a_pla5tic_bagYou should slide on pvc just fine... Is it really wide pvc and you're trying to grind on the frame and probably on the urethane wheels? If you're wheels that aren't antirockers or really hard urethane hit the pipe you're going to stick. And if you try that when actually trying to grind you're gonna go flying into the ground and all over the rail.
milk_manA PVC box probably won't work. Try a single pvc like 4 inches diameter
nico.ostranderMy box is 6, 2inch pvc pipes. I am only grinding the outside one like you would a ledge at a skate park