BASIC WOOD JOINTS
If you have any experience in woodwork you will know how important basic wood joints are and when constructing your projects. Although there are many different ways to join two pieces of wood, let’s skim through 9 basic joints that are particularly beginner-friendly in carpentry. These rely on some external source of strength such as screws, splines or glue.
1. Butt Joints.
These are just two pieces of wood attached perpendicularly to each other, often with nails or screws. They can be perfectly good joints. However, there will be no structural integrity on their own.
Butt joints can be your quick option when the work is rough or rustic or when speed matters more than looks. Just make sure your joining technique is right for the job (you might also need a metal corner bracket for extra strength, for instance). To dress up a butt joint you can either countersink or plug your nail and screw holes.
Pocket joinery is great for attaching wood pieces with different grain orientations such as table aprons and legs or for making face frames. You might use it to reinforce a butt joint. Because the screws are toe-nailed at an angle into the wood, the joint is much stronger than a typical butt joint where the screws go directly into the end grain.
Pocket joinery is fast and relatively strong, but you will need a special jig and drill bit. These joints are not the prettiest so you’ll want to figure out a way to hide them.
This method involves gluing wooden “biscuits” into slots cut into the wood. It’s an excellent way to hold together pieces of plywood or other engineered material, providing plenty of gluing surface as well as the strength of the biscuits themselves.
Biscuits are good for casework and for reinforcing and lining up edge joints, but layout can be confusing until you get the hang of it.
2. Miter Butt Joints
The mitered butt joint is basically your standard butt joint, with the edges mitered to a 45-degree angle. They have more glue surface than a straight butt joint — a plus. The two pieces of wood is fastened with nails or screws and allows for a very sleek looking finish. This joint is most often used for structuring roofs, frames and small boxes.
Thanks to the super strength of new glues, a small box made only with miters will usually hold just fine. Still, adding a spline is a good idea.
3. Edge Joints
Picture this: you need an 8-inch wide panel for your next project, but the widest board you have is only 6 inches. This is where the edge joint comes to the rescue — just by gluing the boards side-by-side.
I know what you’re thinking: Two boards glued along the edges can’t possibly be sturdy. But you’d be surprised by how strong this joint really is. If you try to break the board, the wood around the glue joint will break before the glue does. However, gluing wood fibers end to end makes the joint considerably weaker, so this should only be used to widen a board, not lengthen it.
4. Dovetail Joints
The dovetail joint is one of the strongest joints and relies on pure workmanship and very little glue; no nails required (the notches in the wood fit together like puzzle pieces). This joint is most commonly used in Furniture and Cabinet making, because it can sustain a lot of weight. The ends of the pieces (called tails and pins) interlock and make a solid joint.
Novices take note: this joint isn’t exactly simple — tight-fitting dovetails are considered to be a sign of a great woodworker. But even if you’re not well-versed in dovetail joints, even one done a bit sloppily can be very strong.
5. Mortise and Tenon Joints
The mortise and tenon joint is one of the oldest joints that are still used today and consists of one piece fitting into another. The mortise is a squared hole that is carved into the side of a piece of wood and the tenon the protruding piece that fits into the hole. This joint is known for its aesthetic beauty and is used for joining exposed beams. Therefore, it doesn’t need any glue or nails to keep its structure.
This joint might look like a butt joint from the outside, but hiding out of sight is a tenon (that is, a projecting piece of wood) that fits into the mortise (a recess) of the other piece, locking the wood together.
This method provides a lot of strength and glue surface. There are also many varieties of the mortise and tenon joint, including mortise and tenons that incorporate wedges or pins to lock the joint in place.
6. Dado Joints
The dado joint is a very simple joint; it joins together two pieces of wood by fitting one piece into the notch of the other and then fastening it with glue or nails. It is often used in joining plywood and the backs and sides of Cabinets and dressers.
One of the most common uses for the dado joint is applied in joining shelves. This method joins two pieces of wood with a groove cut into one board that a second board fits into.
7. Rabbet Joints
The rabbet joint is very similar to the dado joint, but instead of having a notch in the center of the board, it has one on the edge of it. Glue or nails are required to fit the pieces together tightly. This joint is most commonly used when two edges need to join tightly together, like doors and windows.
8. Half-Lap Joints
The half lap joint is used when two pieces of wood need to be joined in the middle, by notches cut into each one. This joint is one of the weaker ones and therefore you would need more than a small amount of glue to secure the pieces properly. This joint is used to create different types of frames and structures.
9. Tongue and Groove Joints
The tongue and groove joint consists of a slightly angled groove in one piece of wood and a tongue in another. These two pieces fit perfectly and lock together, meaning they can only be separated when lifted up at an angle (no glue or nails are needed). The most common use for this particular joint is to lay down floorboards.