You mean the stain? As many times as I sand it, I guess. And, remember, the stain isn't really a stain; just some rust laden vinegar.
It makes a really good visual gauge to let me know whether I've sanded a part or not.
Plus, I do it when I glue to make sure it's black under the glue line.
Next up: A brace for the inside of the top. I'll be using a strip of 3"x1/8" cherry that I picked up at Woodcraft.
This is much wider and thicker than what you'd normally see inside an acoustic, in fitting with my armored hollowbody theme.
I have freshly sanded, stained and washed the inside surface with mineral spirits so I can glue the brace on.