Re: Does spray paint sound better than polyurethane?
Couple things…. First, “nitro” is a lacquer (nitrocellulose lacquer). Second, a number of paints are available in spray cans (epoxy based enamels, enamels, acrylics, polyurethane, several kinds of lacquer, etc). Some are more suitable for certain applications. You can buy guitar quality lacquer in a spray can from reranch.
I see nothing wrong with using a high quality poly finish on a guitar. In fact, doesn’t Fender spray North American models with the same PPG automotive mixes that many finishers are using? I believe the finish is applied solely to beautify and protect the wood. While lacquer may allow the wood to breathe and dry out over time, I dare anyone to hear a sonic difference between a freshly painted lacquer body and a freshly painted polyurethane body.
FWIW, I’ve heard people refer to import finishes as sprayed polyethylene. I don’t know if this was a joke, or if imports really are spraying plastic onto their guitars. I do know that shell around my RG only came off with lots of sanding. It sanded like plastic, not like paint. Regardless, I think it's really a polyester paint used on imports.