For repair garages in general, by electrial code, nothing that could create a spark is allowed below 18 inches, that's where gasoline fumes collect keep that in mind also, especially on old trucks with vented fuel caps. There is far more to the code than that and the amount of air exchange is a factor especially in a drafy barn, but are paint solvent fumes lighter than air? I once went to a body shop for some advise, a floor mounted gas furnace was running 10 feet from a guy spraying a panel.
