I've got a question for all you wood finishers.
What I've done so far: I've turned my first project and it happens to be shave brush handle in walnut. I've decided on a pure tung oil finish (from Rockler) since I've never tried it, I want a matte finish, doesn't have fumes, was supposed to be waterproof. First coat was 50/50 mineral spirits to tung. I then rubbed on a light layer of that, let it sit 15 minutes, wiped off any extra and rubbed it in with my hands (as per the instructions). The other three or four coats were straight tung oil. Now, I've let it sit at least a week. I did a quick test of water droplets to see if it was waterproofed and it failed. So I got some Helmsman spray urethane and did two very thin coats. It doesn't seem to be drying. I can literally scrape it off with my palm.

My questions: Can I truly get a waterproof seal with tung oil? Should I let the brush sit in vat of it for a couple days (because maybe my coats were too thin)? Can I put urethane right on top of dried tung oil?

That was a long post. Thank you for reading. As repayment for information I'll post pictures of the handle (and eventually scales).