Your better off using plain water and wet or dry sandpaper. Keep your micromesh for lacquers or urethanes etc., There is really no goodreason or need to sand shellac, that's a waste of time/material/and money.The high polish of shellac can be had when using the initial pad/rubber/tampon applier that contains a small amount of 4/6F pumice and oil, that will keep the surface smooth when friction polishing as the pad dries out.