The Timeless Dovetail Joint
Dovetail joints have been used for thousands of years, even the pharaohs of Egypt had dovetail joints in their sarcophaguses. This article will tell you step by step, how to make dovetail joints.
Before you start
Now would be a good time to get your tools together, you will struggle without them, trust me. You will need:
Mallet, bevelled chisels, a marking knife, hand saw, hard pencil, try square, ruler, smoothing plane and coping saw.
Get your plans ready, make sure you know how big you want your project to be.
Choose your timber. Both hard and softwoods can be used, softwood is ideal for smaller projects, but it’s your choice.
Time to get to work
Once you have your ideal boards, cut them to your desired length and get the planer to work. Plane your edges until you have a smooth finish on all sides, ensuring your corners are as close to 90° as you can manage.
Lay out your boards in the desired shape. With a pencil, mark all the internal corners, these will be your shoulder lines.
Once your shoulder lines are marked, set your cutting gauge to the exact thickness of the joining boards. It’s easier to use boards which all have uniform thickness. Though not impossible to use different widths, it’s just a matter of adjusting your thicknesses accordingly.
Now you have your timber gauged and ready, it’s time to mark the half pins, half pins sit on the outside of the joints are usually between 6mm and 9mm, however it is not uncommon to increase the size for larger projects. Use the marking gauge to mark the pins at your required size.
Sketch the male end of dovetails using a pencil, a 20mm tail is ideal for small projects like drawers and small boxes. Wider dove tails are good for strength, and if you are doing a large project, use larger dovetails.
The slope from the end of your dovetails is what creates the strength in the joint, for a softwood a 1:6 angle is the standard. Harsher slopes such as 1:7 and 1:8 are more typically used for hardwoods.
Once you are happy with your dovetails, gently use the Marking knife on shoulder lines, this will allow a fine edge for your chisel to pare out the required channels for the dovetails later.
Before you start going crazy with the hand saw, mark your waste! This will prevent frustrating backtracking and remarking.
Get The Saw Out
- To start the cutting, use a hand saw and cut your marked dovetail edges down to your shoulder line. It is highly recommended to use a vice and square for the cutting phase, this will keep everything straight, and prevent miss cuts.
- Using the coping saw, remove the waste. Don’t make your job harder than it needs to be, allow a few mm at toward the shoulder line, for the chisel to touch up later, will save you some time and effort.
- Once you have removed the waste chunks, clamp your board tight, and get to work with the chisel. Pare through the board until you are just over half way. Flip the board and repeat the process on the other side, you should end up with a fine looking set of dovetails on the end of your board.
- Now your dovetails are cut, place the male and female lengths together and secure with a vice and clamps. When your boards are flush, use a sharp pencil and trace the dovetail outline on the female timber. Don’t forget to mark your waste, you’ve made it this far with no errors I hope. Keep up the good work.
- Once you are prepared and ready, repeat the above cutting process on the female board.
Nearly there! You have your male and female boards cut and ready, now it’s time to make a few trims so everything fits together as they should.
Take a chisel to the inside face of the tails, this will make the two slide together easier, and won’t change the integrity of the joint.
Time to fit your dovetail joint! Don’t use any glue yet, no need to get ahead of yourself. Use the mallet and a piece of scrap wood. Gently tap the joint together, they should join firm, but not over tight. If the joint feels too tight, separate the boards and trim with the chisel again for a snug fit.
Once your joints feel right, separate them and apply the glue to parts of the wood where the dovetails meet, once the glue sets off, the joint will be inseparable. Use a clamp if you want, to hold the pieces together for extra adhesion, though it’s not necessary.
Sit Back And Wait
Time to let the glue set. This is a perfect time to admire your work and get yourself a cup of coffee.
Time has passed and the glue has set, trim of any excess wood that has overlaid. Don’t fret if you have a lot to trim, this can be a technical process to master.
If required, use a sanding pad to smooth off the joint for that final touch.
That’s all there is to it! You now have a strong, reliable joint for your project, no nails required. Now would be a great time to get to work with staining, or leave it natural for the original wood aesthetic.
Only The Tip Of The Iceberg
The dovetail joint comes in many different styles. In this article, we only covered the basic. Through dovetail joints are great at what they do, but what if you want to hide the joins? Other types of dovetail joints are:
- Half-blind dovetail – Which hides the end grain from site, ideal for drawer fronts.
- Secret mitred dovetail – Has the same strength as the through dovetail, but completely hides the join from sight, no matter what angle you see it from.
- Sliding dovetail – This is used for joining two boards together at a right angle, where the join appears in the centre of the board. Ideal for joining shelves and partitions.