Polyester vs. vinyl ester vs. epoxy resin

[ontherocks]

What do you guys recommend if you had a choice from the start in building a boat (poly, vinyl or epoxy). Polyester seems to be the least expensive, but are there any major drawbacks in using the polyester as opposed to vinyl or epoxy, when the boat is first being built. The boat would be a small 15 ft skiff. Thanks.

 

[Sailorgp]

How do you plan to construct the boat? Laminated fiberglass? Stitch & glue plywood? plank on frame?

 

[Sailorgp]

there's also cold molded and strip planking. Your choice of construction methods would dictate which resin is best suited for the job

 

[ontherocks]

Fiberglass. I'm probably going to have someone build it, but since its semi-custom, i figured id ask to see what you guys thought. Thanks.

 

[RKrough]

All 3 resins create a structure by bonding to a fiber or surface and then hardening. Epoxy bonds better than polyester, Vinyl-ester is in the middle. Perhaps an over simplification but IMO it is the most important difference. Polyester works just fine IMO with the cloth and chop fillers that is designed for it. but if this is a cold molded or strip planked hull and your builder is including polyester as an option, find another builder.

FWIW I have two 30 year-old boats with polyester fiberglass hulls and they still float just fine.

 

[jojobee]

I would skin coat the hull with vinylester. Especially if you are bringing the boat to warm water. Most builders offer this. If the boat is cored below the water line, I would go with 100% vinylester below the waterline.

 

[John Riddle]

OntheRocks:

Generally, except for high-end boats using higher-tech materials (carbon fiber for example) it's unusual to lay up a fiberglass hull using epoxy resin. One factor is probably its higher cost, although that may be negligible on a 15' hull. Polyester and vinylester resins are the norm in a typical fiberglass layup and as the other guys above implied, they can be used together to advantage in the same structure.

If you are considering a design that is not actually in production anywhere, I'd be happy to quote it. Just email me from my profile and we'll get together.