2. Trap bevel cuts even when your fence can’t
A few biscuit-joiner fences tilt to 135° to capture the end of a mitered workpiece. That keeps the tool stable when cutting the slot. If your joiner’s fence maxes out at 90°, you can get the same stability with this trick. Simply clamp your mating mitered workpieces back-to-back so the bevels form a 90° angle, as shown, and cut slots on each miter.
3. Reinforce too-narrow joints with back-side biscuits
The slot for a #0 biscuit measures about 21⁄8 ” wide, so you can’t hide a biscuit joint in stock narrower than this. If you’re making face frames—which are typically narrower than that—you won’t be able to join them with any of the three standard biscuits. Here’s a way to reinforce a joint with full-size biscuits on the back side—provided they won’t be seen. Glue and clamp the mating boards together. When dry, cut slots across the joint line no deeper than 2⁄3 the boards’ thickness, and then glue in biscuits (top photo). After the glue dries, cut the biscuits off and sand them flush.
If you make a lot of narrow face frames, consider purchasing Porter-Cable’s biscuit joiner, which includes an extra blade to cut smaller face-frame slots for special 1 1⁄4 “-long biscuits.