composite construction, strip canoe plans
 

sebastian ) writes:

so i was going to make a bunch of 1'x4' kevlar sheets by pressing the
epoxy impregnated kevlar between two boards covered with polyethylene
sheeting to keep the kevlar from sticking (maybe park my truck on the
boards to really squish out the extra epoxy). then ill use these
semi-rigid kevlar sheets to cover the the canoecraft mold stations.
the comment about the spacing being too far may be valid but with
sheer and keel cords on the sections i might be able to fudge it.
with that first layer of kevlar sheeting in place (held together with
5min epoxy) then i was going to layup more kevlar cloth on top of the
semi rigid sheets (with slow cure laminating epoxy) so that i can have
3 or 4 layers of kevlar total. Since kevlar is fuzzy miserable stuff
as a external surface, and not that stiff, ive got many pounds of 12k
high modulus carbon fiber roving and i was going to lay up one or two
layers on the outside all running the lnegth of the the canoe for
stiffness and also carbon is nicer/easier to patch than kevlar and its
god almighty light which is what im shooting for i really want my 15'
canoe to be no more that 30lbs. so the end product canoe will be 4
layers of kelvar with 2 layers of carbon fiber. i figure with a nice
stiff gunwhale maybe out of carbon fiber tubing (which i found an easy
way to make by winding roving onto metal mandrel) and some support
beams it might not fold up on me.

sounds like a good plan. if the boat is flexible when you try it on the
water you can always bend in and glue down some ribs to stiffen it.

boats have been made out of flat fibreglass panels laid up beforehand. I'd
buy a roll of vapour barrier plastic sheet as it is cheap and stiff. I've
tried plastic garbage bags on small jobs but they wrinkle and leave a
rough surface. I'd also staple the plastic sheet to the surface of the
form to keep if from moving. Vapour barrier plastic should also be stiff
enough not to distort if you want to squegee the resin on the cloth before
covering the layup and weighing it down. Weight should be as good a vacuum
bagging in this situation.

however I'd be inclined to use long narrow layups. a pair of sheers should
be able to cut the thin panels into narrower strips.
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