If it uses a catalyst then it's probally not epoxy but polyester resin and not as strong. Most epoxy resin comes in 2 equal size containers. Polyester resin has a short shelf life( found out the hard way) and when its past date it will not set up all the way but remains tacky. Never used the west systems but I have used Zpoxy for glassing and it works well. One thing I have been doing now is weighing out my epoxy instead of measuring. There's some great information on the Bob Smith website regarding epoxy and CA.
http://www.bsi-inc.com/
ORIGINAL: blvdbuzzard
I have some stuff Hobby Shack used to sell. This stuff was great. It has not discolored, still works and is some where around 10 years old. They had it on super sale so I bought 5 packs of the big bottles. I stopped getting the Tower or GP glues and epoxy after a few issues of the Ca going bad after 2 weeks.
Best and cheapest epoxy I have had was from a composite store. It was their brand and a full quart of resin and a 8 ounce bottle of catalyst cost just a little bit more then the 9 ounce bottle from the LHS.
Might look for a shop that sells fiber glass and carbon fiber. They usually sell the good epoxy and resins.
Buzz.