Shellac as a base coat

[javajake]

I picked up some amber shellac yesterday that I was planning to use as a base coat before applying some poly. The label says this is not recommended, and that their base coat shellac should be used instead. Is there any good reason I can't use the shellac I bought? It's Bullseye, by the way.

[Kari Hultman]

Is the Amber shellac waxed or dewaxed? You can put (dewaxed) shellac under or on top of any finish, so it would not be a problem for you to use it the way you had first planned. Their base coat is probably just thinned shellac (thinned with denatured alcohol).

[javajake]

Is the Amber shellac waxed or dewaxed? You can put (dewaxed) shellac under or on top of any finish, so it would not be a problem for you to use it the way you had first planned. Their base coat is probably just thinned shellac (thinned with denatured alcohol).

I will have to look at the label again, I don't remember it saying if it was waxed or dewaxed... I was thinking maybe their base coat was just thinned...

Thanks Kari (The Village Carpenter?)

[AceHoleInOne]

Java Jake, is the poly water-based or oil based?

-Ace-

[javajake]

Java Jake, is the poly water-based or oil based?

-Ace-

Oil based

[Kari Hultman]

You might try it on a test piece of wood first, just to be sure. Let us know how it turns out.

~Kari (village carpenter)

[thewoodwhisperer]

If its amber and its made by Bullseye, you are looking at a 3lb cut of waxed shellac. If I'm not mistaken, the only product they make that is specifically de-waxed is their SealCoat and that is a clear formula. You can manually dewax your shellac assuming the wax has separated. Usually if you leave it long enough, the wax will settle to the bottom and you can pour off the clear portion at the top, which is essentially de-waxed.

Now this is one of those experiments I really want to try. Or perhaps someone with specific experience can tell me the story. But I feel like the concern about putting poly over waxed shellac is a bit of a myth. But at the same time, I am not willing to try this out on a real project just to see what happens. Well shoot. There's my mission for today. Im going to home depot to pick up some shellac just to try this out. I'll see if poly has any problems adhering to a waxed shellac undercoat. I'll report back.

Just to be safe though, I would either buy some dewaxed shellac or simply pour off the clear stuff. Better safe than sorry.

[AceHoleInOne]

Java Jake, interesting, who is the poly manufacture?

-Ace-

[javajake]

If its amber and its made by Bullseye, you are looking at a 3lb cut of waxed shellac. If I'm not mistaken, the only product they make that is specifically de-waxed is their SealCoat and that is a clear formula. You can manually dewax your shellac assuming the wax has separated. Usually if you leave it long enough, the wax will settle to the bottom and you can pour off the clear portion at the top, which is essentially de-waxed.

Now this is one of those experiments I really want to try. Or perhaps someone with specific experience can tell me the story. But I feel like the concern about putting poly over waxed shellac is a bit of a myth. But at the same time, I am not willing to try this out on a real project just to see what happens. Well shoot. There's my mission for today. Im going to home depot to pick up some shellac just to try this out. I'll see if poly has any problems adhering to a waxed shellac undercoat. I'll report back.

Just to be safe though, I would either buy some dewaxed shellac or simply pour off the clear stuff. Better safe than sorry.

Sweet. Thanks, Marc.

[javajake]

Java Jake, interesting, who is the poly manufacture?

-Ace-

Well, I have a gallon of Cabot Spar Varnish. I am planning on using that at this point.

[AceHoleInOne]

The Cabot is a "spar" varnish formulated for outdoor/high moisture. The spar is a soft"er" more flexible finish that will expand and contract with the wood and not crack. So the directions indicate not to apply over shellac or lacquer. I'm no expert on spar varnish, however my thoughts on this is that the spar is self-sealing and should link itself directly onto the wood for a good bite so that it can expand and contract with the wood.

-Ace-

[javajake]

The Cabot is a "spar" varnish formulated for outdoor/high moisture. The spar is a soft"er" more flexible finish that will expand and contract with the wood and not crack. So the directions indicate not to apply over shellac or lacquer. I'm no expert on spar varnish, however my thoughts on this is that the spar is self-sealing and should link itself directly onto the wood for a good bite so that it can expand and contract with the wood.

-Ace-

Well, it's going on a bathroom vanity near the tub/ shower. I was going to use the shellac as a base because I have heard that cherry can be blotchy sometimes with straight poly. I wonder why it says not to put it over shellac?

[javajake]

Well, I've got one coat of the amber shellac (I didn't mix it up, though - just took it off the top) and two coats of spar varnish on a scrap of cherry in my shop... Guess we'll see what happens...

[bbast]

The base coat shellac is thinned, the base coat works as a better sealer and when you put additional coats of shellac it doesn't "stick" as much. Do not know about the poly. I have a sample board board with base coat, amber and clear on it, will put some poly over it and see what happens. Biggest issue will be how long will it take to find out if there is a failure.