Official Luthiers Forum!

Anyone out there regularly spray shellac as their final finish? I've been having a bear of a time of it. From what I've gathered from the archives, light dry coats work best. So thats tip one, I've been going too heavy with a 2# cut. Either orange-peeling or running and then sanding through. Whoopee! I'm glad my wife and kids are out of town or else they'd be hearing it. Dog is hiding....

I love the idea of bug shells on a guitar versus plastic or toxics, and I've never gotten the hang of FP, so if anyone has spraying shellac wired, I'd love to hear about it. I'm using one of those Rockler $90 hvlp rigs...

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Gabriel Regalbuto
Carlsbad, California
Freedom 35!

A lot of folks spray shellac as a sealer coat - when I spray I probably end up with a bit lighter than a 2# cut though. People I know who spray it for build will typically french polish out the top coat - Tom Humphrey did that with his guitars. I'm not sure if I know anyone who sands and buffs a sprayed shellac finish - seems like you would have to spray it thicker than I normally think of shellac thickness to minimize risk of sanding or buffing through.

Maybe some people do spray/sand/buff shellac, but I've not done it myself. As to the orange peel from spraying, I often use scotch-brite to level it up, at which point it's not too difficult to do a bit of solvent-heavy french polishing then hand rub it to a gloss.

This is certainly not an area of expertise for me though, and I'd be happy to hear of other ways.

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Eschew obfuscation, espouse elucidation.

I've done a few. I spray at about a 1-1/3 to 1-1/2 lb. cut. I would not say I spray "dry." I look for a glossy pool behind the path of the spray, just as with lacquer. Of course, you move the gun too slow, you get a run. It's been a few years, but iirc, I hold the gun a little closer to the work than I do with nitro. Same nozzle. It really has been pretty straightforward for me; I never figured out why it's supposed to be problematic.

I have found it hard to get a good gloss with machine buffing; maybe the heat.

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Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

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What Howard said. I've done a few with very good results. Make sure the shellac is very fresh and good quality flakes. Spray two or three coats (in the same day if you wish) and wait several days to harden. You can then wetsand with 800 or 1000 (lightly) and then do the same all over again. When you've gotten things fairly level and built up enough to get out 80-90% of the pores, etc., wait about 2 weeks or more and then spirit off using french polish method. I use a pad with lint free shop cloths from Ace Hardware, cheesecloth packed inside, and use just denatured alcohol with plenty of extra virgin olive oil. Keep the pad lubricated enough to keep it smooth and you'll be surprised. Watch for the 'comet tail'. Machine buffing doesn't do very well for me either.

Best of luck.

SR

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"We might not be big but we sure are slow"

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I've did one that way, and I didn't find it very difficult ( it would have been even easier if the it wasn't a sunburst finish where sand throughs can be a real nightmare...). I used the same set up as with nitro lacquer; gravity feed touch up gun, 1 mm tip, and I used about a 2lb cut of blonde shellac flakes in denatured alcohol iirc. Like others I didn't have much luck with machine buffing, so I ended up doing everything by hand. It polished up quite shiny, and the 'glow' was deeper than I have seen with nitro.

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Rian Gitar og Mandolin

Micromesh and Meguiars just don't do it for me. Call me crazy but I get some self-gratification, if you will, from the french polishing method and probably do it just as fast as your method maybe a little slower. Just a few short sessions on a properly prepared finish get me real close and I love the glow it brings about. Not the same as buffing or polishing compounds. There's just something satisfying about it that goes along with my love for lutherie. I guess you could compare it to those who prefer to build without using any power tools...sounds like a lot of work but I can understand the satisfaction one would get.

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"We might not be big but we sure are slow"

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Well I sprayed a few coats with about a 1.25# cut. I also moved the rig a bit closer and between those two changes I've gotten much flatter results. I'll give the scotch pads a try when I go to level, I had been using 600 wet with a block.

I was surprised to see extra oil recommended for final (French) polishing. The video I watched recommended reducing the cut and the oil for final polishing. I've always ended up with swirls and just given up and gone to abrasives. I suppose I'm going to have to try this as well...

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Gabriel Regalbuto
Carlsbad, California
Freedom 35!

I wet sand using water with a drop of dish detergent. Works fine.

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Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.