Getting to Grips With Woodworking Joints
Now that we’ve had a good look at the various woodworking tools and how to use them, we can get started on some joinery. Woodworking joints are at the heart of the vast majority of projects. From cabinets and chairs to doors and boxes, wood joints hold everything together.
In this chapter, we’ll take a look at the many different types of woodworking joints, what they do, and how to make them by hand. From the beginner-friendly butt joint to the decorative dovetail joint, we’ll get familiar with all of the most common and useful.
We suggest making each of these joints using scrap wood to get used to the basic techniques.
What Is the Purpose of Joints in Woodworking?
In a nutshell, joints are used in woodworking projects to fix two pieces of wood together. They can be both functional and attractive and are employed to complete a wide array of projects. The strongest woodworking joints can take a huge amount of strain, supporting anything from a sheet of glass in a window frame to the weight of a person on a chair.
Here are some of the most common applications for woodworking joints:
Frames are the bread and butter of woodworking and they’re all held together by joints. From doors and chairs to boxes and walls, frames are everywhere and you can use a wide variety of wood joints to keep them together.
Solid Wood Boards
Building a solid wood board typically requires you to fix several narrower planks of wood together. The joint you use to do this can alter the finished product by making it more decorative, stronger, or simply quicker and easier to put together.
Need a longer plank? A number of woodworking joints will get the job done, and create a strong finish that’ll last.
Some joints are stronger than others, so depending on the type you use, you can increase the strength of your project. This can be great for weight-bearing items such as shelves and chairs.
You’ll need to use strong woodworking joints to build a set of free-standing shelves. There are several options to choose from.
Wood joints are often employed to conceal the methods that woodworkers use to hold each part together. Indeed, a well-made joint can often be hard to see, with the workpiece flowing as one piece of wood.
Though many joints are intended to conceal, some, such as the famous dovetail joint, are used as a decorative element that shows off the woodworker’s skill.
Beginner Friendly Joints and How to Make Them By Hand
Some joints are easier to make than others. Let’s take a look over some of the most common.
A basic butt joint is the most simple kind of joint you’ll ever use. In fact, there’s a good chance you’ve already made one before. As the name suggests, a butt joint simply requires you to glue two pieces of wood together, typically end grain to either edge or face grain.
There are no interlocking elements cut into the wood, and as a result, it’s one of the weakest joints unless it’s reinforced in some way. Despite this, there are plenty of uses for butt joints, such as in the construction of small boxes, light frames, widening boards, and even stud wall frames.
A butt joint can be either square cut or mitered. A mitered butt joint is more attractive as it hides the end grain. When you join the end grain to the face grain, it’s typically known as a box joint. Meanwhile, joining end grain to edge grain is known as a frame joint. If you want to fix two pieces of wood together to make a board, you can use a butt joint that fixes edge grain to edge grain.
How To Make a Butt Joint
A square butt joint is easy to make and only requires you to cut your wood to length using a bench hook and a tenon saw. The mitered butt joint is a little more difficult, but with a miter box and a little care and attention, it shouldn’t trouble you. You can use either a square or miter whether you want to make a frame or box joint.
Once the pieces of wood are cut to size, you can use a bench plane set to a fine cut to finish the job. Then, simply apply glue to both edges and clamp them together, ensuring they’re aligned properly.
Reinforcing Butt Joints
The easiest way to reinforce a butt joint is to use nails after the glue has set. On a square box joint, drive the nails in at angles for the strongest fit. Alternatively, glue wooden corner blocks on the inside of the joints.
For a miter joint, drive the nails straight through the joint and use a punch to hide the head below the surface. Just be sure to use nails that are long enough to pass through both pieces of wood.
One final method can be used on a mitered frame or box joint to create a decorative yet strong joint. Cut a series of angled slots into the glued joint and glue small strips of veneer, known as splines, into the saw cuts. Once the glue has set, trim the veneer spline flush.
A lap joint, also known as a rabbet joint, is another easy wood joint to make that requires minimal cutting. It’s not a lot stronger than a butt joint, but is generally considered more attractive since less of the end grain is visible. Like butt joints, mitered lap joints leave a cleaner finish, but are more difficult to cut.
They’re also called rabbet joints since the uncut, square end of one piece of wood sits in a rabbet cut into the face of the other piece. With a mitered lap joint, you’re required to cut both pieces of wood, cutting a miter onto each. This is pretty difficult for a beginner, so we won’t discuss it in this guide.
