Est. 1998 — 27 years of woodworking knowledge
Finishing Question
Guy A
>This may not be the board to post this question - but I'll give it a shot. I have a project I did over two years ago and I beleive I put a couple of coats of shellac (waxed). I want to finish it and decided to use poly as a finish. Can I seal it with de-waxed shellac then poly? I'm not sure if the poly will bond with regular shellac? My lesson is learned, to never let anything sit this long again.
Thanks Guy
Re: Finishing Question
Steve Wargo
>Scrub it up with a liberal amount of Mineral Spirits to remove the wax. If you're having adhesion problems after that, then remove all the shelac with Denatured alcohol and start over.
Re: Finishing Question
Frank D. in Montreal
>Hi Guy,
If you don't want to strip the shellac that's on the piece already, putting on a few coats of dewaxed before the poly should prevent any adhesion problems. As Steve said, rub it down well with mineral spirits because any wax residue might cause problems (soft spots, separation between layers of finish). I use poly a lot (I do mostly carpentry) and have never had adhesion problems as long as there's a few coats of dewaxed underneath. I use Zinsser's SealCoat, a lot less trouble than mixing flakes when you don't want colour and the cut is just right to wipe or brush. Don't overdo the shellac sealer, though, because it can cause the poly to turn white when dents are made in the finished wood.
Regards,
Frank