Spraying shellac

[Rob Blaustein]

I'd like to use the Zinsser spray shellac can for a project I'm working on (ie, the can Zinsser sells with the spray nozzle). I've brushed and also padded shellac before and have a feel for how much shellac to apply, based on feel/tackiness. But I tried spraying on some test pieces and have no feel for how much to spray on in one application since there is no tactile feedback. Do I keep spraying until everything looks wet, or just try to cover the surface lightly and apply several coats? Is it necessary to sand between coats at all or just after the final spraying? I should mention that I'm applying shellac as a sealer coat after dying with a water-based dye, and before applying an oil based glaze (BLO + gel varnish + oil-based artist's colors) and oil-based varnish as a topcoat.
--Rob

[glenn bradley]

I spray till it looks glossy but, I only use their spray can for odd shapes or small parts. It has never really given me a satisfactory finish over any sizable area. It is dewaxed but does not use DNA as a vehicle so it is tough to to do any additional work beyond the finish you get. After it cures it could be sanded with a very fine grit to get a smooth base before applying your top coat. Since you have a feel for padding, I would really be tempted to go ahead and do that. I assume that your project contains elements that make spraying preferred.

[Rob Blaustein]

Thanks Glenn. Nothing really in this project requires spraying (shaker doors and drawers, with some solid drawer fronts), I was just thinking it would speed things up since I'm in a rush to get this part of the finishing done.
-Rob

[Scott Holmes]

A light wet coat is best. Two coats should be enough to seal it.

Now I have a question for you?

You said " ...oil based glaze (BLO + gel varnish + oil-based artist's colors) "

What is the reason for the BLO?

If your reason it is to make the glaze easier to work; use reg varnish instead of the gel varnish.

If you have another reason. I would like to know, it seems to me that it would make the glaze less likely to stay where I want it.

Another option for the glaze would be gel stain by itself.

[Rob Blaustein]

Thanks Scott. I'm not entirely sure why the BLO is part of the glaze and I was going to ask Jeff Jewitt that same question--I'm following the approach that he wrote about in his FWW article "Finishing Walnut" back in 2005. My sense from reading his other books and Flexner's is that the BLO helps enhance the figure and will also help prevent the glaze from setting too quickly. Since I'm a rookie I'm just following a known recipe for now.
--Rob

[Neal Clayton]

an oil will darken the grain a bit, versus a shellac sealer. which is a benefit imo since shellac is a film building finish and will therefore obscure the grain a bit. i use an oil varnish as a sealer for that reason myself.

spraying is definitely faster than wiping. you can spray coats about 3 or 4 minutes apart and there's much less of a concern with proper sealing. i don't bother with multiple seal coats, just one, and its primary function besides grain darkening is to highlight any spots that could use extra sanding that i missed, as much as the actual sealing. sprayed shellac dries before the wood can 'drink' it, so poorly sealed wood isn't as much of a concern. end grain especially is much easier to spray, since you're not pushing the shellac in, it dries on contact so the ends don't soak up too much, as they do with wiping or brushing.

you do have to be careful not to overdo the spraying and spray too much, or it will alligator. this is of course depending on your spray gun, you'll just have to figure out the limits of how much can be sprayed by trial and error. the results will not be as smooth as wiping, due to how fast shellac being sprayed dries it'll be kinda rough, actually. so it will have to be buffed before your top coat.

[Rob Blaustein]

I asked Jeff Jewitt this question. His response was that adding BLO to the gel varnish "gives it more open time and makes it easier to move around."

A light wet coat is best. Two coats should be enough to seal it.

Now I have a question for you?

You said " ...oil based glaze (BLO + gel varnish + oil-based artist's colors) "

What is the reason for the BLO?

If your reason it is to make the glaze easier to work; use reg varnish instead of the gel varnish.

If you have another reason. I would like to know, it seems to me that it would make the glaze less likely to stay where I want it.

Another option for the glaze would be gel stain by itself.

[Scott Holmes]

Hi Rob thanks for the reply...

So JJ agreed with what I said "...your reason it is to make the glaze easier to work"

Did you ask him about the rest of my statement "...(or)...use reg varnish instead of the gel varnish."?

Also, if you use BLO you are creating and oil/varnish blend glaze which will dry very soft and should not be used with a graining tool. It will wrinkle up under the top coat.

[Rob Blaustein]

Scott--I didn't ask about reg vs gel varnish. What's a graining tool?

[glenn bradley]

I asked Jeff Jewitt this question. His response was that adding BLO to the gel varnish "gives it more open time and makes it easier to move around."

Not that I need to add anything to Jeff J's statement but, BLO is used to help paint flow better and extend the "workable" time. Sounds like Jeff is after this quality of BLO for the recipe and any coloring influence is secondary.

[Rob Blaustein]

An observation worth mentioning re dye then shellac: I noticed that after applying Transtint dye followed by shellac, the walnut actually looked a bit drab. The dye does darken the grain but after the dye shellac combo, the figure of the wood was actually less prominent. When I spoke to Jeff about another issue, he independently mentioned this observation as well. But I did notice, and Jeff also pointed this out to me, that after applying the glaze and varnish (or even just a varnish) the wood looks much much better.

[Scott Holmes]

A tool used to add faux grain to a glaze coat. Glaze coats are color added between clear coats. Gel stains or glaze works best. Adding BLO to make it more workable will make it very soft.