Rabbet joints are typically used in the construction of simple boxes and cabinets. In general, the rabbet is cut into the longer member, with the uncut piece forming the shorter side member.
How To Make a Lap Joint
A basic, square lap joint is easy enough to make but it does require careful marking and cutting. Before you start, make sure both parts of the joint have been cut and planed perfectly square. Using a marking gauge set to the same thickness as your side member, score a shoulder line on the face of the rabbet member.
Next, set your marking gauge to about a quarter of the thickness of the rabbet member. Now score a line across the end grain and up on the two edges, meeting the shoulder line you previously marked. When all the lines meet, clamp the rabbet member in a vice ready for cutting.
Using a tenon saw, carefully cut down the line scored on the end grain until you meet the shoulder line. Lay the rabbet member face down on a bench hook and cut down the shoulder line to remove the waste. If needs be, use a shoulder plane to clean up the rabbet.
Finally, fit the two pieces of wood together then glue and clamp the joint. You can reinforce a lap joint by carefully driving panel pins through the rabbet member into the side member.
Half Lap Joints
A half lap joint is a popular choice for framing projects that use pieces of wood of equal thickness. They’re easy enough to cut with hand tools and come in a number of varieties, such as corner, cross, and tee half-lap joints.
In the most basic form, a half-lap joint is cut square but mitered and even dovetail variants can be employed for decorative purposes and to improve the strength of the joint.
How To Make a Corner Half Lap Joint
Lay your two pieces of wood side by side and mark a shoulder line across both faces. The shoulder should be the same width as the wood you’re joining. Next, set a marking gauge to half the thickness of wood and scribe a line across the end grain and around the edges to meet your shoulder line. The markings on both of your pieces of wood should be identical.
Clamp your workpiece in a vice, then using a tenon saw, cut down from the end grain to your shoulder mark. Lay the piece on a bench hook, then saw down the shoulder line to remove the waste. Repeat this for the second piece. Then glue and clamp the two pieces together and if needed, reinforce with screws or dowels.
You can also make a mitered half lap joint by marking a miter on the face rather than a square shoulder. While this looks good, it does reduce the total surface area for gluing, making the joint weaker.
How To Make a Cross Half Lap Joint
Cross half-lap joints follow the same principles as a corner joint, but instead of having easy access to the edges, you’ll need to make the cuts in the middle section of the wood. Again, half of the thickness is removed from each part and they’re then slotted together to form a cross.
To make the joint, lay both parts together side by side and mark the two shoulder lines, the exact width of the wood. Next, set your marking gauge to exactly half the thickness of your wood, and score the depth line on each edge. Use a tenon saw to cut down the shoulders to your line. Then, make two or three additional saw cuts between the shoulders.
Clamp your workpiece in a vice, then use a sharp chisel to cut a recess down to your mark. When both pieces are done, fit them together, and if everything looks good, glue and clamp them. Traditionally, the upright section should appear to run uninterrupted.
How To Make Tee Joints
These follow the same principles as both the corner and cross joints. One member will have the recess cut out using a chisel as above, while the other will be cut at the end of the piece, slotting into the recess tightly.
This joint can be strengthened considerably by cutting a dovetail lap joint rather than a square one. The easiest way is to make a dovetail template that butts up to the end of your lapped piece. Mark and cut the dovetail lap, removing exactly half the waste as before.
Then, use the cut piece to mark out the recess in your cross-section. This way, you’ll know it’s exactly the right fit. Finally, saw the shoulders and chisel out the waste as above.
A scarf joint is used to join wood end to end in order to increase the length. Its most common application is in baseboards, though it can be applied elsewhere, such as timber rafters. The basic version is pretty simple, though there are many variants that increase the strength but are more complicated to cut.
A basic scarf joint basically requires you to cut a long, shallow taper on each end, ensuring each side matches. This provides plenty of surface area for gluing, increasing the strength. With baseboards, that’s pretty much all you need to do since the joint won’t bear any weight. In fact, some DIYers just use a 45-degree miter joint, though a longer, shallower angle is preferable.
Edge-to-Edge Joints For Making Boards
Some woodworking projects require you to join several narrow planks together, edge-to-edge, in order to make a larger panel. Cabinet doors and table tops are just some of the applications.
With strong, modern wood glues, it’s easier than ever to make a board and even a simple edge-to-edge butt joint will do the trick in most cases. However, there are a few things to know that will improve your panels, preventing warping and other issues down the line.
