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:
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!...