Canadian Canoe layup schedule

[cadmec]

Hi All,
if anyone can help it would be greatly appreciated. I have a 4.8 metre long x 0.8 metre wide canadian canoe 2 part mould (deck & hull), does anyone have a recommended layup schedule for a canoe of this size,(the bench seats are part on the deck mould). eg if i was to make the hull from 3 layers of 450g/m csm with polyester resin and the deck 2 layers of 450g/m and the shearjoint 2 layers of 450g/m on the inside only, would this be enough, or do i need woven roving or other product, as my experience has been only with 3.6 metre white water kayaks.
regards
Cadmec

[yokebutt]

Cadmec,

That should work I think, if anything, perhaps substitute a layer of mat with cloth. I wouldn't use roving, no fun forcing it into severe compound curves.

Mat is not the greatest structural reinforcement, but this type of boat shouldn't see all that much load, and since mat soaks up a lot of resin you get a lighter skin for a given thickness (density of glass is 2.55 and resin about 1.1) I would strongly recommend using a high quality resin with good elongation properties though, that would keep the skin from softening due to micro-fracturing, preferably vinylester.

Yoke.

[cadmec]

Hi Yoke,
i like to thank you for your reply, it has given me something to work with, and direction to do more research, thankyou.
Cadmec

[Dutch Peter]

I believe there is an article about canoes in the latest issue of Proff. Boat Builders. Will have a look if there's any mention of the lay-up used!

[jimslade]

Gel, 2 layers of mat 1 1710 bi glass 1 layer of cloth
the trick is to be light on the resin, a simple mistake that is done by many builders.

[cadmec]

hi jimslade,
sorry for my ignorance but i only know of 300 , 450 , 600 and 900 g/m sq csm, so is 1710 bi glass an imperial equivalent of 900 g/m sq, and any particular cloth weight?
thank you for your advice
cadmec

[jimslade]

sorry Im not sure of the conversion even though I learned both systems in school. All the suppliers in my area (toronto Ont) use the ounce system 1710 is a mid weight glass. Its 17 ounce of stiched glass with 1 ounce of mat attached. I think that 900 gram cloth would be the same as 25 ounce material. The mat I would use is 1 ounce. Sorry I cant help you out. You could try the NOAHS BOATS site on the web, they may have the conversion chart.

[marshmat]

For a canoe, I would not recommend more than one thin layer of CSM. Use the mat as the first layer against the gelcoat, and then the rest of the hull is best off being made of light cloth or veil- a few layers in the 200-300 g/m^2 range would be my selection (better two light layers than one heavy one, I find). This hull is designed to flex slightly in the bottom as it absorbs the waves. A continuous cloth can flex a bit to take this; CSM would be more likely to fail. If you can afford to buy bagging materials, I would strongly recommend borrowing a vacuum pump and vac-bagging the laminate as air voids in a canoe hull can be rather troublesome. If you're building it yourself, epoxy is well worth the extra $$ as it is far easier to mix consistently, and is stronger than poly- or vinyl-ester.