This is something that I’ve wanted to build for quite a while--an “Impossible” mallet. That is, a wooden mallet where due to the angles of the dovetails, the handle can’t be removed (along the the corrolary--it can’t be inserted either).
As one might guess, the mallet is formed by two solid pieces of wood--the head and the handle. Each one is a solid piece of wood, and it is assembled without glue. The key question that one should ask (at least I hope one would ask) is, “how was it made?”
I have to say that the design is not mine. I took the design from a number of articles from various wood-working magazines. Still, this project presented a host of challenges for me.
Primarily, it involved more (a *lot* more) hand tool work than I’m used to. Initially I tried making it (actually a single sample joint) completely by hand. In doing so, I found that my hand-tool skills were not nearly up to the task. The faces weren’t planar, the edges weren’t straight, and while it went together, it was very sloppy.
So I went on to Plan-B: power tools. Unfortunately, while they could do some of the work, a large amount was left to me to finish by hand.
The first step was to make the mortise and dovetails in the head. The mortise was pretty straight-forward. The bigger challenge were the rising dovetails. The “floor” of the dovetail is angled so that it is not parallel to any face. So at the top of the mallet head, the dovetails are fairly thin, but at the bottom of the mallet head, the dovetails are fairly thick. Is it just me, or does the bottom look like Darth Vader’s TIE Fighter?
I used a jig on the table saw to define the sides of the dovetails, and then used the jig on the router table to define the bottom of the dovetail. Unfortunately, the table saw blade could not get into the sharp corner of the dovetail, and the router could only clear out the very center due to the overhangs.
After that, it was almost all chisel work (along with really fine hand saw) to first widen the bottom of the dovetail to the full width, and then make the sharp corners. This last bit was very hard, as my chisels had relatively bulky sides, and I could only get into the corner by going straight in. When I made a second one, I bought a dovetail chisel with angled sides, and it was much easier (although still a pain for someone not used to hand work).
After many hours, I finally got the head done and started on the handle. The main job there was making the tenon and the mating dovetails. It would have been easier with a band saw, but I don’t have one, so I had to make due with the table saw. Once again, it could do about half of the work, and the rest was completed with hand saws and chisels.
At this point, I had just cut the handle down to the appropriate size rectangle, but I didn’t finish it further.
The key point on the dovetails is that the inside edge is “hollowed out” to allow the wood to flex more. Otherwise it would be truly impossible to assemble.
Then came the really scary part, trying to mate the two pieces. One unfortunate problem with this design is that you can’t really “test fit” the pieces together. You have to pretty much make the whole thing and then hope the fit isn’t too tight or too loose.
To fit them together, you use a clamp to squeeze the two dovetails together so that they will fit into the base of the deeper end of the dovetails. I found that at this point, I had to do a lot of fine-tuning of the “hollowing out”. Since the two dovetails were being squeezed against each other, if the hollowing out was not even, then one side would come in much further than the other. Also, it needed to be a fair curve so that the wood bent evenly and not sharply at one point.
When everything seemed OK, it was time to grit my teeth and pound the handle in. It was a real “white knuckle” time, as I didn’t know if it would work, or if all of my hours of prep work would be trashed.
The dovetails in the handle are cut extra long, and the ends beveled to help them fit into the dovetail slots. It turns out that bevels are even more crucial than I suspected. The dovetails in the handle have to bend in sort of a “S” shape--inward to go from the handle in towards the center of the head, but then outward again due to the angled floor of the dovetail slots. The bevels allow them to make that transition. On one of them, I didn’t make a big enough bevel, and it handle ended up pretending to be a wooden chisel that was digging up the base of the dovetail slots.
You also need to be careful that you don’t blow out the sharp corners of the head at the dovetail, which is while this is being squeezed by a vice. Finally, you have to worry that the dovetails of the handle don’t crack from the stress.
Fortunately, I got the handle inserted safely. In the next photo you can see the protruding ends of the mortise and dovetails.
After this (and after I started breathing again :-), the rest was easy. The protruding ends of the handle were trimmed and sanded flush. The faces of the mallet head were cut at a slight angle. And then the handle was rounded.
This rounding was almost all done by hand and was rather fun. It mostly involved a block plane, then a rasp and scraper. I did use a power sander to help with the transition, however.
The final step was to put some Watco oil on it, and then it was finished.
All in all, it was a satisfying project that let me practice my hand skills a bit more than I usually do. It undoubtedly took me longer than it would for someone use to hand tools, but for my first foray into major hand-tool land, and given that for the critical pieces (the dovetails), none of the surfaces are parallel to anything else, I don’t think it came out too bad.