Epoxy in mould

[gary1]

Afternoon,
I was just wondering is it possible to use epoxy in a boat hull mould, I have noticed that just about all the questions in regards to laying up fabric up in a mould involves either Polyester or Vinylester types of resin. Is there any other reason besides cost that Epoxy isn't commonly used in a mould.
Thank's
Gary

[Herman]

There are 2 main factors why epoxy is used less in a mould:

-cost. For general marine industry, epoxy is too expensive.
-surface. There are no epoxy gelcoats available which survive sufficiently in a marine environment.

About cost:
Of course price of the resin is a factor, however, with a carefull engineered laminate, less resin can be used. A huge cut on fumes (styrene) can be generated, and the boat is upgraded from "grp hull" to "high tech epoxy construction".

About surface:
Basicly there are 2 feasable options:
-1. Apply a good quality polyester gelcoat (ISO-NPG) and apply a vinylester laminate. Let cure, sand and continue with epoxy.
-2. Do not use a gelcoat at all (or apply some sluggish epoxy as a gelcoat, to prevent fibers on the surface) and paint the hull afterwards. (above waterline with PU, below with a suitable coating for the area the boat is used.

[gary1]

Thank's Herman,
Appreciate the reply just settled a query that I have been wondering about for a while.
Thank's
Gary