Captain Tolley's Creeping Crack Cure is not a caulking,
but it will seal fine cracks or spaces arround windows, in
fiberglass
or any where you have a leak.
We had a fellow fix a expensive leaking dive watch and another fellow
use it
on his bar stools to take the sway out of them!
 
Captain Tolley's Creeping Crack Cure is a unique water based sealant

formulated to penetrate fine cracks.  It uses capillary action to set a 
clear, flexible and waterproof seal, and
finds leaks without dismantling. 
Compatible with most materials, including glass, wood and metal. 2 oz.