With practice you can become very adept at chopping out mortises quickly and effectively.
When you are only doing a few mortises, this might be the occasion to slow down and listen to some music rather than whining machines, while chopping away wood with a chisel and mallet.
When you mortise by hand, you need a sturdy mallet to hit the mortising chisel. The head of the mallet should have sufficient mass to be able to drive the thick mortising chisel into the wood without hesitation. No light tapping here. Instead, repeated heavy blows are required.
This mallet was the first one I made, some 12 years ago, with scraps picked up at my first woodworking class. Over a decade later, and with hundreds of mortises to its credit, it is still in good condition.
The mallet’s mass is concentrated in its head; therefore it needs to be of a reasonably large size. My mallet’s head measures 2 ¼” x 3 ½” x 6”. The choice of woods is important to create a heavy hammer. Hardwoods such as oak, ash, beech, maple and elm are all good options. Since mine is made of scraps, it has a few different woods in it. The center layer of the head is red oak while the two outer layers are ash. The handle is made of beech.
The handle is tapered so that it wedges into the head. This prevents the head from being projected into space; in fact as you use the mallet, the handle gets wedged more strongly onto the handle. The opening in the head is wedged in the same shape as the handle. The wood in the head has its fibres oriented in the direction the mallet is going to hit the chisel. In other words, it is the end grain that will absorb the blow. Since wood is more resistant to compression in its length, it will be able to absorb the blows much better this way and fibres won’t get crushed as much.
Make the handle first. The longer the handle, the more leverage you get and the harder you will be able to strike, which is what counts in the end. However, the longer the handle, the less control over the head you will have and the heavier the mallet will feel in your hand (because of the lever effect). Find a reasonable balance. My handle is 14” long in total with 10” protruding from the bottom of the head. For me, this makes a mallet that is not too hard to handle and drives a chisel into wood without too much effort. The weight does most of the job for me.
The head is made of three layers, which makes it easy to build. Use three layers of ¾” wood to build a total thickness of 2 ¼”. Lay the handle onto the first layer and position the two pieces of the second layer on either side to create an opening for the handle to fit. Once these are glued, add a top layer to finish the sandwich. You can plane the handle a little if it is too snug. If the handle is too loose, make an appropriate size wedge to squeeze the handle tightly into the head’s mortise.
When cutting the head to its final shape, be sure to cut an angle at both ends. This is mainly for comfort. You can get a better sense of the angle that is right for you by standing in front of your work bench and keeping the almost finished mallet in your working hand. You will notice that if the end of the mallet’s head would be at a right angle, you would either have to put your wrist or shoulder in an awkward position. Adjust your position by focusing on comfort. With the mallet in position, mark where the head should be cut to strike the chisel more or less perpendicularly in that position.
You can leave the mallet unfinished, or apply an oil. Avoid wax, as it will make the handle slippery.
If you have some exotic wood scraps you can consider making a fancy hammer by adding some colour and contrast. Just bear in mind that some woods are strong and heavy but are very brittle. The woods listed earlier are shock resistant and have been used for tool construction for ages.
You can take this opportunity to be creative and decorate the head’s cheeks and the bottom end of the handle with some carving. It only takes a few curves to produce a personalized mallet that will be a joy to use for years to come.