how to varnish a guitar body
1 Apply pre-stain liberally to the guitar body. 2  Apply the stain. 3  Make sure the stain, gel stain or dye stain is applied evenly. 4  Rub into the grain, going with the grain for an awesome effect. 5  Use bleached 100% cotton cloth to stain if you are using an oil stain, and rub into the grain of the guitar body. Wipe the end of the cloth gently against tissue paper until it is almost dry. 2  Rub the cloth on the spotted area of the guitar body. 3  Re-apply the stain to the guitar body. 4  If using an oil stain the process merely needs to be repeated. 5  Or use normal stain, finishing by rubbing with tung oil.