Well it's me again with the inside part of my barn project. On these inside walls the owner wants to use an oil based Deft interior / exterior polyurethane.. My best advice from a PPG rep is to spray on the first coat. Let it cure for 24 hrs then pole sand the whole thing with 120 -220 grit (I'll be using 180). Then apply second coat. Any advice on back rolling this or what kind of roller cover to use? I'm all ears.