I watched a few boat building videos and felt brave enough to attempt the fiberglass. It was actually a lot easier than I'd feared and I got two coats of epoxy done in one day. I wanted to do a third (and maybe a fourth) coat but I had no more rollers.
Helpful tools:
-The measuring pumps for your system, don't bother fiberglassing without these as doing it by volume otherwise takes too much time and isn't as accurate.
-Cleaned food-grade containers (stamped recyclable 5/PP) for mixing cups, I used 32oz tubs and thought they were a great size.
-Disposable paint roller trays (also marked recycleable 5/PP) for the roller (both these and the cups can be reused, the epoxy won't stick to them so you can peel the dried epoxy off the next day without cleaning them)
-West 800 roller covers (cut down to 4", have extras beyond what you think you'll need because the epoxy will destroy the roller in ~30 minutes, you'll have to break the covers off the roller with a screw driver at the end of the session),
-Aluminum roller (
like this) for pushing down the fiberglass whenever it comes loose from the substrate
-A good pair of steel office scissors, not modern plastic junk, Xacto knife and utility knife for cutting the fiberglass.
-Tiny epoxy syringes, for when you find air bubbles under the fiberglass, drill with a ~3/32" bit and use the syringe to fill bubble.
-500 pack of tongue depressors, cheap mixing sticks.
-Nitrile gloves
-Plastic squeegee for moving excess epoxy around
-A gallon of acetone and a glass mason jar for clean-up and easy brush washing
A few tips I found:
At the end of the day, disassemble the aluminum roller and drop the head in the acetone otherwise it will be a pain to clean later. Run acetone through the syringes multiple times to ensure they're clean (they're cheap, buy like 5 of them just in case).
The fiberglass WILL move on you, it will also stretch if you try to move the wet sheet, leaving wavy edges. Since my tear is going to be painted, I marked the centerline of the tape with a Sharpie whenever it was going over a corner so I had an easy reference point. I also marked the ideal outline of the tape on the tear for another reference line. Leave the fiberglass 1+" long, it will wick some of the excess off and then dry, which you can trim with a knife later much more easily than trying to keep a just-long-enough piece in the right spot. Overlapping and sanding down is much easier than filling a low area. I taped the fiberglass in place using painters' tape. Fold over ~1/4" of the tape to form a pull tab, so it is easier to grab while wearing gloves, hold the fiberglass with one hand while pulling the tape off to prevent distorting it.
I chose to use the dry-layup technique, where I put the fiberglass down and then put the epoxy on top of it, forcing it through the fiberglass and ensuring the glass was completely filled as it was recommended by West for my 105/206 (slow hardener) combination. Some recommend wet-layup where you put down epoxy first and then put the fiberglass on, the problem with this is that the fiberglass will float on the epoxy and does not stick down as nicely. Wet-layup is also much more time limited (have to get the entire lay-up done before the epoxy dries) while the dry lay-up lets you move at your own pace (within limits). Use 5-8 pump batches to have a decent amount of epoxy and enough time to use it all, do one pump of epoxy, then one pump of hardener and go back to the epoxy so you don't lose count and mess up the ratio. Start early in the day so you can get 3+ coats while the epoxy is wet, since if the epoxy dries you need to let it cure completely and then sand before applying another coat. Sanding epoxy, even with an orbital sander, is a gigantic pain.