View Full Version : Can you use shallac under poly?

Michael Pfau
07-09-2005, 10:25 PM
I have used shallac under poly before (simply because it drys so quickly) and have never had a problem, how come on the side of the can of Zinssers shellac it says not recommended under poly? any ideas?...I believe all Zinsser shallac is dewaxed, not sure if this means anything..need help!

Steven Wilson
07-10-2005, 12:03 AM
Zinsser sealcoat is dewaxed, all the other Zinsser shellac has wax in it. If you're going to use shellac as a base coat, seal coat, or color coat then use the dewaxed variety.

Jim Becker
07-10-2005, 9:27 AM
Steven has the answer. Poly doesn't like to stick to itself...which is why light abrasion is required between coats after a few hours have passed. Shellac with wax would just cause the poly to flake or chip off easily. Unless I'm specifically using shellac as the finish, I stick with dewaxed flakes or pre-mixed, such as the Zissner Sealcoat.

Please note that you can use shellac with wax under alkyd or phenolic varnishes...just not under polyurethane varnishes. But sticking with de-waxed is the best bet and easier, IMHO. You only have one kind of product around the shop. I also suggest you consider mixing your own from flakes. Not only do you get more color/tone options, but flakes have virtually unlimited shelf life. Not so for anything mixed...

Pete Salvatore
07-12-2005, 9:50 AM
I just went through this also. However, I believe that if you use a home made mix of pure varnish (nothing with poly) and mineral spirits (to make a wipe on varnish) then either shellac can be used. I personally will use the de-waxed in the future.