I was like the lone negative reviewer on Amazon for that product for a while. I got a few hateful comments. I talked about it elsewhere and and despite following the instructions implicitly and having background in the use of two part urethanes and the analysis of them I was criticized for saying anything negative about it. I even bought a different can from another source and had the same issue. I think for the most part it is likely that there was an issue with formulation for a brief period of time. Others have had a lot of success using it. It was summer and I painted in a tented area outside. The humidity was checked to make sure it was low enough, but even so that might have had a deleterious effect on the cure rate. The problem was three weeks went by and the stuff was still soft, very soft. Movable with your finger soft. The ratio of A/B block was likely off and whatever catalyst they used was not promoting polymerization sufficiently. Needless to say I was pissed. Roth has some great stuff though. It is worth the cash if you want to get a great flake and don't have a gun and compressor.
If you want to do flake on the cheap I highly recommend Krylon Glitter Blast with a Fusion overcoat. Fusion is a great workable 1 part clearcoat. Sands easy and goes on nice with a very durable finish. Also builds really well on successive coats.
View attachment 3776442 This is Glitter Blast with Fusion.