Can I Poly Over Shellac?

[Derek Arita]

So I've applied an Amber Shellac to some oval boxes, however I don't like the glossy finish. Can I apply apply some polyurethane over the dried shellac?https://i.imgur.com/7OgRUYN.jpg

[Robert Hayward]

I do it quite often, so I will say yes.

I also often knock the gloss off shellac with 600 grit or a little higher then buff it with 0000 steel wool to remove any visible scratches. This is on craft and hobby type projects. Might be too much work on a larger piece. Here are two 1 1/2" or so spheres that were finished that way. leaves a soft sheen.

[Paul F Franklin]

From the Bull's Eye technical data sheet: Bulls-Eye Shellac is not recommended for use as a sealer under polyurethane. This is because Bulls eye shellac is not dewaxed. Another Zinsser product, Bulls Eye Seal Coat, is also shellac but is dewaxed and can be used under poly. As Robert said, you can easily remove the gloss by rubbing out the finish if that's all you don't like about what you have. If you really want to add Poly, you can put on a sealer coat of Seal Coat and then poly.

[Tom Bussey]

It must be dewaxed shellac, so I wouldn't do it with the shellac you show. Zinsser does make a sealer for this reason, it is called seal coat and it is a sanding sealer that is quarantined to be compatible with any top coat. Water based top coat over an oil based stain is kind of asking for trouble or visa versa. I do not like the looks of a clear water based top coat, Amber softens the look.

The first coat of Seal coat dry in about ten minutes. If you want more amber. apply two coats of seal coat. Even more amber apply the amber shellac shown and then have put on another blearier coat of seal coat. And then top coat. If using old pine, top with Minwax antique oil and you will love the color you get.

[Derek Arita]

Great idea with the steel wool. I'll try that first, then if I don't like that, I'll apply some Seal Coat and Poly over that.

[Doug Garson]

For what it's worth. https://www.youtube.com/watch?v=7kCnmW6mKCM&t=2s

[Jim Becker]

What you used is "waxy" shellac...so a best practice would be to put a barrier coat of Zinsser Seal Coat shellac over that to help insure you have good adhesion of your "poly" over top of the shellac. Anything with polyurethane resin in it doesn't exactly like to stick to itself even so the better you prep prior to applying it, the better off you will be. While some folks have been successful with directly coating over top of waxy shellac with "poly", the odds are less favorable in that situation.

[Mike Wilkins]

According to finishing guru Bob Flexner, you can use the actual top coat as a sealer coat. I have done so by thinning the poly approx. 50% and applying, usually by brush, 2-3 coats. Sand to knock off the dust nibs and then I apply the poly again, usually thinned to 75% poly with 25% mineral spirits. Faster build than a wipe on finish and easier to apply.

[Curt Harms]

What you used is "waxy" shellac...so a best practice would be to put a barrier coat of Zinsser Seal Coat shellac over that to help insure you have good adhesion of your "poly" over top of the shellac. Anything with polyurethane resin in it doesn't exactly like to stick to itself even so the better you prep prior to applying it, the better off you will be. While some folks have been successful with directly coating over top of waxy shellac with "poly", the odds are less favorable in that situation.

I wonder if they were successful because they didn't shake or stir the Bullseye. If regular shellac is left undisturbed for an extended time, the wax will settle out on the bottom. The top portion should be mostly dewaxed. I learned this from pouring the Bullseye into a glass jar. For whatever reason shellac cans would leak, I had a modest mess to clean up so now pour it into glass.

[Jim Becker]

I wonder if they were successful because they didn't shake or stir the Bullseye. If regular shellac is left undisturbed for an extended time, the wax will settle out on the bottom. The top portion should be mostly dewaxed. I learned this from pouring the Bullseye into a glass jar. For whatever reason shellac cans would leak, I had a modest mess to clean up so now pour it into glass.
yes, that's absolutely a possibility.

[Derek Arita]

So, I hit the glossy shellac finish with #0000 steel wool. It worked great and gave me the finish I was looking for. As I've said, I'm not a good finisher and do as little as I can. I was hoping to get an aged look. I'm hoping I got closer than not. Thanks for the help! https://i.imgur.com/BwBQWaF.jpg

[Jim Becker]

That looks really nice!!