Tung, varnish, and mineral spirits

[Jay Windley]

Hello all,

I decided to try a little of the homebrew I've seen mentioned here: oil-based varnish, tung oil, and mineral spirits in equal proportions. I mixed some up and wiped it on a scrap of pine and a scrap of oak. It seems to be taking forever to dry, is this normal?

Call me impatient, but I put it on about four hours ago and it's not even tacky yet -- still slippery and oily. Keep in mind I live in Utah where any moisture in the air is strictly accidental, and it's been at about 65 F in the shop all evening. Good ventilation.

So have I done something incorrect? Or is this just the nature of the beast? I'm planning to refinish my kitchen cabinets with this concoction and I'd like to get it right before I try. Thanks.

--Jay

[Andy Dingley]

What's the "tung oil" ? If this is pure tung, rather than a blended finishing oil with driers in it, then it's slow to cure anyway. Mixing varnish in there makes it even slower. Warmth and air movement will help. As always for tung, you have to apply it very thinly. Athick coat skins over and doesn't allow the underlying layer to cure.

Personally I wouldn't use white spirit. It's slow to evaporate and leaves an oily residue. I'd favour turpentine instead.

I also think that equal parts in a varnish/oil mix is too much varnish. I don't use more than about 1/4.

To be honest, I very rarely mix my own oil mixtures. Commercial mxes are good and cost no more than the ingredients. I fool around recreating old spirit varnishes from raw sandarac or copal, but for oils I'm happy enough with off-the-shelf.

-- Congrats to STBL on his elevation from TLA to ETLA

[Al Martin]

You did not say whether or not you wiped the excess off....at those proportions even if you wiped the excess you should allow about 2 days drying time. I use approx. 1/3 turps, 1/3 boiled linseed oil, 1/3 minwax spar varnish....leaning a little heavy with the turps.......use a brush and heavily coat the object....wait about 1/2 hour, depending on the density of the wood....if you see drying spots, start wiping then. After the 1/2 hour wipe with a clean old towel, do every inch as any spots you miss will remain wet/tacky for up to a week. Hope this helps.

[Jeff Fleisher]

I watch David Marks on 'Wood Works' and he uses a Tung Oil finish. I've tried it and love it. Per directions on the bottle of 'pure' tung oil that I bought at Woodcraft.....I mix 50% tung oil and 50% paint thinner (less smelly than turpentine) and apply with either a brush or rag. Then wipe off excess wtih a dry rag. It dries in about an hour and a new coat can be applied. Dries supper smooth and gives a wonderfull finish. Jeff

[Jay Windley]

Ah. It's 100% tung with no driers. Reading your response and Al Martin's I think I have a much better understanding, thanks. I've thought of it as having added tung and mineral spirits to varnish. I've used varnish technique and have varnish expectations. I suppose I need to be thinking about it as having added varnish to tung, and therefore I need to be using tung technique and need to evaluate the results using tung expectations.

No, I did not wipe off the excess because I thought I was applying varnish in which tung had been added, not tung in which varnish had been added. But since I wiped it on, it went on thin anyway. No great loss here, as I'm still working on scrap. I can see how this particular mix works when applied as you've suggested.

| Personally I wouldn't use white spirit. It's slow to evaporate and | leaves an oily residue. I'd favour turpentine instead.

I plan to experiment with solvents to see which works best for me. I have a surplus of mineral spirits and so that's where I started.

| I also think that equal parts in a varnish/oil mix is too much | varnish. I don't use more than about 1/4.

More oil, less varnish -- got it. I've seen lots of formulas posted here and elsewhere, but equal proportions sounded like a good place to start.

| To be honest, I very rarely mix my own oil mixtures. Commercial | mixes are good and cost no more than the ingredients.

I have several of the commercial mixes and I find them quite acceptable. The exercise here is more experimentation than production. Even if I end up putting something entirely different on my kitchen cabinets, I'm using this as an excuse to learn more about this particular mix.

--Jay

[Anthony Diodati]