Hi,
Weekend before last (ie Sunday 24th) I applied tung oil to plywood (simply described as “12mm hardwood plywood” by the DIY shop). One week and a bit later, it looks dry to the eye, there is no shiny spot, the wood has a warmer colour, but if I run my fingers on the surface I get a tiny amount of oil.
I applied the oil by pouring a small amount on the surface of the wood then rubbing with an old rag, leaving no pool of oil.
Sunday (the day before yesterday ) I used kitchen towels to try to dry it off. The towels picked up a tiny bit of oil, but evidently not everything.
Is tung oil that slow to dry? Should I wait another week? Can I do something to help the process along? (Sanding or steel wool? Too aggressive for the thin veneer of plywood? Rub with a small amount of white spirit? )
I’m making a crate for Puppy who has outgrown two crates already, I picked the oil that was advertised as food & toy safe without realising how difficult it’d be to apply. In fact that’s my most ambitious project to date, I’m really a beginner.
Puppy tax:
In my experience, tung oil can take up to a month to fully cure.
If you used pure tung oil, then it will likely take that long. Cutting it with orange oil can help a bit next time.
The only thing you can do now to speed it up is to keep it somewhere warm. However, it has probably cured enough that you could start using it now. Just give it another wipe down.
It is pure oil, maybe I’m being too impatient then, a month is a long time though!
/u/NataliePortland@lemmy.ca suggested a wipe with solvent, is that the role of orange oil? I think ill try that when I have time in few days
That is a month to fully cure. It should be dry to the touch before then, though that can still take weeks at worst. Keep it in a warmer and dryer place if you can as that will speed it up.
Yes, orange oil is a solvent. It has other uses as a natural solvent and it smells great! Handy to have around the house regardless.
Hmm I wonder if your project has been stored in room temperature or was it outside in the cold?
I might use a solvent to wipe it down, with a light 220 grit sanding, then try again.
I’m also wondering if you might have skipped a step. You should apply the oil, wait 5 minutes or so, then wipe off the excess. Then keep it in room temperature for a day. Repeat three times and then buff or polish.
It’s inside the house, but this being winter, is not super warm.
I disn’t do the two steps apply liberally, wipe the excess a few minutes later. Of well, top late to go back and do that :)
I think I’ll try your suggestion when I have time in a few days
Hmmm, tung oil takes a while to set fully, but I’ve never had it be that “wet” after a week. Not enough to leave residue on touch.
Even if the plywood was treated in a way that made the finish not “stick”, it shouldn’t be leaving oil when touched, it should have just beaded up originally.
I’m not aware of anything that will speed it up though, not significantly. If you’re already keeping the project in a relatively warm environment with good air flow, that’s about as good as it gets. Like, this time of year, if it’s outside, you might expect it to still be a little tacky to the touch, but not oily.
Honestly, I’m baffled why it would be giving up oil to touch at this point. I’ve never run into that, and it’s my preferred finish for my canes and walking sticks, so I’ve used it a good bit since needing them. It’s not a lot of usage, I only need the finish when I either get a new cane/stick, or one gets damaged enough to need refinishing, but I’ve built up a decent sized collection at this point. And it never happened with any of the takes furniture I’ve used it on.
Usually, it’s dry to the touch in a few days at most. Never seen it take more than a week.
You clearly have more experience than I do; the only explanation for why my (one) attempt is not going so well is that I had less than ideal conditions. Both temperature and user technique, probably the latter is most to blame!..
I would cover the whole with shellac which sticks to just about everything, is food safe (they use it in coated medication) if you mix your own (don’t use denatured alcohol - pay the big $$$ for high proof alcohol). This will dry fast and look nice. It isn’t the most durable finish though.
plywood is thin and the glues can chemically react with a finish the soaks in like tung oil does.
