Resins

I feel like this is a stupid question but I have never had to do fiber glass work on my boat. When you lay down the epoxy resin along with the fiber glass cloth, dose the resin turn into the hard shell on the out side of your boat? Or is that a finisher you put on after the resin has dried?

Thanks

Re: Resins

The "hard shell" on the exterior of most fiberglass boats is gelcoat. It is the protective/cosmetic coating applied over the laminated fiberglass.

Re: Resins

When mixed properly epoxy resin will start as a fluid about the consistency of thin syrup. As the reaction takes place it will begin to turn to a gel. In its final stages you may detect a small amount of heat coming from it as it hardens to a point where you can scratch it with a finger nail. In the final stage of cure it will be very hard and can be sanded.
Resin is generally finished in one of two ways. Most boats are built, not using epoxy, but polyester resin. Polyester is very different and is finished by a coating of gelcoat. More accurately, gelcoat is the first layer applied to a form when making a fiberglass part. When removed from the form the gelcoat is the outermost layer and is normally pigmented with color. The most common color is white.
Epoxy has gained allot of popularity as a repair resin. The most prevalent reason for this is that epoxy resin has bonding properties that are superior to polyester resin. One down side to using epoxy resin is that polyester does not bond well to epoxy. Gelcoat is a polyester product. So it is common practice when making repairs using epoxy that the finish surface gets painted rather than recoated with gelcoat.
If you intend to coat your repair with gelcoat it is best to use polyester resin. If the finish is going to be paint, epoxy can be used.

Re: Resins

That answered my question! Thanks!