: Hi All

: Well, the conversation below on floatation has me re-thinking my idea on
: floating my Walrus. Just thought I'd run it by anyway.

: I was thinking of useing the spray canned, expanding foam. It comes in two
: different types. A low expansion type, around 2:1 I'm told. Then there is
: a much higher expansion type. Amount unkown. I was thinking that when I
: have the hull covered, I could put some plastic or possibly masonite,
: waxed, into the bow and stern to form a mold the approximate shape of the
: empty cavity. Then, spray the low volume style around on the forms and
: forming a compartment. Letting that dry and removeing it from the forms,
: spraying ( a little at a time of the high volume foam into that and
: letting it fill. When done expanding to fill the form, then fit it back
: into the bow and/or stern cavity and use a little of the low volume foam
: sprayed between the block and the inner sides of the frame to glue it in.
: That way, it wouldn't interfere with the skin, causeing any bulges or
: stretching, or expand the frame out of shape in any way. Thought this
: might be a way to add floatation since there are no bulkheads,
: compartments or hatches to contend with. The Walrus is just a
: play/learning boat till my Great Auk gets done next spring.

: So, what are my choices? Same as below ?

: Rehd

Hi Rehd,

I am building a self designed Kayak similar to the Little Auk as my first and I probably won't have any hatched compartments for bouyancy, so I am going to keep your idea in mind. I orininally mentioned that I was thinking of pouring expanding foam into the bow and stern as floatation, but was warned that this might put too much pressure on the boat's structure and cause damage. I had worried about this also, because when I was in pattern making I once used expandable foam as an experiment to back up a pattern. I boxed the back with 1" plywood with 2" holes in it for the foam to flow through and not deform the square back, but it did anyway. This foam expandsion was probably 10 or 20 to 1. However, I think I recall mixing a batch in a gallon paper mixing container to see it's reaction and it only foamed up out of the container without deforming it in any way. If I remember this correctly, and I would run this test again before trying this on a kayak, then I have in mind, standing the kayak on its nose veritcally and making my pour through a garden hose with a funnel attached to the pouring end.

John