The dovetail joint is a wood joinery type that creates a strong and long-lasting connection between two pieces of wood. It is a joint of two wood pieces with squared edges, one fitting into the other like a puzzle. When the puzzle cut is done, it looks like a dovetail connecting woods with a powerful pinch.
There are many methods to cut dovetail joints. However, you can classify them into three main groups: by hand sawing, by a power saw with a dado blade set, which you call table mounted joinery system, and by power sawing without dado blades which mean by handheld.
You can also use a wood router to cut dovetail joints.
Dovetail Cuts And The Tools
- A dovetail saw
- A chisel
- Mallet
- Chalk line
- Glue
- The square section of wood
- Sandpaper
Dovetail Joint: Process
The first step is to determine how wide the dovetail should be. You can estimate it by measuring the thickness of the board. It is wise to err on the side of wide pieces. It will allow you to ease clean-up, identify and repair the waste parts early, and ensure a high probability of success.
After the wood’s width is determined, mark out the pieces on their edges, and measure their thicknesses. Then try with your hand saw to cut. The hand saw is a kitchen cutting knife with a handle at the end. It is vital to keep both surfaces square and flat throughout the cut.
One noticeable thing here is to keep in mind that only one side of the dovetail will be sawed, and it will always be the more visible one.
Before the saw has even begun cutting, smooth down both edges of the board. A smoother, which I’ll refer to as a plane, can be used to get a nice surface on either side of the board. It is possible to simply use sandpaper on a flat surface, but that is more time-consuming and not quite as effective.
Depending on the size of the board, you can use a bandsaw or jigsaw to make the dovetail slot. If you use a bandsaw, place the board as flat as possible and have its edge clamped down. It will make the cut more precise and easier to clean up. On the other hand, if you shape it with a jigsaw, keep the blade as a fine-tooth type, and you have to cut the slot a little wide. It will help with proper fitting.
It is now time to use a dovetail saw to cut the flattened edges of the dovetail. It is a precise tool, with a rigid blade and an adjustable set of teeth, and is both slower and more difficult to use than a hand saw. But this tool will be instrumental in the coming steps. The first cut can also be done with a pair of hand saws, but at a later point, the dovetail saw should always be useful.
The rough fit with the dovetail saw is then cleaned up in a couple of ways. Small pieces are removed with a chisel and mallet, which is done by clamping the wood in a vice, placing a piece of wood on top of the piece to be cut, and striking that. Marks should be made before each strike to allow for accurate shaping. It will also prevent rounding the edges of the dovetail.
Using the bevels on the dovetail saw’s teeth, carefully round the areas that were cut with a mallet. This step is crucial because it will preserve the edges of the joint when cleanup is to come. Since this is such a thin piece of wood, rounding makes the cut into the wood less likely to tear it out of place.
Applying glue is a technique that can help to strengthen the joint and make cleanup much easier. It should be done while the saw is still cutting after all the edges that were cut are rounded. If the glue is applied first and then the saw is removed, the wood will break out of its new shape.
Once the glue is applied, continue sawing, trying to cut straight down. I usually use my foot to press the back to more easily guide the saw’s teeth, but you can also use a piece of chalk. This process is called feather cutting, and the tool and its motion should be used thoughtlessly. Sometimes this step gets a little more difficult when the saw has to cut into the back of the joint, and requires more sweeping motions between cuts.
After this has been done, the joint is ready for a cleanup. Handsaws work well for this, although I always prefer a dovetail saw. Cutting into the other end of the joint as well can make cleanup easier. These types of saws are not as precise as the dovetail saw and should always be used by an experienced person.
All the cuts should be taken out, the surfaces of the pieces smoothed, and the joint checked to see if it is square. If the cuts are far enough off, the joint could be made again.
It is also a good idea to glue the table saw rip fence to the surface of the table or vice so that it is in exactly the same place on each cut. This prevents the blade from moving to the side, breaking off the bottom, or tearing out the edge of the joint.
Once the joint has been cleaned up, it can be sanded. I’ve come across a couple of methods for this. One involves taking a square section of wood, placing it between the joint and a piece of hardboard, and hitting the joint with a sander. More often though, I use a plain old piece of sandpaper, cut to the proper size, to sand the edges. This can also be done with a block of wood, especially if the joint is particularly long.
This completes the dovetail joint, a very useful joint that is invaluable in many things, but even more useful if used in other types of joints like box joints.
Conclusion
The dovetail joint is an intricate mouth-to-mouth joinery that is used in a large variety of situations. It can be used in woodworking as well as other disciplines, such as engineering. As with many joinery methods, the dovetail joint starts with a cut into two pieces of wood.