1. Order up biscuits
If you plan to use biscuits regularly, a dedicated machine makes the process easier and faster.
No biscuit joiner? No problem. You can create biscuit joints on your router table using a 5⁄32" slot cutter [Source]. In the example shown in Photos A–G, I'm adding solid edging to a plywood shelf. Photos H–K show how to make end-grain cuts, such as when joining a rail to a table leg.
Locate the center of the bit by sliding a piece of scrap against the fence and the body of the slot cutter. Trace the end of the board onto the tape, marking both sides of the bit. Find and mark the center by dividing the line-to-line distance in two.
On the shelf, mark the center of each slot on the bottom (non-showing) face. Then add lines to the left and right, spaced half the Elongate Slot dimension. Align the left line with the cursor and plunge the workpiece onto the spinning bit.
Cursor line Clamp to the fence a cursor board with a line perpendicular to its edge. Align the cursor line with the bit centerline, positioning the board high enough so your material can just slip under it.
Set the depth of cut based on the size of the biscuit you’ll be using (chart above). Then set the bit height to center the biscuit slot on the shelf. I use brass setup bars [Source] make these adjustments quick and precise.
Move the workpiece until the right line aligns with the cursor, and pull the board straight away from the bit. Repeat the process for each slot.