I'll be starting the finish on a new instrument soon, and am attracted to the low toxicity of shellac as a finish material, but am not too crazy about its durability as a final finish.
So, what I'm wondering is if there is anything wrong with the idea of building up the majority of the finish film with shellac and then shooting 3-4 coats of laquer over that as a final finish. Presumably if I've built up enough shellac and have gotten it sanded flat, the thin lacquer coat wouldn't need much sanding before polishing, and there wouldn't be too great of a risk of burn through.
Would there be any need for a vinyl or nitro sealer coat between the shellac and the final nitro coats? I guess I should mention that I don't intend to use any water based materials.