You’ll need wood that is perfectly flat and straight, all the exact same thickness, if you plan to make wide boards. Also, be sure to seek out well-matured, dry wood that is less prone to shrinking and expanding. Quarter-sawn planks are the best choice with the grain running as straight as possible.
When you’re putting them together, check the end grain and look at the direction growth rings. For best results, alternate each board. For example, the rings should arch upwards on the first board, then downwards on the next, then up again, and so on.
This ensures that the individual pieces move in different directions as they shrink and expand, essentially canceling each other out. This prevents cupping and warping and keeps the wide board stable.
Types of Edge-to-Edge Joints
If you’re only using hand tools, edge-to-edge butt joints are by far the easiest jointing method and in most cases, they’re more than adequate. However, with access to a router, you can make a tongue and groove joint. With a tongue and groove joint, it’s easier to put your board together and it provides a stronger finish.
Alternatively, a quick and easy way to reinforce an edge-to-edge butt joint is to create a dowel joint. Dowel holes are drilled into each edge, and wooden dowels are hammered into them. This makes assembly much easier without the extra work of a tongue and groove joint.
We’ll look at how to glue and clamp edge-to-edge joints in the next chapter.
Intermediate Joints and How to Make Them By Hand
Once you’ve mastered the beginner-friendly woodworking joints, you can up your game and try some of these slightly more complicated but typically stronger wood joints.
A dado joint and a housing joint are the same, and the two words are used interchangeably. Basically, a housing is a groove that is cut across the grain on a piece of wood and a dado joint is created when this groove houses a board of the same thickness.
The most common application is in fixed shelf making, where the shelf sits in a housing on either end. There are a number of variations, including square and either single or double-sided dovetails. Additionally, a dado joint may be cut through the entire length, or for a more attractive finish, it can be stopped short of the front edge of the workpiece.
With a router, these joints are easy to make, but with patience, they can also be made by hand.
How To Make a Dado Joint
To make a simple square through housing joint, you can use your shelf, or piece of wood that will sit in the groove, as a template when marking out. Square your marking lines onto the two edges, then use a marking gauge set to a depth of around 1/4″ to mark the depth.
Next, cut the two shoulders with a tenon saw, down to your depth mark. If you’re working on a wide board, you might find it easier to clamp a guiding batten along the line. With the shoulders cut, you can use a chisel to chop out the waste, going bit by bit, from each edge to the center. This way, you won’t split the wood.
When it’s done, you can tidy the groove up with a router plane if you have one, ensuring it’s completely level.
Making a Stopped Dado Joint
If you want to make a stopped joint, the process is much the same. However, instead of cutting a groove all the way across, it will stop short about half an inch or so. On your shelf, you’ll need to cut out a small notch. Set a marking gauge to the planned depth of your groove, and mark the edge of the shelf from the end grain. Mark also half an inch on the face from the edge.
Once you’ve cut the notch out with a tenon saw, use the notched shelf to mark the housing exactly. From the stopped end, carefully chisel out the waste and square the edges. Then, saw out the shoulders as before and chisel out the rest of the waste. The joint should fit together snugly.
Mortise and Tenon Joints
The venerable mortise and tenon joint is among the most versatile of all woodworking joints. It’s been around for many centuries and remains a very common joint for constructing doors, windows, cabinets, tables, and chairs.
In its most basic form, a tenon, a wooden tongue, is cut onto the end of one of the pieces of wood, typically the cross-section, known as the rail. This fits into a mortise, a slot that has been cut into the other piece of wood, typically the upright section, known as the stile.
There are a great many variations of the mortise and tenon joint, including single, double, wedged, haunched, through and stopped, to name just a few. For this beginners guide, however, we’ll focus on the basics. In future projects, we’ll delve into haunched mortise and tenon joints for corners of frames.
How To Make a Basic Mortise and Tenon Joint
A mortise and tenon looks tricky at first glance, but once you’ve made a few, they’re easy enough. If you follow a few rules of thumb, you’ll master the basics in no time:
- Use the rule of thirds: For two members of equal thickness, the best practice is to split your workpieces into thirds. The tenon should be one third the thickness of the rail, with the other two-thirds on either side removed. However, the mortise size is generally dictated by the size of your mortise chisel. Therefore, it doesn’t have to be exact but choose the chisel that is closest to a third of the width.
