Masonite (hardboard) as base for Fiberglass

Hello,

I am designing benches for a sailboat and am thinking about using masonite as a base form for fiberglass. in other words the benches would be made from Masonite then covered with fiber glass.

Is masonite a suitable base structure for Fiberglass in a marine environment?

Thanks!

 

Masonite will not hold up in the marine environment, but you can use it as a form, knowing full well it'll break down with moisture exposure. If the laminate is heavy enough, the masonite is simply a mold over which the wet fabric is applied, when it's dry, the masonite is just along for the ride.

 

Quite some time ago we used to use masonite as a contact tooling surface for fiberglass molding, the dense smooth side was coated with shellac, waxed then pva Then molded off, now melamine faced sheet or polyesterboard-coated ply is easier.
Seen quite a bit in lockers & also perforated masonite used as a lining panel form 50-60-s boats typically cruisers..
Given the choice I wouldn't use as a form to leave in.

Jeff