The black stuff on the Burb is SPI, which I don't use anymore. Too tough to get and a lot of waste because of my spraying procedures. Which is, spray now, wait a few months, spray something else. By then the activator is ruined by the atmosphere, even when I store it in the fridge. Tamco has an extremely long shelf life! Even stored at room temp. I'm still using the DTA (Direct To Anything epoxy) that I bought at the beginning of summer! With no ill effects.
