Repairing hole in polyester fiberglass boat

I have a small sailboat that was dis-masted in an accident. It is the type of design that has a compression post inside the cabin, supporting the mast step on top of the roof. The accident left a hole in the cabin roof, about 3” x 4”. This is what is regarded as a structural area but I believe most of the strength necessary is provided by the compression post. The horizontal forces are minimal since the mast is supported by shrouds and stays.

The boat is polyester fiberglass. I have lots of experience with epoxy fiberglass, having built several fiberglass-over-wood boats and have made undetectable repairs when needed. However, I have zero experience with polyester fiberglass or gel-coat. So I have a few questions.

I read in Allan Vaitses’s book, “The Fiberglass Boat Repair Manual,” that epoxy fiberglass can be used for repairing polyester boats, but I do not know if I can apply gel-coat over epoxy fiberglass. Is this possible? If so, I think that will be best.

If not, I know epoxy is very strong compared to polyester, so my other idea is to use epoxy fiberglass on the underside of the hole (inside the cabin) with perhaps one or two layers of fb cloth. I would then use polyester fiberglass on the top of the cabin roof and finish with gel-coat. Do you have any advice regarding that possibility?

A third option would be to make the repair with epoxy fiberglass and cover it with a good quality paint like Interlux Topsides. The boat is white so it should be easy to match.

Do you have any advice or opinions to offer in regard to this?

Thank you for taking the time to read and answer this.

Dana Cole

727 W Lakeshore Dr

Stillwater OK 74075




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