John Deere Blitz Black

I first shot bc//cc on a project back about 1990. I have used single stage acrylic urethane 99% of the time since. Other day I called some PPG store to price a certain color. They will ask for my "number" and I just say I am an individual not a shop but you better give me the shop price/ The "kid" had to ask his boss for the price and it was like stupid low fr the paint and hardner. I called another store and asked did that store price and they siad it eas an industrial and called it maybe poly some enamel. I really have to wonder IF this is a good CHEAP paint for those that want to save money shooting darn tractor paint or rusteolum for top coat!! NOT me. but I see guys all the time wanting to save a few bucks.
I use Rusreolum for floors and bottomof carnew metal, Tough but what is the UV rating where guys use it for topcoat?