"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in message
. 3.70...
(snip)
On the comment about failed silicone -- yes, that might be it. I wish I
knew how to cause it to fail in just that way (if that's the case),
because it is a superior window-to-steel-door sealant in that condition.

LLoyd

I think different types of silicone are sensitive to different things, but
the usual culprits are sulphur compounds, oils, and amine compounds. you
could experiment with some things.