How to make dovetail joints by hand?

The dovetail joint gives corners a much stronger tensile strength using a series of trapezoidal shaped tails and pins that fit together much like a jigsaw puzzle. The tensile strength provided by the dovetail joint improves the quality and workmanship of the piece of furniture or structure immensely. The angle of the pins and tails are much more effective at providing strength than a series of nails or screws. Add wood glue and you have a joint that is extremely strong and reliable.

To fully explain how to cut a dovetail joint, we need to first describe the various parts of the joint. The corners of any type of structure, whether it’s furniture or a building, have to be strong enough to help support the structure. A few nails or screws will hold a corner for a while, but they lack tensile strength. The angle of slope used for the tails and pins depends on the type of wood used. Usually the slope of 1:6 uses for softwoods and a 1:8 slope for hardwoods. Also you can use a slope of 1:7 if 1:6 or 1:8 aren’t appropriate for whatever reason.

If you are a beginner at making dovetails, then buying a dovetail jig will help you in this respect. Something like magnetic dovetail jig will be an incredible help for cutting out this joint. Other than that, a dovetail saw, marking gauge, a marking blade, a square, pencil, and chisels of various sizes will be required for perfect dovetails.

This is one of the most important steps of this whole process because cutting dovetails is all about having perfect measurements. If you have measured wrong then you are most probably going to have gaps in the joint. Take your marking gauge and measure the thickness of your pinboard with it. Now mark the tail board using that measurement that you took of the pin board’s thickness. Just ensure that you don’t mark the face side too deep, but dig deep in the backside of the board. Now do the same process with the tail board by taking its measurement and marking the pin board.

Now it is time to move on to measure out the tails and mark them properly. Use a ruler or dividers to measure out tails. To do that, you either use a dovetail template or use a ruler, marking 5mm on both sides. Then take your dividers, and make marks from one 5mm line of the board on the end grain side to the other. Then from the other side of the end grain to the one you started from. Now make lines where the divider holes or marks are and you will have an equal amount of spacing for the tails. Using a dovetail guide or a dovetail gauge, angular bevel gauge, draw out the tails on the face and backside of the board.

On the backside of the tail board, make a rabbet using a rabbeting planer. This will help in supporting the tail board on the pin board and allow us to make marks for the pins on it. The lip on the rabbet will help us hold the board with one hand without movement so the marks for the pins are more accurate.

Using a dovetail saw and a dovetail jig, start cutting the tails vertically. Do this one side at a time, meaning you do one side for the whole board then flip it and another side for the whole board. Now cut out the half tails or corners with the dovetail saw leaving at least 1-2mm space between the shoulder mark. You don’t want to go all the way over the marks to always make sure there is enough space for compensation, you can use a chisel to clean that up later. For the middle pieces use a fret saw to cut the pieces in between. Use a chisel to clean out the curve you cut with the fretsaw when you are done.

Once the cleanup process is finished, make sure to use a chisel and a knife to clean any fuzz in the corners. Now place the tail board on the pin board and mark the tails using the tails as a guide with a marking blade. Use your pencil to draw out the lines on the mark and the waste as well.

Use the same method as before, using the dovetail guide or jig, start cutting the pins using a dovetail saw. Using the fret saw as before, cut the waste in between the pins, and afterward, using a chisel clean up between them.

Now that both the tail and pin boards are cut, take a chisel and clean up any excess using the shoulder marks and the lines. Once that is done you have a dovetail joint that is ready to be set together. Using your hands slide the tails into the pins, and gently tap the boards with a mallet. Also, don’t forget to make a slight chamfer on the back of the tails where the rabbet is. This will help the tails and pins slide in with much more ease.

If both the pieces aren’t fitting together if it is too tight, take a file, file the tails down gently, and don’t file the pins since they will be thin. Here is a pretty comprehensive video tutorial on how you can make the perfect dovetails by hand.