I've brushed POR-15 Chassis Coat Black (UV resistant) on the frame, under the cab, and inside fenders; and sprayed it on the running boards. In all cases, I've been very happy with the results. The stuff is tough and looks great. Although the can says nothing about temperature, I recommend applying it when the temperature is between 55F and 90F. I wasn't happy with the flow at temperatures below 55F. When spraying, I use 10% lacquer thinner with no problems. I also use lacquer thinner for clean-up with no problems. Buy it in quarts so you only open one quart at a time. You spend a little more, but it's worth it.
