Brian,
I would go w/ the NP-1 urethane. Have used it for many years in the
curtain wall environment. Paints over fine in my experience. Sealants
that say they are paint overable are not all equally so. As to
'reversible' sealants are temporary/sacraficial materials intended to
have a limited durability -- though chemical science keeps extending out
the durability and desired performance characteristics. I don't see
reversability issues in the sealant question unless one is wanting to
use heritage sealants for a specific reason of authenticity. As to the
Sherwin-Williams product if they provide a full system warranty then
consider it in the evaluation.
Now, other issues my consultant friends out of Dallas always spec
silicones (and Chemrex-Sonneborn has a hybrid urethane-silicone sealant)
because in their experience urethanes melt out of the joints. Problem w/
silicones is that they are not usually paintable.
As to SWI... got friends who are members but have never been inclined
myself. John Bridges is both in APT and SWI.
][<en
--
To terminate puerile preservation prattling among pals and the
uncoffee-ed, or to change your settings, go to:
<http://listserv.icors.org/archives/bullamanka-pinheads.html>