When clamping boards to make a panel, pipe clamps can right up on the fixed jaw. Unnecessary pressure will make your wood uneven, and the panel will buckle. This is caused by the jaw’s angle changing as pressure is applied. To prevent this, use a draw with the same diameter as the panel’s thickness and place it between the jaws and the wood you’re working on. When you do this, pressure will be applied to the center of the panel edge where it should be.