I just finished putting two layers of fiberglass on my Guillemot hull, and I thought I'd post a few observations for first-time builders who are getting close to this stage while the impressions are still fresh in my head. So:

1. Think about heat early - I put off worrying about my garage temperature all through my build, figuring that I would just put a heater in my finished-but-unheated garage and I'd be fine. After running two 1500 watt heaters all day I couldn't get the temp above 60, and my sealer coat took 48 hours to stop being tacky.

I ended up buying a roll of 10' 2-mil plastic and tenting off the boat. Even that didn't work until I sealed off every air leak I could find. After spending most of a work week's evenings trying to get it right I was able to get a 70 degree environment. Point is, even if it's fairly mild out (40's), getting a heated space to fiberglass might take some time.

2. Sealer coat - I recommend doing this if for no other purpose than getting used to how your epoxy is going to work. You can get practice with the various methods of spreading epoxy, and if you totally screw up you can sand out the runs and high spots.

3. Fiberglass layers - I used two complete layers of 3.2 oz (thayercraft.com) fiberglass, rather than a full layer and a "football" second piece to cover the bottom. I did this to avoid feathering in a smaller piece over a larger piece and I'm not too worried about the extra weight. In retrospect, feathering in a smaller top layer probably wouldn't have been that big a deal, and I spent significant time trying to get both vertical layers to wet out along the sides - particularly at the shear line.

4. Technique - don't worry about it. If you can apply a bumpersticker then you can probably get the technique down.

5. Mess - Initially I ended up with a large amount of drips, mainly from trying cover too much of the sides at once. I covered the important stuff under my boat, but I'll need to scrape off a bunch of hard plastic once I'm completely done. I'm OK with it now, but at the time I was angry and a bit frantic over the mess - WHEN I GOT RUSHED I MADE MISTAKES. So, if it'll take some stress off, install some sort of ground cover.

6. Air bubbles - I tried and tried and still have a number of air bubbles on the hull. These look like air bubbles under a bumper sticker - I used a fiberglass roller thing with some limited success but I may have to live with them. These are different than the fine "frothy" bubbles you get from using a roller, and I believe were made worse by wetting down two fiberglass layers at once. All this said, they're not *that* bad.

7. The ends - the ends gave me the most trouble, in two ways. As they're almost entirely verticle, it was difficult to wet down both layers. Also, I waited to cut the glass along the centerline tip so that I could fold over the layers flat and they got pretty messy. By "messy" I mean that the wetted-down tips were difficult to cut and fold, the glass started to fray, I was trying to balance an epoxy cup, spreader, sissors, and sticky gloved fingers, and because I waited until last I was hurried as my epoxy was starting to thicken. My advice would be to cut and roller the ends early in the process, then squeegie later to make it neat.

8. Gear - a proper organic respirator is a must-have. Mine was about $20 from the auto part store, good for 30 days stored or 40 hours working. I used a dust mask during the sealer coat, and ended up with a headache. The respirator is comfortable, doesn't restrict breathing - get one. I bought a painter suit and regret not wearing it, since now my garage sweatshirt has wet epoxy drips on the sleeves - the tyvek suit is probably worth it for your first big sloppy job.

All in all, as a stone novice I think my first attempt went OK - a double layer hull is probably the toughest section of the boat to glass, and I don't think any of my mistakes will be that glaring. In retrospect most of my fears went unrealized (eg my hull looking nothing like the pretty work I see on the forums) - and having gotten this under my belt the rest will go better.