1) Read directions very carefully. The directions said equal number of pumps of hardner and resin for the fiberglass epoxy. This is not the same as equal amounts! The pumps deliver different amounts, it is actually 5 parts resin for every part hardner.
2) The $10 extra for the mixing pumps would have been a good investment.
3) Don't underestimate the amount of time it takes to clean the bottom of a barge before you can paint it.
4) Circular sanders can take off the top of your finger (I didn't actually learn this, but I suspect it is true).
5) Fiberglass is cool!
6) Bottom paint is far more expensive than I ever imagined. ~$100/gallon
7) Fiberglass resin tastes terrible.
8) Wear a mask and glasses that cover your eyes even along the sides (I didn't have to learn this one either, smart enough) when sanding fiberglass.
9) I am not a morning person
10) Bottom paint is poisonous.