An All Fibergalss Small Boat?

[Rich M]

Okay,

I built this little boat:



For ease of description - 10 ft long, 36 inch FLAT bottom, 44 inch max width. The sides have a 45 degree angle and gives it some serious stability for its size.

My dad (in the picture) wants one and I know he can't handle the 85 pounds it weighs built with ply & polyester glass. If it is possible to do an all glass version with 3 or 4 gallons of resin, then it will weigh in a bit lighter than the wood version.

I don't mind building a throw-away plywood mold with nice rounded corners and high gloss paint with release agent on it - let's throw in an air connection to blow it out of the mold when it's done (flat bottom).

What I'm trying to figure out is a polyester lay-up for it. Do I need mat between the layers of cloth?

Would 3 or 4 layers of 6, 7-1/2 or 10 oz E cloth be good enough or should I throw something else in there for some increased rigidity? It seems like a 36 inch wide flat bottom would need something.

I've got an older book that really pushes mat, but from my limited experience, mat is a resin sponge! Can one do a layup without the mat in there? is it necessary to help keep the other layers saturated during set-up/curing?

What about incorporating S cloth or carbon cloth for stiffness.

Does anyone have any suggestions?

[alan white]

Building from glass will probably be heavier. You can use plywood to better (lighter) effect. It will require some close attention to structural issues including hull thickness but you would have to start getting more exotic using glass way before getting exotic with plywood construction.
Lighten the frame and scantlings of the original by eliminating stringers and stem, thin coaming, etc., etc..
Consider doorskin plywood for the deck. Maybe 4mm ply for the hull.

[Rich M]

Thanks, Alan. I was told the same thing about the core cell, keleg-cell, foams.

The weight is mainly from excess resin, I don't know enough to do the vacuum bagging and such. Don't really want to know.

As strange as it may seem, the door skins around here are backed with fiberboard/pressboard and weigh a ton.

I'm starting on another one and will try to use lighter wood and less resin.

[hoytedow]

Check the Intercity Lumber website.:

http://www.intercitylumber.com/Marine_Plywood_Page.php

[hoytedow]

Nice boat, by the way.

[Rich M]

H,

Thanks for the link & the compliment!

R