How to Join Two Pieces of Wood

Joining two pieces of wood is the most basic of woodworking tasks. There are many ways to join wood together to make corners or wider boards. In this article, learn about different ways to make wood joints out of two pieces of wood. 

How to Join Two Pieces of Wood to Make a Wider Board

Below are step-by-step instructions on how to make edge-to-edge butt joints, tongue and groove joints, and biscuit joints.

1. Edge-to-Edge Butt Joints

Edge-to-edge butt joints are the quickest way to make a wider board. 

1. Match the boards. Before milling or machining, look for two boards that share similar grain patterns. Decide how to orient them to best feature the characteristics or interesting patterns in the wood. 
2. Smooth and even the boards. To get a good, strong joint, it’s important that the wood pieces are the same thickness. The edge where the boards will be joined should be sanded completely smooth. You can also use a jointer plane to even the thickness across the boards.
3. Glue. Use a generous amount of wood glue on both edges of the two boards, and press the edges together. 
4. Clamp. Tightly clamp the boards together. The surfaces of the two boards must remain in close contact during the drying process for the glue to hold. Wipe up any excess glue after clamping the boards. 

2. Biscuit Joints

Biscuit joints use inset discs of wood biscuits to create a stronger version of edge-to-edge butt joints. 

1. Buy biscuits. Bulk bags of pre-cut biscuits are available at any hardware store or home improvement center. 
2. Mark the location of the biscuit joints. A 12 inch space between biscuits works well for most projects. You can increase the space between biscuits for thicker lumber. 
3. Use a plate jointer to cut slots in both boards. A plate jointer creates an oblong hole in the wood. These slots will hold the inset discs. Slots for single-row biscuit joints should be cut at half the thickness of the board. Slots for double-row biscuits should be cut at one third the board’s thickness. Set the plate jointer to the appropriate depth. You can also use a biscuit joiner.
4. Glue the biscuits in the first board. Clear the dust out of the biscuit slots. Fill the slot about one-fourth full of wood glue. Insert the biscuit into the slot. 
5. Mate the board. Put a small amount of glue on the edge of the second board. Be careful not to use too much, as you don’t want excess glue on the surface of your wide plank. Fill the slots on the second board about one-fourth of the way with wood glue, and insert the first board into the second. 
6. Clamp. Tightly clamp the two boards together until the wood glue is completely dry. 
7. Sand. Sand the surface of the joined boards so they match perfectly. 

3. Tongue and Groove Joints

If you don’t have a biscuit joiner, but still want a strong connection, opt for tongue and groove joints. Tongue and groove joints are stronger than simple butt joints or biscuit joints. 

1. Cut a groove in the wood along the entire edge of one board. A table saw is the simplest way to cut a groove, but you can also use a router with an appropriate jig. 
2. Measure and mark the tongue. Line up the two boards and mark the dimensions of the groove onto the second board. Use a table saw or router (not a jointer) to cut away the excess wood, leaving a ‘tongue’ the same width and depth as the groove you cut in step one. 
3. Glue the joint. Apply quality woodworking glue to the tongue. Insert the tongue into the groove. 
4. Clamp and dry. Tightly clamp the two boards together until the wood glue is dry. 

How to Join Two Pieces of Wood to Make a Corner

In this section, I will give you step-by-step instructions for two kinds of corner joints; dovetail joints, and end-to-face butt joints. I’ll also briefly review some alternatives to these kinds of joints. 

End-to-Face Butt Joints

Butt joints are the simplest way to join two boards to form a square corner. 

1. Glue. Apply wood glue to the end of the first board or the edge of the first board (to make a wide plank).
2. Assemble. Place the glued end on the face of the second board.
3. Fasten. Drive fasteners (nails or screws) through the second board into the end of the first board. 
4. Clamp. Clamp both boards to hold the joint tightly in place while the glue dries. 

Dovetail Joints

Dovetail joints are a type of interlocking corner joint that help wood resist pull force. They are commonly used on drawer fronts for this reason. No fasteners are required to secure dovetail joints.

1. Measure and mark the tail board. Tails are rhomboid-shaped recesses in the board end. Use a dovetail template, straightedge, and ruler or measuring tape to trace the tail pattern on the end of the board. 
2. Route or chisel the tails. Use a router fitted with a dovetail bit and a specialized dovetail jig to remove the wood from the outlined tails. You can also use a table saw to make dovetail joints.
3. Measure and mark the pin board. Use the tail board to trace the pattern for your pins onto the second board. 
4. Route or chisel the pins. Pins’ are rhomboidal protrusions on the end of the other board. Remove the excess material from the end of the second board, so that only the pins remain. 
5. Glue the pinboard to the tailboard. Apply woodworking glue to the pins and tails and slot the two boards together. 
6. Wait for the glue to dry. You don’t need to clamp a dovetail joint, but you should let the glue dry completely. Wipe up any excess and wait 24 hours. 

Alternatively, you can use a good dovetail jig to make the process a lot faster.

There are three different kinds of dovetail joints.

Through Dovetail Joint

When the joint is a design feature, a through dovetail joint is used. In this joint, the tails are cut all the way through the board, so the dovetail design is visible from both sides of the corner. 

Half-Blind Dovetail Joint

To hide the dovetail joint on one side, use a half-blind dovetail joint. Instead of cutting all the way through the board to make the tails, one face of the tail board is left intact. This requires more precise routing than a through dovetail joint. 

Sliding Dovetail Joint

A sliding dovetail joint involves cutting a single half-blind tail across the surface of one board, and a single pin at the end of the other board. The pin slides into the tail to join the two boards together. Because of the shape of the pin and tail, the boards will resist being pulled apart.

All of these cuts are made easier when you use a woodworkers dovetail saw. 

Alternative Corner Joints

Below are three alternatives to the corner joints described above. 

Box Joints

Box joints are a simplified version of dovetails. Instead of interlocking rhomboidal pins and tails, box joints connect two boards through square or rectangular teeth cut into the board ends.

It’s not as attractive or strong as a dovetail joint because the square shape doesn’t resist pulling force in the same way. However, it is a sturdy joint that requires no fasteners or glue. 

Mortise and Tenon Joints

A mortise is a recess cut into a piece of wood. A tenon is a square or rectangular protrusion carved out of the end of a board. These joints are not recommended for beginners, as they require a high level of precision. However, mortise and tenons joints are the strongest corner joint. 

Miter Corners

To make miter corners, the ends of the boards are cut at an angle other than 90 degrees. They hide the end grain of the wood and make a more attractive joint than traditional butt joints. 

Also see how to join two boards together lengthwise for other projects.

Conclusion

Joints are used to create corners or wider planks out of two pieces of wood. Simple joints can be achieved with wood glue. More complicated joints are usually stronger. There are many different kinds of wood joints, including; butt, biscuit, tongue and groove, dovetail, mortise and tenon, and box joints.