<VV> epoxy question

[John McMahon]

Someone mentioned JB Weld, which reminded me to ask for clarification on a 
certain point.  I've heard that some "epoxy" materials are not really epoxy 
at all, but some sort of polyester or something.  I've used JB Weld in many 
applications, but there was one where it was exposed to gasoline, and seemed 
to be softening after a short time.  Is JB Weld really epoxy?  Is there any 
other similar material that would withstand gasoline better?

Thanks,

John McMahon
1965 Monza coupe