[TheForge] OT Urethane foam. was inflatable castle

[Jerry Frost]

----- Original Message -----
From: "Andy Vida" <osan@netlabs.net>
To: <theforge@mailman.qth.net>
Sent: Friday, March 19, 2004 11:41 AM
Subject: Re: [TheForge] OT Urethane foam. was inflatable castle


>
>
> Jerry Frost wrote:
>
> > Directing a foam into a suitable shape is easy enough, a double wall
with
> > ties between the walls to keep a proper thickness works fine. A spray
> > application won't work unless the conditions are ideal in which case you
> > wouldn't need a fast construction technique.
>
> Doesn't urethane give off noxious fumes such as formaldehyde?
>

Yeah it does. The new formulations however outgass way less than the older
varieties. We have 5" in the wall and 8" in the roof. We had it sprayed on
about 5 years ago and not only is it a higher R value it has initial
outgassing of less than 5% of the old type. It outgasses 98% in 48 hrs and
after two weeks requires forensic type testing equipment to detect
formaldehyde at all.

I recently heard they've developed a urethane with none at all.

There are also other types of spray foam though none with as high a R value,
expansion ratio and low weight.

Even so, as an emergency shelter one is much more concerned with surviving
till rescue arrives, usually less than 48 hrs. The shelter system I envision
would have a double wall with the foam injected between. An impermiable
inner wall and a semi-permiable outer wall would allow outgassing and
protect the occupants.

Frosty
------------------------
If it ain't forged
it ain't real.
Wrought iron is.
The FrostWorks

Meadow Lakes, AK.