On 30 Apr 2004 04:22:27 -0700, (Snowman)
vaguely proposed a theory
.......and in reply I say!:
remove ns from my header address to reply via email

OK. I am now on track as to how these things are built. Sorry about my
misguided attempts.

My feelings:

As has been saidKevlar would be a difficult material to use to make
ribs as you suggest. Try epoxy/glass.

I cannot see any troubles. Although the foam is softer than wood, the
glass (kevlar) skin is what makes a foam/glass frame stiff, and stiff
it would be. Make the "walls" heavier than the "roof (inner) and
"floor" (outer) skins. make the floor heavoer than the roof.

Having said that, if the bending is the problem, I still reckon that
you could use kerfed wood, to make it easier to bend, over an
armature. My trial methos would be kerf and bend with the kerfs inside
the cirve, so that the outer side, at first was fair and not blocky.
You would have to make enough kerfs, each kerf wide enough, to allow
the bend.

This would then be covered with the glass skin, as much as possible,
and then turned and glassed on the remaining side once dry. Careful
work and a fair bit of it. The advantage of using wood as a core over
foam is that the skins can be thinner without fear of have
easily-punctured walls.

In the end you would have to try a few of these and test the
strength/weight ratio of these vs straight (bent!G) wood. Strength
in this case to my mind would include some sort of stanadard crushing
test.

I still wonder if all this weight saving is worth the trouble....I can
see it being useful in extreme situations of portability, and careful
usage.

I'm looking at building a Geodesic Airolite Boat, (see www.gaboats.com
by Platt Monfort) but I'm considering an interesting idea and I'm
wondering what you all might think. Instead of using wood strips to
form the geodesic structure I am thinking about using foam strips
wrapped in Kevlar tape and epoxy.

I have been reading about the construction of these boats and found
that some people have trouble with bending the ribs to shape without
breaking, (and this is with better quality wood that I am able to
source). I'm thinking I can bend foam cores easily to shape and then
once assembled in a frame start wrapping it all in Kevlar tape,
forming a makeshift Kevlar tube frame.

I'm still considering using wood for the stringers and gunwales as I
can form those with little or no problem. Having the stringers and
gunwales constructed out of wood would also make forming the foam ribs
much easier as it would give me something solid to work the foam
inside.

-Does anyone foresee a problem with pursuing this type of
construction?
-How will Kevlar wrapped foam compare to the equivalent
cross-sectional wood piece in strength?

Thanks
Jordan Richardson

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