Joinery is a key step in a woodworking project. But as a beginner woodworker advanced joinery is hard! Instead focus on mastering these simple wood joints.
It’s happened to me before that after gluing up a project and thinking it was done, it fell apart the moment someone went to use it!
Using the right joint is key to a long-lasting item. And if you are a beginner, don’t try complex joints until you’ve done a few projects and become more confident of your skills.
The key to any joint is to maximize surface contact. What makes a glued joint strong is when you can increase the surface area of the glued joint.
So let’s look at the 4 joints that you can make.
The simplest woodworking joint you can make is what is called a butt joint. Literally this means butting up two pieces of wood and gluing them together.
This is the weakest joint and you should only use it without any reinforcement on small projects that don’t see much handling.
The weakest style of butt joint is when two pieces of wood are joined end grain to end grain. End grain has a tendency to absorb glue faster than the glue can bond the two pieces of wood together. You can use the trick of coating both end grains with glue, letting it dry and then using another coat of glue to glue the two pieces together.
A better butt joint is when you glue end grain to the long grain. Then you at least have one piece that glue won’t absorb into as much. Treat the end grain piece the same as above by coating it with glue and letting it dry.
The strongest butt joint is when you glue two pieces of wood side by side or face to face, so only long grain makes up the joint. This butt joint may not need any reinforcement although often some form of alignment aid is used. This type of butt joint is most often used for gluing up tabletops and other large slabs from individual boards.
The key to a strong butt joint are straight joints. These can be achieved by making sure all of your sawcuts are straight and at the right angle. When edge gluing for a table top you need to make sure that the long edges are perfectly flat. For this ideally you need a jointer although there are ways to joint an edge on a tablesaw or the old standby, a good sharp hand plane.
A lap joint’s strength is in the huge surface area that is created. You’re essentially taking what would be a weak end grain to end grain or end grain to long grain joint and converting it to a surface to surface joint which is much stronger.
Lap joints can be created at the ends of boards or can be created in the middle. They are usually made face to face.
While the above examples are at right angles you can also use a lap joint to join boards end to end. But not that common of a practice.
A lap joint is relatively easy to create, especially if you have a table saw with a dado blade. A router would work too with a straight bit. It is also an easy joint to make with a backsaw and a chisel.
This is the traditional joint for shelves. By cutting a dado into the side of a cabinet, you provide a strong slot to slide in a shelf or divider.
Like a lap joint it provides more surface area for glue and doesn’t rely on just an end grain to surface grain joint.
The other advantage of a dado joint is that the shelf sits on top of a horizontal surface (the side of the dado) which helps to support it. On the other hand an end grain to surface grain butt joint in the Butt Joint section above relies solely on the glue and any reinforcement you add. This puts great stress on the joint, especially if you put heavy items on the shelf.
Dados are essentially very narrow lap joints so the same cutting techniques can be used as with lap joints.
A groove is similar to a dado in that it is cut along the grain. Usually used on the bottom of the sides and ends of a drawer to capture the bottom of the drawer box.
A rabbet is essentially a dado along the edge of the board rather than across a board. It has the same benefits that a dado or lap joint have – a greater gluing surface.
Rabbets are often used to add a back to a cabinet. Or to connect the sides and ends of a drawer.
Like a dado they can be created using a table saw or router. If you are looking at using just hand tools, a rabbet plane makes the best rabbets, although it does take longer than other methods.
Unlike traditional joinery such as dovetails or mortise and tenon joints, these simple wood joints can benefit from additional reinforcement to lock them in place and not rely solely on the glue used.
There are a few options for reinforcing a joint:
Dowels – these require precision drilled holes in both pieces being joined. They can either be through-drilled, which means you will see the dowel on the outside of the joint, or as in the image below, blind dowelled to hide the presence of the dowels.
Pegs – these are similar to dowels but are considered a design feature of the project as they are fully visible and stand proud of the surface of the wood. Often used in Shaker furniture.
Screws – this is usually the strongest reinforcement you can add. Pre-drilling the holes is crucial to avoid any splitting especially at the edge of a piece of wood. Usually you should countersink screws to make them less visible or you can even counter-bore them so that they can be covered with a wood plug. Or use decorative screws (usually brass) as a design feature.
So the next step is learning how to make these simple wood joints, right? I’m working on a downloadable PDF to accompany this blog post that will cover how to create each of these joints using various tools. Once it is ready I will include a link to it here. If you want to be informed when the PDF is ready, sign up for the Pacific Coast Wood Crafts email list.