My thoughts on the subject from another thread:
I've done a lot of fiberglass work, surfed for twenty years so repairs were necessary. Also worked in a shop that made custom bodies and fairings for motorcycles. It's not difficult to do but can be dangerous if you don't know what you're doing. The fumes are toxic, plus the sanding dust makes you itch like mad and never comes out of nylon clothing so you end up tossing any clothes it gets into. If you mix a hot batch of resin it can create enough heat to burst into flame so it's best to watch the parts set up.
When I was learning how to laminate I asked the guy teaching me if there was some sort of laminators union. He said "Nah, nobody in this business lives long enough to start one."