I disagree. It takes hardly any time at all to clean out a paint gun. I end up using may 10oz of MEK to wash it out when I do. Takes less than 5 minutes to measure and mix with the dixie cups. In the end its cheaper to buy this stuff in a kit, then mix n spray than to do it with rattle cans, plus it being a 2 part, its chemically cured. If you had a 2 part epoxy in a spray bomb it would harden inside the can. I dunno, but I just dont trust epoxy primer out of a spray can.