Thinning Tung Oil?

[Kevin Gerstenecker]

I "Inherited" a quart of Tung Oil from a neighbor today. It is a little thick, because it has been sitting around a while. Is it possible to thin the Tung Oil with something, like Mineral Spirits, to make it usable? It can probably be used as is, but the viscosity is about like Motor Oil. If I can salvage it, I would like to do so. He said he bought it about a year ago, and use a little to protect a small table he refinished. Just wondering if this could be saved. Thanks in advance for any and all help! ;)

[Jim Becker]

Old finishes are trouble looking for a chance to happen...while it was nice that your neighbor thought of you, it's probably not worth trying to salvage this oil. The rule of thumb for oil and oil-based finishes is only buy what you can use relatively immediately and discard any leftovers after a couple of months. The second you expose them to oxygen, they begin to cure even in the can. Old finishes also tend to "not dry"...bad news for your projects!

[Jim DeLaney]

I "Inherited" a quart of Tung Oil from a neighbor today.

Assuming pure tung oil, and not a varnish mix, it should be okay to use, and can be thinned with naphtha. I've got some that's over ten years old, and still as good as new.

YMMV.

[Steven Wilson]

Well, try some of the Tung Oil on a piece of scrap Cherry and see if it cures. If it does then you might consider placing in into a plastic container that you can squeze the air out of or place marbles in its current container to fill it up. As for a thinner I like to use Turpentine (pure gum spirits of.... not the fake stuff) for Tung and/or BLO.

[Howard Acheson]

As Jim has said, pure, 100% tung oil never really goes bad. It is a thick, syrupy consistancy in it's normal state.

You can thin it with either mineral spirits or naphtha. But, nothing will speed up its cure rate. Tung oil can take months to fully cure unless it is put on very thin and wiped dry. Even then, a month or more is not unusual.