My chosen finish is a shellac finish using a french polishing method. I've sanded everything and started the first part of the process - pore filling. Pore filling is the process of filling spaces between the grain of the wood. It's very important on the wider grained wood (usually the sides, back, and neck). I've read about 2 types of pore filling. One is using shellac mixed with pumice powder. I briefly thought about this and may try it on the next guitar (yes, I've decided there will be a next guitar) but instead chose the other method I read about. That method is using Epoxy to fill the grain. I'm not trying to get the wood covered with epoxy but rather just the spaces between the grain. I'm going to do a few coats though coats are probably a misnomer. After one coat, you sand the surface which should remove all but the epoxy in the pores. The reason for repeating seems to be to ensure an even/level surface that has all pores filled.
The big reason for this is that the woods used in guitar building are often open pored woods and the finish will often shrink into the pores. The result of this shrinkage is that the finish cracks (somewhat like orange peel finishes). In a guitar this would be a bad result.
My first coat of epoxy went on well so I'm hopeful that the sanding and additional coats will go on smoothly as well.