Oops. I too assumed the foamy stuff.
We used West System epoxy by the 50 gallon drums in our boat building shop. That kind of usage warranted WS to send a tech advisor around frequently. I still use West System exclusively (although in way smaller quantities!). A tech guy told me once that most all epoxy resins come out of the same spigot, figuratively speaking, that the differences between brands of epoxy lies mainly in the hardeners.