Curious- base coat vs acrylic urehane for base

You do not want to use super fast reducer. You want to use slow reducer and hardener in the hot weather. Slowing the process down allows for the material to flow longer rather than dry up and orange peel. If you use fast reducer/hardener in the hot weather, it may actually dry when spraying and result in a dry/flat looking finish or even the worst orange peel you can imagine - ask me how I know LOL