These are not the easiest of clamps for one person to use. I'd need an extra pair of hands to line everything up and there's barely enough room for a 3/4 inch thick board. The pressure point is also on the slide mechanism, so it's quite difficult to line up the miters. Eventually I gave up and threw them in the trash. I would just buy a set of metal clamps with a screw lever to tighten if you want to mount something at an angle.