A Joiner’s Mallet in Walnut

March 7, 2016

I decided a good project for me would be making a mallet. I had a reasonably sized block of walnut lying around from my school days, and I needed one. I’d been using a plastic hammer with far too little heft. Generally speaking, the less mass a tool has, the faster you will end up moving it to generate the same momentum before contact. Momentum is mass ⋅ velocity, so this is a natural compensation. For humans, higher velocity tends to mean less control, so the weight of a tool can make a lot of a difference. You can see the plastic hammer and mallet parts side-by-side in the pictures below.

Of course a wooden mallet is also more traditional, and undeniably more aesthetic than their synthetic counterparts.

As all things should, this project started out with a little research and inspiration, these pieces are the ones that stood out for me. Paul Sellers’ and Steve Schuler’s are alike with the latter made from beautiful, beautiful spalted pecan wood (Schuler’s design is adapted from Sellers’). Steve Ramsey’s stands out with a beautiful, faceted, maple head.

In the end, I went with Sellers’ design for the heft, and rugged look.

Truing and squaring the block of walnut

The walnut had already been milled at the school, where I had access to mechanical jointers and thickness planers, but after a few months of lying around around in my apartment it had to be done again, this time by hand. Planing walnut is quite enjoyable. And the thickness planer had left “waterboard” marks on the wood, which made the plane chatter and vibrate on the first few shavings. A fun experience.

After planing, I cut the block in two in the direction of the grain, one part for the head, one for the handle. This part of the process coincided with me having access to a workshop, so I cut them on a bandsaw. Note the slight taper on the handle. The mallet isn’t glued up, so the mechanical strength of the tapered handle — wedging into a tapered mortise in the head — is all that’s keeping the mallet together!

Head and handle, bandsawn

The striking surfaces of the head are tapered more aggressively. I’m not sure how this affects usage, but it helps in making the edges and corners obtuse in the final result (later, the head’s top face will be rounded with a chisel and plane). Sharp angles are weak and prone to breakage. Sharp angles are also problematic with regard to finishing, as the surface tension in the finish will tend to drag it away from sharp corners.

Cutting the mortise

The bulk of the mortise is drilled out

The measurements for the mortise are copied from the handle using marking, gauge, ruler, square, and a marking knife. This way, the taper in the mortise is the same as that on the handle. To save time and effort, the bulk of the mortise is drilled out using an auger bit. The only bit I had was 8mm in diameter. A better fit would have probably saved me some effort.

The cut mortise

The faces of the mortise are then cut with a chisel (this is the part where a mallet would have been really useful). This was probably the hardest part of this project. Not only is chiseling a lot of work, if you get it wrong and make the mortise too loose, you have to start over.

When I was satisfied with the mortise, I planed a few shavings off of the handle, until it slid in with ease.

The last step was finishing. I went with two coats of boiled linseed oil. I actually haven’t been able to find raw linseed oil, as what the stores in Denmark sell as raw linseed oil seems to be boiled linseed oil. When you ask about it in the store, you get the same old story “I’ve been selling paint now for seven hundred years, and I’ve never heard of…”. I’m not sure why they think you’ll be impressed by them not knowing their field after working in it for centuries.

Linseed oil drying

The end result is a slightly rugged looking tool.

Finished mallet

Finished mallet

As you can see, the end-grain was not quite ready for finishing. Normally, I would have taken care to plane or sand (more likely both) that smooth before finishing, but this is a mallet, and I think it’s fitting that some plane-marks and similar are visible in the end result.

Actually, on a ‘real’ piece, sanding the end-grain is considered mandatory. The end grain soaks up much more of the finish than the rest of the wood, that’s why it’s so much darker. To avoid that, you sand the end-grain to a finer grit than the rest, to limit its ability to absorb the finish.

Finished mallet end-grain

That rounding on the sides of the head is not a photographic artifact. I made those with a plane. Many people assume a plane will always produce a flat surface (I guess it’s in the name), but it doesn’t necessarily. There is a reason the old-timers go-to tool for many odd tasks was the hand plane.

All in all I’m pretty happy with the result. It’s not perfect. It has some scuff marks, and the handle slid in a few millimeters more than I was aiming for. None of it really matters though.

Time will tell whether walnut is a decent choice for a mallet. I worry a little that the end-grain will split, leaving a mushy cavity in lieu of a striking surface. Walnut does, however, have strength properties similar to oak, so I think I will be fine.

When I’ve used it a couple weeks, and the wood has settled/shrunk/expanded, I’ll take the handle out and plane it down until it only protrudes a few millimeters from the top of the head. I’ll probably have to give it another coat of oil then, but that’s okay. I’m not satisfied with how I’ve broken the edges on the handle anyway, and it gives me an opportunity to fix that.