Sawby: I have painted 2 school busses over 30 yrs. I used my high pressure barn sprayer. 4,000psi Hero. Anyway painted one with JD Green and another with Benjamin Moore Iron Clad oil base at 45 mph they both looked great. Also they were being used to haul hogs to the market.
I high pressure washed, wiped down with a cleaner put vasoline on head lights, taped off windows, shot right out in the barnyard. Hogs didn't care

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popcorn The Truth is Out There (if it don't move I'll paint it.)