Gel Coating Vinyl Ester

[Mooncusser]

Does anyone know for certain whether gel coat will form a chemical bond to Vinyl Ester?

[Scott]

Vinylester is just a more resilient, and a bit more water resistant form of polyester resin. A lot of builders …I think even SeaCraft …. Use it today
Isothalic(sp?) based gel coat is what I have used in the past over vinylester (Isothalic is just a higher grade of poly resin)
They even make a vinylester based gel coat for high wear areas like a hull bottom. Vinyl is a step above Iso ...and cost more too.. Remember the gelcoats are really just pigmented resins.

[Trayder]

It depends if cured or not-

Vinylester resins utilize a polyester resin type of cross-linking molecules and if applied "wet to wet" on poly gelcoat it will chemically bond. (like in a mold)

If you are doing a repair with vinylester resin, you should use laminating resin. Laminating resin stays tackyas it will not fully cure when exposed to air, this will allow you to get a chemical bond between the final layer of gel coat with wax or gel coat covered by PVA.

If the vinylester resin has cured, rough it up and shoot your gel-coat, the mechanical bond will be more than suitable.

[Trayder]

oops

looks like Scott posted while I was typing.

Scotts nails the point, gel-coat is a tinted resin.

[Fletch]

It has been working just fine for me. No problems at all...