devcon works best thinned way down. I can spray it out of a brush and cleans up great.....not many doing that
KBS or any other moisture cure urethane needs to be handled correctly for long shelf life. That said, it’s not that hard. I have had a quart of KBS on my workstation for a couple years using the “tap the can” method of dispensing and storing and it’s still good. Thin with xylene to keep it from gassing around your eyes where it tends to go on thickest and bubble just a touch.