RE: SB: RE: Structural Insulatated Panels (SIP)

["Sigi Koko" <sigikoko@earthlink.net>]

My understanding is that all formaldehyde-based resins are water soluble by
nature, but those that are more stable (resorcinol, phenolic) last longer in
water conditions, but are still ultimately susceptible to water.  I have
certainly experienced delamination of exterior grade plywood and OSB, so
that seems to hold true in my experience.  (MDI resins, on the other hand,
are water resistant.  Such as those used in wheatboard, Medite, etc.  My
experience with these products is that they mold when exposed to lots of
water, but do not disintegrate.)

Hope this helps.
Sigi

-----Original Message-----
From: billc_lists@greenbuilder.com [mailto:billc_lists@greenbuilder.com]
Sent: Monday, November 26, 2001 11:49 PM
To: strawbale@crest.org; greenbuilding@crest.org
Subject: Re: SB: RE: Structural Insulatated Panels (SIP)


It's my understanding that phenol formaldehydes are the glues used in
*exterior* wood products (exterior ply, osb, etc), because they are *not*
water soluble.

Or is my logic wrong?  It's possible that exterior glues phenol
formaldehydes which are not water soluble, but other phenol formaldehydes
exist that are water soluble.

Can anyone clarify?  Thanks.


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