At the encouragement of @ukswrath, here is a post I originally made a year and a half ago on the Anovos FB build group, which is handy for all makes of armor, not just Anovos.
ABS Paste?!?! WTF is THAT?
I've seen variations of this question over and over. So perhaps this will be helpful.
ABS paste is homemade glue for your ABS plastic. It literally melts and reforms the plastic into a solid piece, so it's more like welding than gluing. But