I used the vinyl that you put on your windows to keep the cold out (I know it has a name, can't think of it.) I have to remember to take the tool box off my machine before I start-usually don't remember then have to slide the insulation board out of the way to get to it. I just taped the vinyl real tight on the bottom-wrapped it like a present. I think a shower curtain would work if it's shiny and slippy (is that a word?). Good luck-let us know how this works for you.