I bought a swamp ash Strat style guitar body and started the staining and sealing process. I used a "MiniWax" Cherry color stain. I've been spraying a MiniWax oil base Gloss PolyUrethane finish. Will this deaden the sound of the Swamp Ash Wood or is this exceptable. Also, on the last coat of gloss, what grit do I use to buff it to a smooth finish?