We dug an old sledgehammer head out of the yard, and while it was a fine thing to hold other things from blowing away with, eventually we needed a sledgehammer to knock the shit out of something or other. So I went and bought a hickory sledge/maul handle (at the recommendation of Clint Eastwood.) Then I had to figure out the correct way to install it.
As we all know, it can be hilarious but ultimately embarassing when a 10 pound sledgehammer is put together wrong. Nobody ever blames the head, and the handles seldom break. More often than not, it’s the joinery between the two that fails, and the crafty devil that performs the marriage who gets sued. I could have consulted my friend the cabinet maker, who spent many of his first months in the USAF Carpenters putting wooden handles on a variety of hand tools, but in the spirit of adventure, I consulted the internet.
Also in the spirit of adventure, I set my search criteria for “Axe Handle Replacement” rather than sledgehammer. This turned out to be a good (if inexplicable) move, as most of the instructions for sledge/maul handles are for the type that are held in with epoxy. Those are for squares, all the cool kids use the cross-wedge joint. It’s wicked steam-punk. It’s also how axe and pick handles are held onto their heads. And this brings me to an important distinction between the instructions found on two of the top listed websites.
The cross-wedge joint works because the tool has a tapered hole through it. The narrow end of the hole is the bottom of the tool head, and the wedges are used to widen the handle at the top of the tool head, forming a cork. Tool heads do not fall off their handles because the handles form a cork shaped profile within the head. This distinction is easy to miss with a tool head with no clear top or bottom on the outside (sledge, maul, ball-peen hammer, broad bladed axe) than it is with, say, a pick. The first website I visited gave me pretty much the instructions I expected. ‘Shave your store-bought handle down to fit through the head and drive the wedge in to hold it.’ (I was expecting these instructions because I’m a machinist and envisioned an interference fit between two parallel cylindrical surfaces.) Only, if you follow those instructions, and you’re lazy or uninformed, you just might shave down your new handle the wrong way; tapered to a cone shape, and not a cork shape with the fat part at the end. (And your audition for the next Mr. Bean movie will be underway.)
I would have embarrassed myself without the illuminating instructions available at hub pages dot com. The job would not have gotten done, and this post would not be. However, I thought there could be a more illustrated set of instructions, specific to replacing sledge/maul heads onto wooden handles. (I won’t point fingers at the more confusable online instructions, except to say that the domain name rhymes with the sound of a donkey braying.)
Remove the old handle from the head by drilling or soaking, but not fire
Find the top and the bottom and always keep the handle in the same orientation
Check dimensions if your slot is pre-cut into the handle
Check interference to determine where to shave the handle
Shave, shave, shave! use a rasp
Drive the wooden wedge in into the slot, don’t be gentle
Drive the metal wedge in perpendicular across the wooden wedge
Remove the old handle from the head. I had no trouble doing this, as the old handle had long since rotted away. Suggested methods are to drill a few 1/4″ or 3/8″ holes in the remaining wood (beware of steel wedges and nails that may have been used to tighten up the head) and drive the handle out the way it came in, or to soak the head in water (bloat) and allow it to dry (shrink) to loosen the head. As a side note, this is why you don’t leave your wooden handled tools out in the rain, it loosens them. Not recommended is setting the handle on fire or throwing the whole thing into a fire. This will change the temper of the tool head; not so crucial on a sledge, but bad for edged tools. I ran a wire brush through my hammer head, as it was pretty rusty.
Find the top and the bottom. The hole through my hammer head was hourglass shaped, meaning it had a tight spot right in the middle of the head, and the handle could be installed from either side. Since the hole was very asymmetric and the handle was going to be shaved down to match its peculiar profile, I had to assign a top and bottom, and even a left and right side. Conveniently, the handle came with two stickers on it, and I simply stuck one on the head, making sure to always check the fit with the two stickers on the same side, and the handle at the bottom of the sticker on the head.
Check dimensions. The pre-cut slot in the handle went further than the total height of the head. The head should completely cover this slot, to keep water and mud from getting into the head and weakening the handle. Better to remove any extra length from the end now rather than after you’ve shaped the whole length. I marked the handle where the middle of the head will sit, from there to the the top of the handle will have to be shaved down to fit through the narrowest point in the head, and from there to the bottom of the slot will have to match the taper of the lower part of the hole.
Check interference. The oval profile of your new handle will not match the profile of your old head. More material will need to be removed from some parts, and less from others. A good way to see where is to shine a light down the handle and look into the top of the head. Anywhere there’s contact, or shadow, is where the wood needs to come off. Also try the reverse, shining a light into the top and looking at the handle (once you’ve got the handle to go part-way in) DON’T TWIST the handle, keep the saw-cut slot in line with the axis of the head.
Shave, shave, shave! I used a flat rasp and a radiused rasp. By the time I was halfway done, I was wishing for a hand held belt sander or even a 4″ angle grinder with a sanding disc. I must have eyaballed the fit (as above) about thirty times while I was shaving down the handle. I didn’t take any pictures. Just remember that the top half has to be of a uniform size and profile to fit through the choke-point, and the lower half has to match whatever the inside of the hole is.
Eventually, I got the whole slot covered and had no gaps where the handle met the head. I drove the head onto the handle by holding the assembly vertical and tapping the handle end on the ground. It’s okay if the saw-cut slot collapses a wee bit, but not totally.
Drive the wooden wedge in. This wedge will apply pressure, and friction, on two sides of the hole. My wedge was a little wide so I snapped a bit off one side with pliers. The wedge shouldn’t touch the sides, as the metal wedge will split it and spread it in the next step.
I was surprised at how much of the wedge actually went in. I only trimmed about 1/4″ off the end. You can use wood glue on the sides of the wedge if it makes you feel better.
Drive the metal wedge in perpendicular across the wooden wedge. This will apply force to the remaining two sides of the head. I used a pin punch to sink the wedge slightly into the head, but not enough to admit any water or mud. I suppose you could treat the wooden end with some type of waterproofing at this point.