- Leave your rail long: The section on which the mortise will be cut should be left slightly long. This allows the tenon to stand proud of the edge, ready to be planed down flush, creating a smooth finish and removing the danger of stopping short.
- Cut the mortise first: It’s easier to first cut out the mortise and then make a tenon that fits it than vice versa.
Marking a Mortise and Tenon Joint
Use the rail as a guide to mark the position of the mortise on the stile. Square all the lines round the entire piece of wood. Then, grab your mortise gauge and set it to the width of the mortise chisel you’ll be using, remember to keep as close to a third of the total thickness as possible. Score the lines in the center of the markings to mark where the mortise will be chopped.
Now mark the tenon on the rail. Use the same mortise gauge and scribe two lines on the end grain and on each edge. Mark a shoulder line just a little wider than the thickness of the stile, to ensure the tenon will sit a little proud when it’s fitted. Square this all the way around and join all the marking lines together.
Chopping the Mortise
The quickest and easiest way to chop out your mortises is to drill holes to remove the bulk of the waste. Then, use your mortise chisel to form a square or rectangular hole. Be careful when drilling though, If you don’t keep it straight you can ruin the joint. For best results, a pillar drill should be used.
To chop the mortise without pre-drilling, start in the middle and drive your mortise chisel about 1/8″ into the wood. Then, work backward, making similar cuts until you’re about 1/16″ from the edges of the mortise. Lever the chisel to scoop out the waste until you’re about halfway down.
Next, trim the edges square and repeat the process on the other side until you’ve cleared the entire mortise.
Cutting the Tenon
Before you cut the tenon, bring your marked rail to the mortise to check that everything lines up okay.
If it’s all good, clamp the rail in a vice with the end grain facing away from you at an angle. Saw down to the shoulder line on each scribed line. Then, remove the rail from the vice, turn it around, and clamp it back up again with the end grain facing you. Saw down to the shoulder line once again on the other side of the tenon.
Then, lay the rail on a bench hook and saw the shoulders, removing the waste from both sides. You should now be left with a tongue of wood. Fit the joint together, paring away the sides of the tenon if necessary. It should be a fairly tight fit.
A bridle joint looks similar to a mortise and tenon, but it’s not quite as strong. They’re normally used for frames and are pretty quick and easy to make since the majority of the waste is cut off with a saw.
The bridle joint comes in two variants; a corner bridle joint and a T bridle joint. The latter generally serves as a support for a frame, such as joining table legs to the under-frame.
Neither is a very strong woodworking joint and they shouldn’t be used for heavy-duty or load-bearing applications.
How To Make a Corner Bridle Joint
A corner bridle joint is made in a similar way to a mortise and tenon. Divide the thickness of your wood into thirds and mark and cut the tenon in the same way, remembering to keep it slightly long.
For the mortise member, mark it identically to the tenon. This time, you’ll be removing the middle section rather than the two outer cheeks. To do this, saw down the two lines with a tenon saw, then use a coping saw to cut out the middle section.
Square the shoulder using a chisel. The tenon should slot snugly into the gap. To reinforce the joint, you can drive two dowels or screws through the side after the glue has set.
How To Make a Tee Bridle Joint
The mortise member is made in the same way as above, while the tenon is formed in the middle of the other piece. Mark your wood, using the tenon member as a template, and square the lines all around. Use a mortise gauge to divide the tenon member into thirds and score lines on both edges.
Lay the wood on a bench hook and cut the two shoulders on each face. Then, make two or three similar cuts between the shoulders. Use a chisel to remove the waste, working from each edge into the center to avoid splitting the wood.
What About Dovetail Joints?
The iconic dovetail is one of the most well-known woodworking joints. A favorite among furniture makers, it’s mostly used to make strong drawers that won’t fall apart when they’re opened and closed. You can also use a dovetail joint for making decorative boxes.
However, dovetails are among the most difficult woodworking joints out there. Indeed, cutting a dovetail joint by hand isn’t exactly beginner-friendly. With that in mind, we won’t go into how it’s done in this chapter, but it is something we will come back to in the future.
Nowadays, most beginners can make great dovetail joints using a power router and jig. Once we’ve completed a few more beginner-friendly projects, we’ll take a look at how it’s done.
Putting It All Together
Joining wood is all well and good, but your project won’t be finished until they’re all clamped and glued up. So, stay tuned for chapter 17, where we’ll look at all the essential tips and tricks to keep your work in once piece.