Crain Rubber Base GougeThe best tool for gouging out the back of rubber or vinyl base for tightly wrapped corners comes with a double tipped blade. The V tip makes a sharp V shaped groove that conforms better to tightly formed sheetrock corners. The U Tip makes a wider U shaped groove for fuller corners, or for a tougher base where a wider groove must be made. The depth gauge adjusts using a simple set screw.