Re: insulation

["Mr. Joy Hansen" <joytbrew@xxxxxxxxxxx>]

Hi Doug,

Like your '67, my '69 Safari has urethane foam. As you know, the trailers
are flipped upside down at the factory during manufacture and it's a simple
matter to spray foam on the plywood. Unfortunately, when you begin floor
repairs and other activities inside the belly, the foam must be removed.
Also, under the normal circumstance, the foam deteriorates after a number of
years. I've yet to determine a way to use contemporary foam insulation 
in a can to replace the removed sections. Best I can do is to use a support
close to the floor, like Styrofoam insulation and spray the urethane
insulation in between to make a sandwich. Otherwise, I'd just use fiber
glass bats, preferably the block type as I don't think the roll stuff is
worth using in the belly. Vermin really tears it up and in a short while,
it's all down against the belly and holds the water against the
frame/outriggers, etc. as in my '74 Argosy.

You'll note that polyurethane foams were used in the late 60s for home
insulation, right up to the time someone found out that high levels of
formaldehyde were released from the curing foam. Formaldehyde can cause
many health problems and blindness is one pretty important consideration.
Don't know the properties of modern urethane foams. The glues and paints
are super tough and should have a place in Airstream restoration. 
Anyway, the formaldehyde problem forced it's ban for in-place foam home 
insulation (would carry to travel trailers). Don't think it was a Canadian thing, 
just a passing phase of Airstream construction.

Regards, 
Joy