Look at the second reply in
http://forums.hunter.sailboatowners.com/showthread.php?t=102896, I post a couple links. The second link I posted shows what you need to do. It references Devcon Plastic Welder and, although I've not seen it at Wal-mart (as indicated in the repair manual) I do see it at REAL hardware stores or, strangely enough, at the local Harbor Freight store. It's wonderful stuff.
I just completed repair of a couple minor and one long but non-structural crack and I can state that the repairs work. I would suggest a few things:
- Use wet sanding techniques, they worked better for me.
- Don't use anything other than isopropyl alcohol to clean the surface
- Don't skimp on the V-groove but be careful - the AGP is soft compared to fiberglass resin
- The repair manual starts with 220 sandpaper. Resist the temptation to go lower. I started at 220 and worked up. If you don't paint, you can get a great finish by going up to 1000 or 1500 grit.
- I started to paint as indicated in the repair manual but need to practice my spray can techniques a bit more for good results. I may or may not paint the repairs but if I do I'll use an airbrush instead of a spray can.
The manual also talks about using MarineTex for small surface cracks. I was tempted to use this as the white color would have matched the hull pretty well but I've also seen this delaminate in the past. The Devcon PlasticWeld is wonderful stuff, however, accept no substitutes! If the surface is prepared properly, you will get a very strong repair.
Thanks to whomever runs the Sailing Obsession site where the AGP repair guides are posted!