I have read a couple of posts relative to Castaldo Liquacast and
although I found it to be easy to work with, the molds just don’t
last in this humid climate. Urethane likes to revert over time and
the molds end up stuck closed. Storing in poly bags helps for a
while, but poly breaths, so moisture still gets in.
Akron RTV by Zero-D Products is a silicone. As such, it costs more,
but is permanent. It is clear and just the right firmness. The tear
strength is amazing. You will need some method to vacuum the mix
though.
You can get this product by calling 800-382-3229 or 440-942-5005. fax
is 440-942-2130. Good luck! Craig M.