CalicoKid
Lieutenant Commander
- Joined
- May 27, 2002
- Messages
- 1,599
Re: Lil' Dinghy
I went through all that scraping bad resin off building my canoe. It's no fun but the results are much better. I had a bad can of resin that would not cure properly. Between coats of resin, if you let it cure, be sure to wash the cured resin down with warm water and sand it with 80 grit. If you apply resin over cured resin, any kind, the new will peel away soon. If you do your layup all at once while the resin is wet or even kicked off but not cured you get the best bond, a single thick layer of plastic. If you do a layer and let it cure then do another layer you need to do the wash and sand prep to get a good mechanical bond between layers. Single layup is best but not always practical so be good about the surface prep.<br /><br />The link to West System has some info on poly (gelcoat) over epoxy in the boat projects section. Poly just doesn't make nearly as strong of a mechanical bond as epoxy does. It does make a fine chemical bond though which is why composite boats are laid up all at once in the mold. I feel epoxy is far superior to poly for home boatbuilding for this reason alone. We are not making these boats in a day. The lack of odor and the great accompanying products that make up the 'system' are bonuses. The only drawback is cost.
I went through all that scraping bad resin off building my canoe. It's no fun but the results are much better. I had a bad can of resin that would not cure properly. Between coats of resin, if you let it cure, be sure to wash the cured resin down with warm water and sand it with 80 grit. If you apply resin over cured resin, any kind, the new will peel away soon. If you do your layup all at once while the resin is wet or even kicked off but not cured you get the best bond, a single thick layer of plastic. If you do a layer and let it cure then do another layer you need to do the wash and sand prep to get a good mechanical bond between layers. Single layup is best but not always practical so be good about the surface prep.<br /><br />The link to West System has some info on poly (gelcoat) over epoxy in the boat projects section. Poly just doesn't make nearly as strong of a mechanical bond as epoxy does. It does make a fine chemical bond though which is why composite boats are laid up all at once in the mold. I feel epoxy is far superior to poly for home boatbuilding for this reason alone. We are not making these boats in a day. The lack of odor and the great accompanying products that make up the 'system' are bonuses. The only drawback is cost.