How to Make Biscuit Joints Without a Jointer

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Biscuit jointers have a guide mounted on the front of the tool that allows you to cut a perfectly sized and shaped slot no matter what biscuit you are using. There’s no denying that using the best biscuit jointer is a convenient way to make biscuit joints, but you can achieve the same result with a router, or by switching to dowel joints. This article will explain further how to make biscuit joints without a jointer.

What Are Biscuit Joints?

Biscuit joints are invisible joints that can be used to connect two boards. Biscuit joints have a variety of applications, from edge-to-edge joints for making tabletops to mitered corner joints for picture frames.

A man holding a biscuit joints

A biscuit joint consists of two slots – one on each piece of wood. A small disc of wood called a biscuit is inserted into the two slots and glue is used to secure the joint. The boards must be clamped together while the glue dries.

There are three standard sizes for biscuits:

  • #0 biscuits measure 5/8 inch by 1 3/4 inches.
  • #10 biscuits are 3/4 inch by 2 1/8 inches.
  • A #20 biscuit is 1 inch by 2 3/8 inch.

Can You Make Biscuit Joints Without a Jointer?

Using a biscuit jointer will make short work of your project. But, if you don’t have one, you can make biscuit joints without a jointer if:

  • You have access to a router and a 5/32 inch slot bit equipped with a bearing.
  • You are joining boards edge-to edge.
  • The corner of the board is square, not angled.

If your joint doesn’t meet these criteria, you can use a drill and a jig to create dowel joints instead. See the guide below for details.

Use a Router Instead of a Jointer to Make Biscuit Joints

A properly equipped beginner router can easily cut slots for biscuits. You can use a router in place of a jointer.

  1. Gather your materials. You need a router, a 5/32 inch slot bit that has a bearing, a pencil, the two boards you’re joining, a package of biscuits, wood glue, and clamps.
  2. Mark the joints on the board. Arrange two boards you’re planning to join on a flat surface. Draw a line across the seam of the two boards in the locations where you want your biscuit joints. Mark the location of the end biscuits first. Space the joints evenly between the two ends.

The end biscuits should be about three inches from the end of the plank, with another biscuit placed about every six inches or so.

  1. Attach the bit to the router. A slot-cutting bit is designed to cut into the edge of boards.
  2. Set the depth of the cut. The biscuit slot on one side of the board must align perfectly with the biscuit slot on the corresponding board. Find the center point of your board and set the cutting depth of your router to that height.
  3. Clamp the board. Line the board up with the edge of your workbench and clamp it down. This will prevent the board from skittering away when you rout the biscuit slots.
  4. Cut the first slot. To cut a slot, place the foot of the router on the face of the board. Turn the router on. When the bit is fully inserted, guide the router first to the right, then the left, keeping the foot firmly on the surface of the board at all times.

The finished slot should be about half an inch longer than the biscuit.

  1. Cut the remaining slots. Repeat the step above on the other piece of wood. To keep your slot-cutting accurate, make sure to keep the face of the boards facing skywards throughout the entire process.
  2. Add glue. Squeeze wood glue into each of the slots and along the edges of the boards.
  3. Assemble and clamp. Insert the biscuits into the slots and assemble the joint. Firmly clamp the boards together until the glue dries.

Replace Biscuit Joints With Dowel Joints Instead of a Jointer

Dowel joints use a cylinder of wood and glue instead of a biscuit. They are also strong, invisible when finished, and can be used to support other kinds of wood joints.

  1. Assemble your tools. For this method, you will need a block of wood, some plexiglass, a ruler, and a pencil. You’ll also need a drill or a basic drill press with a standard bit set, and two screws. Small dowels can be purchased by the bag in various lengths and diameters.
  2. Select an appropriate block of wood. The block of wood that you choose for the body of the jig should be thin enough for your drill bit to pass through, but thick enough to support and guide the bit to make a perfectly even tunnel. Six inches is a good length. The jig must be wider than the thickness of the boards you are jointing.
  3. Make a guideline. Make a mark on the face of the block of wood at the same height as the mid-point of the boards you are joining. Extend the mark across the face and down one of the edges.
  4. Drill a hole through the woodblock. Use a drill press or a handheld drill. The size of the hole should match the diameter of your dowel. Line the center of the drill bit up with the mark on the woodblock. Drill straight through, then back out smoothly.
  5. Cut and attach the guide to the woodblock. Making your jig out of plexiglass allows match up the joint markers on your board with the guideline on the jig. Stack the guide on the edge of the woodblock, overhanging by several inches on one side to create an L-shape. Use screws to attach the plexiglass guide, drilling pilot holes if necessary.
  6. Mark the boards. Position the boards and mark the location for the biscuit slot on each piece of wood. Clamp the board to the edge of your work surface.
  7. Use the jig to drill holes. Place the jig on the board and align the mark on the board with the guideline on the jig. Guide the drill through the jig and into the wood to make a hole for your dowel.
  8. Glue. Place glue in the holes and along the edges of the board. Insert dowels into the holes. Assemble the joint and clamp until the glue dries.

Conclusion

If you don’t have a jointer, you can still make biscuit joints with a router. This method only works on edge-to-edge joining of square-edged wood. You will need a 5/32 slot-cutting bit with a bearing to complete this project.

Ellenkate grew up on job sites run by her family’s construction company. She earned her theater degree from The Hartt School, a prestigious performing arts conservatory in Connecticut. Her design and DIY work from her Chicago loft was featured in the Chicago Reader and on Apartment Therapy.