High density foam kayaking building

On Guillmot Kayak’s web site there is some sketchy info on the above. Search Dean Snow to find it. Does anyone know how to get more info on this?

Belton, this is the stuff I was talking
about … send me your address and I will send you a piece.

What is it?
If this is about the foam-strip Mystery shown on the Guillemot website, I would love to know the name and source of the material as well. I will be prototyping this spring and am searching for quick-build materials.

Thanks, Carl

I would also be interested in the name and manufacturer of foam strip suitable for prototyping. Thanks. Rusty

I’ll pass this info on when I get it.


These guys say their Divinycell product is appropriate for kayak building, but it isn’t cheap.


You beat me to it
I just spent quite a bit of time reading data sheets for density, strength info, etc. on a bunch of different products. Klegecell is a mystery material that I can’t find a supplier for. Noah’s has a page on it, but only sells something called Core-Cell, which apparently isn’t good for bending. I finally zeroed in on what looks to be the superior product, which is Divinycell H sold here:


It looks like the H80 (5 lbs per cubic foot) is a good choice, and 3/8" is probably a good thickness, which is what the Mystery is made from. A 3/8" sheet is $82 and is exactly 1 cubic foot, so would weigh 5 lbs. Assuming you need 2-3 sheets to make strips for a sea kayak, that means the core material for the boat would be between 10-15 pounds, plus glass or carbon, resin, etc. Cost for the core wouldn’t be too great if the prototyping goes really quickly. I wonder how well this stuff would bend around forms in strip building - the tech data is available here:


Anybody here used this product before?

Works perfect and is more consistant

Easier to cut / sand … with hand tools.

Dust falls straight to the floor.

Faster and more precise (IMO) to fair.

Heat formable too … vacuums perfect as well.

VERY high HDT and cyclonic life.

I never understood why more people don’t use it for strip builds.

Get a small piece and put a couple plys of your choice or reinforcement over it … you will be amazed @ how stiff and strong it is.

Sounds good

– Last Updated: Jan-11-08 9:27 PM EST –

Well the material sounds very good. I'm testing a 1/4 scale sof model, and it's working well enough to scale up. I might start by doing another model in foam to see how it works.

It would be nice if the 3/8" material could be parted with a knife or a hot wire to save kerf waste from a table saw.

Any advice on the best/quickest adhesive to stick the strips together? Or can you just pin them with toothpicks and let the fiberglass and resin do the glueing after the skin goes on?

Because you can heat form it, this
would be something cool to use for SOF ribs too … Right Greyak ? Come on man … someone has to do this. The whole frame can be bonded together.

Heat form the ribs … no kerfing ness. glass or carbon over, trim and build / install.

Dean Snow’s process?
Just looking to see if I got it right on what he did.

  1. Built a female mold
  2. Laid his foam strips into that mold in a stripper like technique.
  3. Glassed (and carbon) the inside of the foam.
  4. Pulled each of the foam and glass halves of the boat out of the molds and then bonded the two halves together.
  5. Reshaped a little bit of the exposed foam that is now on the exterior of the hull.
  6. Glassed over the exposed foam making the hull a glass-foam glass sandwich construction.

    Do I have this right?

I’ve built a few

– Last Updated: Jan-12-08 11:10 AM EST –

aircraft, using foam-cored composites. This is std practice in the homebuilt aircraft industry. Fiberglass sandwich construction in the AC industry started out with wood (balsa) core constuction, then advanced to foam.
Suitable foam is available in everything from foam sheets, to strips, to hot-wired blocks. Take a strong look at PVC foam as a core. It comes in all the aforementioned shapes, is super-easy to shape and cut (it's not at all squishy, but rather is hard, yet thin strips bend more than wood strips), and just loves epoxy and fiberglass.

Construction method
I’m planning to use the foam in a standard strip build method, i.e. stripping over bulkhead forms. I’m thinking maybe I’ll use 1" thick foam for a few of the forms and glass them in place, giving a series of watertight compartments. The female mold method looks OK, but I’d want full access to the hull exterior to make sure the strip seams are tight.

I sent an email to the manufacturer (DIAB) to find local distributors. I also asked them what would be involved in getting strips directly from the factory - I suggested 3/8" by 1" strips - I’ll post whatever response I get.