How Long Will a Fiberglass Boat Last ?

[irwinsailor]

Our boat was in the water for 1 full year and the bottom job looks like new. I hope that continues.

[Sonosailor]

Fountaine Pajot builds their boats out of isophthalic polyester resin, which, according to them make them more resistant to water absorption and blistering. They prefer that repairs are done with the same material. They suggest that, because of this resin, special blister protection is not, or possibly less, necessary.

I know nothing about isophthalic resins. Anybody care to comment? (not about how little I know, please)

[irwinsailor]

Some boats are made of epoxy resin because it is water proof. I think Tartin is one builder that does. OK Jeff take it from here.

[GordMay]

Iso & Ortho - Polyester Resins were once the standard products for hand layups.

Many manufacturers are shifting towards Vinyl-Ester and Epoxy Resins, due to their better laminate qualities:
~ Better Blister-Resistance
~ Better Hydrolytic Properties (Water Resistance)
~ Stronger Bonding Properties (Adhesive Strength)
~ Lower Styrene Emmissions (MACT Restrictions).
~ etc...

Or, so I'm told...


and from BoatUS “BoatTECH Guides” :

”Resin Boat Talk” - From http://www.boatus.com/boattech/ResinBoatTalk.htm

Polyester, epoxy, and vinylester resins are the basis of barrier coats and fillers. The viscosity of all three allows for an easy, flowing application. Several types of thickening and strengthening products are availabl, such as reinforced short-strand glass fibers, which turn the products from a thin, syrupy consistency to a thick putty.

Polyester Resin - How It Works:

Combines with the catalyst Methyl Ethyl Ketone Peroxide (MEKP) to create a hardened product.

Best Use:

Repairing any polyester product, including most fiberglass boats.

Application Advice:

The least expensive of the three resins, polyester can be used over a broader range of temperatures than vinylester. It's not necessarily good for bonding to vinylester or epoxy. It's most siutable for above waterline repairs because it tends to let water pass through more easily than epoxy or vinylester, so it's more prone to blistering.

Epoxy Resin - How It Works:

Cures basically in the same manner as two-part polyester resin, but uses different chemical bases that provide better adhesion, strength, hardness, durability and water resistance.

Best Use:

Wood, plastic, and fiberglass repairs above or below the waterline and as a barrier coat.

Application Advice:

Epoxy won't blister like polyester because it absorbs less water. If your original repair was made with an epoxy, then it's best to stay with an epoxy. Epoxy is more expensive and tends to take longer to cure than polyester and vinylester - generally 24 hours between coats. Meticulous surface preparation is required. You must sand the surface free of amine blushes (which come to the surfacesuring the curing process) before applying gelcoat, primer, and paint. Apply 4-6 hours after sanding. Not recommended for use when you have a minimum amount of time.


Gord

[irwinsailor]

I guess I should have said take it away Jeff and Gord!

[irwinsailor]

bump!

[capt lar]

Thanks Irwinsailor. I did a search before I posted, but did not find this thread. Good reading.

Larry

[irwinsailor]

I thought that the question was answered well in this thread and would cover many of the questions that would come up in the other thread.