Official Luthiers Forum!

I have to admit that I did not follow the project real closely but suspect the blotch issue on the top comes from variation in the grain at differing openness i.e. Not being sized this will cause places where the shellac will absorb a bit into the top at spit coating and just lie on the top in others. This will effect the color leading to the splotch affect.

I have often not sized spruce when French polishing but I always raised the grain with distilled water first then sanded back with 220 before spit coating. But the more I work with finer spruces the more I find myself sizing with egg whites a day a head of spit coating.