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Old August 26th 03, 03:57 AM
Jeff
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Here is the quick down and dirty on foam....

When you are talking about building airplanes there are 2 basic types of
foam, polystyrene (blue, pink) and polyurethane (tan, white, yellow). What
you really need to know is that polystyrene foam can be hot wire cut and is
very susceptible to fuel. Polyurethane should not be hot wire cut since it
emits cyanide gas when burned, but it is impervious to fuel. Generally
speaking, polystyrene foam comes in big blocks for hot wire cutting wings
and the like. Polyurethane foam normally comes in sheets or varying
thicknesses (1/4" to about 1"). The foams will also come in various
densities in weight per cubic feet.

When you talk about blue foam or polystyrene foam there is the construction
insulation stuff and flotation billets. The construction insulation has a
very small cell structure and I do not think it would bond very well to the
fiberglass. The flotation billet on the other hand has a more open cell
that will bond well with the fiberglass cloth.

Hope this helps.

Jeff

"Corrie" wrote in message
om...
What's the difference? I see references to blue foam all the time - why?