I'm currently building one of these for my son, and I'm interested to pick you brains for finishing ideas. I've been able to sand it pretty smooth so far, but the plywood isn't that great. I think I'm going to have to grain fill it to get a decent finish. I need some sort of finish that will be able to cop a beating, literally, and help to protect against splitters (not a great thought for an instrument you sit on , and beat with your hands. Contrary to what it has said in my signature, I think I've decided that Wudtone is not the way to go due both to the cost and the lesser quality of the wood involved.
Any ideas?