Hi Jeff

 

There are two ways to check the life of epoxies.  The first is to very precisely check the gel time after mixing to make sure it is within the specs.  The second way is to do a Shore hardness test.  Ther are labs that can do that or maybe you can talk to the folks at Hysol or maybe Jeffco into doing it for you.  Generally speaking, the real shelf life of epoxies are very VERY long.  Some of them also go through a phase change if you get them chilled sufficiently and need some warming.  So if you have some hardened resin that you didn't cross link, place the container under a black tarp in the sun on a hot day or place it in very hot water for awhile to resurect it.  That phase change does not really affect the properties.

 

Dan Newland