To use the clamping jig, apply glue to the mitered ends. Now you can lay the two pieces on the base with the mitered edges pointing toward the bottom edge of the jig. Be sure to carefully center these pieces on the T-track. Next, slide the inside clamping block against the workpieces and tighten the knob. Then move the outside clamping blocks into position and clamp them in place with a bar clamp. For maximum pressure, position the bar clamp near the base of the clamping blocks. Now just let the jig hold the pieces in place until the glue dries.