Drill and countersink two holes in each PVC piece, then space and screw them along a pair of 2-in.-wide boards. Attach the upper board to your shop wall and snap a pipe clamp in either end to ...

We also tried a PVC board along the bottom ... because it has a layer of wood to stain. All three materials swell when they become damp. Plywood generally shrinks back into shape once it dries ...