Bulkheads on Strip-Built

Submitted byStephen Connelly onTue, 01/05/2021 - 09:55

Am preparing for my first strip-build and want to know whether I should be using foam or plywood for the bulkheads. Should I be concerned about the hull compressing and damaging it due to a plywood bulkhead resisting this compression?

 

Stephen 

Strip-built kayaks are pretty tough, I've always (11 kayaks) used either thin plywood or strip panels, and never had a problem in spite of some pretty good hits when rock gardening.

Foam bulkheads are much harder to glue in securely, take up more space and are not much good as footrests, if you are fitting the kayak just for yourself and using the front bulkhead as the footrest.

Justin

JohnAbercrombie

Wed, 01/06/2021 - 18:18

I agree with Justin's comments.

Wood-core hulls are extremely stiff, so the bulkheads don't add a 'stress riser' and don't make fracture more likely.

I use fiberglass panels for bulkheads in my boats - laid up with glass cloth and epoxy. When installed with epoxy fillets on both sides they are strong enough to use as footboards.

Recently I was working on a commercial glass boat that had fiberglass bulkheads that looked as though they were cut from commercial panels - a flat version of the corrugated stuff you see for roofing over garden sheds. One nice feature of fiberglass bulkheads is that they let a bit of light through which can be a good thing.

i have several strip builts in my inventory and half of them i did wooden bulkheads and the other half have minicell foam bulkheads.  no problem with either installation.

i do agree that working with foam bulkheads is a bit more work.....but i would not describe it as hard so much as time consuming.  becuase of the thickeness of the foam, there is a lot more measuring/test fitting becuase you really need to fit it in three dimensions vs a wooden bulkhead is realy only about getting the profile right in two dimension.  becuase of the tickness and position of the bulkhead behind the seat, you may also have to deal with interference with any through hulls/rigging aft of the seat.

i don't really worry that my kayaks with wood bulkheads are more likely to crack.  while i get the ideas from Nick's book i why you want a little flex, i just have yet to encounter a situation with my wood-bulkhead-boats that has led me to regret the decision.