Fiberglassing Old Dory

Hello.
I’ve inherited an old Gloucester Dory. It’s a bit of a mess with some rotted wood but I think it’s all repairable. This boat is built from thin plywood. I’ve belt sanded most of the old paint off. The bottom is fiberglassed which wraps onto the side up to the waterline. The bow is fiberglassed with much rot. Some of the original fiberglass is missing exposing the ply. I plan on coating the exposed areas with GitRot and filling bad areas with GitRot /sawdust mix.
A few questions (please keep in mind I’ve not done any fiberglassing before).
1). From reading I’m thinking 1708 glass blanket should work okay. Does this sound okay? But I’m looking for suggestions on blanket weight and weave type.
2). I’m assuming I can glass over the old (original) fiberglass ??
3). I’d use epoxy (rather than polyester resin).

This boat would be used in a fresh water pond only. I’m just looking to make it “sea worthy” not a show piece.
Thanks for any help and suggestions.

 

Git Rot is mostly garbage. For small cosmetic repairs it is acceptable, but not for structural repairs. Simply cut off the rotted area in the bow and replace it. Wood is cheaper too.

 

+1 re Gonzo's comment above.
Re the existing fibreglass, if it is sticking well to the plywood, and the plywood is not rotten underneath, then you might as well leave it in place.
It sounds like you want to add another layer of glass on top of this existing fibreglass?
How thick are the plywood panels, approximately?
Do you have any photos that you can post of the boat please?

This book might be useful for you for reference?
Build the Gloucester Light Dory – H.H. Payson & Company https://www.instantboats.com/product/build-the-gloucester-light-dory/

 

1708 is a rather heavy layer of glass for a plywood boat that already has glass on it. With epoxy you may only need a single layer of 6 or 10 Oz cloth.

And like mentioned, git rot is worthless for this project.

 

Skip the gitrot bandaid. Won’t help.

Remove all delaminated glass.
Remove all rotten/delam ply.
Remove and replace with precision all framing with any rot OR remove all rot and fill with epoxy and filler.

Replace plywood, seams usually not on framing require butt blocking with new plywood.

precoat all raw wood with epoxy before glassing or any bonding

lay two layers of 6 oz glass over bottom subject to abrasion or 1 10oz min

apply fairing/finishes