Shellac dyed/tinted

[Fernando Esteves]

Hi!
We have some guitar painters herein Brazil, very little numbers and all of them I know works only with electric, they don't know about the thickness importance on acoustics.
The acoustic luthiers I know just paint the guitar themselves and very rarely get commission from other luthiers, I've talked with a good bit of the top luthiers about

So, as I don't know anything about painting and don't have demand/space to make a paint booth, I'm thinking in finish the archtop and acoustic I'm planning to do next year with shellac french polishing.
Problem is that the soundboard of the archtop has some ugly stain on it, so I'll need to paint it black...
Do you think it's easier to dye the top black and then varnish with shellac or mix the dye with shellac and then apply?

I'm thinking in get that nitro ebony finish of Gibsons look, not something translucide

Thanks

[Alan Carruth]

Alcohol soluble aniline dyes can be used with shellac, and you can get a decent opaque black that way. Make sure you get the right sort of dye; they're available in oil, water, or alcohol soluble versions. A friend of mine got some 'universal' orange once that turned out to be a mix of different colors that dissolved in different solvents. The stuff that didn't dissolve stayed suspended, and acted as a pigment. He mixed the dye with some lacquer, and when he went to wet sand it level the water soluble red particles started to run. It looked like somebody had pricked it all over with a pin, and it was bleeding. Sand back and start over...

[Fernando Esteves]

Thanks Alan!

[Bryan Bear]

Alan, if you are looking for opaque or very dark using alcohol soluble aniline dyes and the French polish technique, do you use lots of dye to get the shellac really dark, or should you error on more sessions of FP to build the color? I've never tinted shellac for FP but have noticed when I use darker shellac grades I can sometimes see that I am building more in some areas based on the color.

[Alan Carruth]

So much depends on the dye. I've used opaque pigments on occasion when that was what was wanted, but some of the dyes, most notably the black, tend to be pretty opaque in themselves. It's not something I do often, so I don't have a lot of experience to say what's 'best'.