Break free from biscuit blunders

Mistake #2: Mating surfaces misaligned

If the mating biscuit slots you cut don't match up perfectly, the work-piece surfaces will not be flush, as shown at top left.

Solution: First, reference your cuts from the same workpiece surface (the top face). Second, don't use your joiner's base and fence together for alignment when cutting the slots; both might not make parallel contact, resulting in uneven slots. Instead, reference your cuts either with the base resting on the benchtop or worksurface, as shown at bottom left, or with the fence resting on the face of the workpiece.

Complete Guide to Joinery