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Shellac over wipe on poly?

Hm not sure about that. The other way around is no problem but not sure about shellac on top. Why would you want to do that. Shellac is not as water resistance or abrasion resistant.
 
john lucas said:
Hm not sure about that. The other way around is no problem but not sure about shellac on top. Why would you want to do that. Shellac is not as water resistance or abrasion resistant.
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Thanks for the reply. I have put on several coats of wipe on poly and thought shellac might cover faster. I did not know it it not bear up as well as wipe on poly. I'll just stick with the W/P and keep recoating
Thanks.
 
The shellac will stick to the poly just fine, shellac will stick to almost anything. The problem is, poly is a rather soft/flexible material, while the shellac is hard/inflexible. As the poly moves the rigid shellac on top can't move as much and will crack over time.

BTW, if using shellac under another finish, make sure it is un-waxed.
 
Tim you said to make sure the shellac is un-waxed. I have always heard that and wondered what difference it makes. Where I live dewaxed shellac is pretty much a thing of the past. So I have used the waxed version,though it doesn't say it has wax in it, it just doesn't say it's de-waxed. I have used it interchangeably and have no problem. I mix it with alcohol sometimes and use it for sanding sealer to stiffen the fuzzies and to seal it to vacuum chuck.
 
Fred, I've never experimented, just going by what I've read in a couple of books, and the primary issue would be with oil based poly or water based finishes applied over waxed shellac. Recently, your experience and that of others I've read online counter that argument.

Could guess on several different reasons, but don't really know why your results differ from what I've read.

Here is a short article on the differences between Zinsser Seal Coat shellac (dewaxed) and the regular Shellac. https://www.finewoodworking.com/2014/10/01/seal-your-project-with-dewaxed-shellac

BTW, I've never used either Zinsser product, I mix my own from dewaxed flakes.
 
Finish will not adhere properly to waxed shellac so that is why always say use dewaxed . Waxed is fine as a topcoat but you cannot add another finish over it and get a good surface.
Shellac is universal and can be used under or over any finish but as stated may not be the best for some finishes.
 
I should add that even the super blonde shellac flakes still have a surprisingly large amount of wax. Therefore, I filter it and have to change filters frequently because it doesn't take long before they are clogged with wax.
 
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