Hi all, This Irwin clamp has stopped working because the serrations on the side of the vertical silver bar have become blunt. It’s a bit disappointing because it’s not had a lot of use. Is there any way of re-sharpening the serrations? I did think of drilling a few holes between the steel bar and the movable bit of the clamp to lock it in , with a locking pin or bolt, but it’s a bit of a Faf. Any other ideas?