linseed oil. I doubt many people have used it as a complete finish--I often use it to 'oil' milk paint. And even then I just put it on and wiped it off within 15 minutes or so. When I've put on as a part of a finishing schedule (oil, shellac, then varnish) I also always wiped it off after 15-20 minutes. And usually let it cure for a week before I put on the shellac. Because it doesn't have the metallic dries like BLO, it takes longer to cure, though not nearly as long as raw linseed oil as I understand it.

About the only reason I use it is when I really don't want the oil to add much color to the finish. Boiled linseed oil tends to yellow.

[Howard Acheson]

Actually, oil based finishes dry/cure in two steps. The first step is the evaporation of the thinner/solvents. Once they have evaporated, the surface is no longer tacky but the film has not hardened. The second step is the interaction of the varnish with oxygen. This oxidizing is what creates a hard, well adhered and durable finish. This second process can take 3-4 weeks to complete depending on temperature primarily. As long as you can smell the finish, it it still outgassing and curing.

The long curing process is why one should wait for 3-4 weeks before waxing or attempting to rub out the finish.

[Peter Quinn]

Yup, pure tung oil can take a long time to dry. I restored a hand rail and newel post some time back and used pure tung oil for the finish. First coat, 3 parts oil to one part mineral spirits, took 48 hours to tack up but I wouldn't call it dry by any means. I tried a few different formulas and wound up adding japan dryer, mineral spirits, a bit of varnish, several fans for circulation, got the dry time down to 18 hours, but it took way more coats being so thinned out it seemed. Does look handsome when its all done, not a real production product though.

[Doug Hobkirk]

I apply a coat then whipe it off in about 5 minutes. Then I let it sit for 24 hours and go over it with 0000 steel wool. Then repeat about 4 or 5 times. It takes time but it's worth the results. Definitely not for production. Here's what it looks like when I'm 3 coats into it.

Such a show off!
PS - ABSOLUTELY gorgeous! I am sure there are people who don't want more than one type of wood in a project, but that isn't me - I love the variety and contrasts.
PPS - FWW is having a "box" contest.