Weird Artsy Project Question

You could try silicone spray. This would obviously waterproof it, too. That might not be enough, though, and you'd need to be careful to keep it a good distance to not damage it with the pressure from the nozzle, of course.

You might also try some sort of transparent laminate sheet. Maybe something like what's shown here. It would hold everything in place pretty well, I'd think. These are a couple of the first things to come to mind.

Maybe a spray adhesive?

Urgh, keeping anything made with charcoal intact is a pain in the ass. You'd need something to seal it in one piece, otherwise it'll constantly deteriorate. The problem with that is that if something happens to the piece during the process, there's no way to fix it. :S

Alright thanks guys! I'll see if I can find something!