Do you epoxy clear coat all surfaces of a guitar at the same time?

[Bob V]

If you haven't got spray equipment, you might consider rattle cans from reranch.com. Also some of the home centers carry nitrocellulose lacquer in spray cans. It's very forgiving since it melts into the last coat and it levels out very nicely and dries before any dust nibs can settle on it. If you screw up, all you need is a rag and some lacquer thinner to strip it off. You'd probably want some "sanding sealer" to start with because it's easier to sand back to a level surface after the first few coats, then switch to a regular nitro topcoat. On rosewood or mahogany you'd want some type of grain filler - you can do without it of course but there will be pinholes showing.

Otherwise you can use any of the wiping varnishes or oil finishes that can just be applied with a rag. the most popular of those is Tru-Oil which is polymerized tung oil and it's available in sporting goods stores in small bottles meant for finishing gun stocks. This won't build up into a true gloss finish (unless you do a thousand coats of it, it can be done though).

On the other hand, I prefer water based coatings because it's a joy to clean out the spray gun with warm soapy water in the slopsink. I get mine from Targetcoatings.com

Oh, and as for the OP's question, you might want to seal the top before staining or filling the sides in order to keep any pigment or dye from getting on the top. Then once you catch up with the sides and back and you're ready for topcoats, you can spray the whole thing with whatever clear final coat you're using.