[BRENT in 10-uh-C]

Define "med reducer"? Are you saying DT860 DT870 or DT885, --and what temps are the air coming across the sheetmetal? Also, what kind of gun and what is your physical strength like? It can be painted all at once with a slower thinner however your 'stamina' needs to be there (tired hands, arms, & brain cause runs!!). No harm in spraying in stages if that is what it takes to get a slick finish.