how would some one lay up fiberglass inorder to make a boat like a canoe or a out-rigger canoe?
Usually, with the help of a female mold, which should be pretty easy to vac-bag. I recently saw a 150’ yacht half-hull layed up and under vacuum. Very impressive.
7/10
You could shape it out of a big block of foam, glass it, then hollow it out and glass the inside if necessary.
I heard of a Japanese project where they shaped a yacht out of a foam block, glassed it, then carved in the cavities for cabins etc.
sounds like i will make a female mold out of the pink hodpo foam cover the inside with wax paper, prevent the epoxy from sticking.
well, its not a canoe. but it may give you some ideas.
http://www.ptone.com/Kayak/surfboat/building/shaping.html
later
A somewhat easier way might be to copy a hull that you like:
Coat the hull with mold release agent- wax and/or polyvinyl alcohol, glass over that quite heavily, adding wood reinforcements to the outside so it won’t warp in use. Pop it off the hull you’re copying, finely sand the inside and you’ve got a female mold that’ll work just fine.
This method, by the way, isn’t limited to copying fiberglass hulls, you can use it for copying wooden hulls too. Quite a few of the fiberglass boats out there are copied from a wooden original. Nor is it limited to use with polyester resin - use the right release agent on the mold and you can use epoxy with it just fine. But do make the mold using cheap polyester resin -
Should you wish to go from a hull shape of your own, you might find it easiest to wad together several layers of the isocyanurate insulating foam ( after removing the foil covering it has) with the adhesive of your choice, shape it, glass it ( this particular flavor of insulating foam works fine with polyester resin - it gets used for custom insulated fiberglass fish boxes, for instance ) and make your mold from it as described above.
You won’t be able to just go with a shaped foam mold, covered with wax paper. Or, perhaps you could, but chances are that you’d wind up sanding, fairing, adding glass where you wound up sanding through and so forth, to the point where it really isn’t worth it. A mold needs to be quite a bit stronger than just a few sheets of foam hung together somehow.
The additional time and expense of making a shaped hull form and a mold are compensated by having a shape you can see and work with rather than just shaping a cavity and hoping for the best and the lower cost of using ‘boatyard-grade’ polyester resin for the mold rather than expensive epoxy.
Besides which, if this is a consideration, molds do wear out or otherwise get past it. And if ya do it this way, you’ll have that original hull to make a new mold from or modify easily to make a new and different mold from, with no more than a bit more glass and maybe a little Bondo.
Hope that’s of use
doc…