As my mortiser bits dull, they’re more prone to sticking in the mortise and harder to withdraw. There’s also the constant problem of shavings accumulating around the bit, obscuring the view. To remedy both issues, I made a two-layer custom fence from scrap. The rear layer is screwed to the mortiser’s cast-iron fence.
The front 1/4″-thick layer attaches to the rear layer with a pair of carriage bolts and nuts that fit in slots in the rear layer. That way, the front fence facing can move up and down, then lock in place to act as a hold-down over the top edge of the workpiece I’m mortising to keep it from lifting up. I also attached an old hose from my CPAP machine to the front fence with a scrap block, and it’s attached to my shop vacuum to suck the debris away.
– Perry Tornquist
New Braunfels, Texas