Re-Handling a HAMMER

by Albin Drzewianowski

Last issue we talked about the basics of selecting a blacksmithing hammer. Now lets talk about putting a new handle onto a hammerhead. This is a very useful skill for a beginning blacksmith for a number of reasons. First and foremost is economy. There are a lot of hammer heads available for at most a dollar or two and they only thing they need is a new handle and maybe a little clean up. Secondly, some new hammers may come with a totally unsuitable handle or it may come from the factory loose and may need to be tightened or replaced.

Before installing a new handle, lets talk about loose handles. First of all, we are talking about hammers here. You want a good tight connection between hammer head and handle. However, when it comes to "handled tools" or "struck tools" such as flatters, set hammers (which really aren't hammers), hot and cold cuts, etc: they do not need to be tight, in fact, it is better if they are a little loose (not falling off loose), less vibration is passed to the hand holding the tool. In fact with curved hot cuts/chisels, it is handy to be able to slip the hot cut off the handle and reverse it, so that the curve goes the other way.

Getting back to hammers: due to the nature of wood, it has a tendency to swell up and shrink down. Thus over time just about every hammer handle will become loose. A loose hammer head is a danger to yourself and anyone who is standing in the general area, as you are forging. I have seen those smiths who working with a loose hammer head, slam the hammer down, butt first on the anvil to re-seat the hammer head for the next few blows. The operative word here is FEW, that solution is a very temporary one. Also, there is an old wife's tale, that to fix a loose hammer head, just put it in a bucket of water. Again, this is a temporary solution. It actually make matters worse. When you soak a hammer in a bucket of water, the wood swells up and since it can only expand so much inside the eye of the hammer, the wood fibers end up getting crushed. Once the wood dries out, which it will (unless you constantly store the hammer in a bucket of water), the hammer is looser than when you started. The best way to fix a loose hammer, is to drive in another steel wedge. If there is not enough room for another wedge, than it is time for a new handle. Some people say that soaking the hammer in anti-freeze will tighten up the head without causing the wood fibers to swell and be crushed. I have not tried this, but have heard it mentioned often.

Removing an old handle - If the handle is not so loose that it comes out easily, I usually take a drill and drill down into the wood inside the eye. This then allows me to use an appropriate size punch to drive out the old handle.

Putting on a new handle - Start with a good hammer handle made of straight grained hickory or ash. Looking at the butt end of the handle, the grain should be running up and down the long dimension, not across, Fig. 1. Using a wood rasp, start rasping down the part of the handle that will go into the hammer head. It is very important that handle is kept straight and perpendicular to the hammer head. Work slowly and from all 4 sides to keep the handle centered to the eye of the hammer. Once you have shaved it down such that the hammer is a very snug fit, move on to the next step.

Cut a slot in the end of the handle, centered and lined up with the long axis of the handle, Fig. 2. This slot should be as deep as the hammer eye. When I am doing a hammer handle, I usually prepare the handle so that about 1/8" of wood extends beyond the top of the hammer, and I cut the extra wood off after driving in the wooden wedge. After cutting the slot, install the hammer on the handle. To seat the hammer head, I strike the butt of the handle with a wooden mallet, this drives the head down tight. Next take a hard wood wedge that is as wide as the slot and drive that down. The length of the wedge should be at least 3/4s the depth of the hammer eye. Remember, that on a well made hammer, the eye socket will be hour-glass shaped - wider at the top and bottom and narrow in the middle. By driving the wedges, you are trying to spread the wood above the waist in the middle of the eye. Some people like to put a little wood glue on the wooden wedge before they drive it in. Others like to put some silicone epoxy in the hammer eye before they insert the wood handle. The wooden wedge should not be too thick. I have found that just a little less than 3 times the width of the saw kerf seems to work well. If the wedge is too thick, it will not dive in very far and have a tendency to work its way back out. At this point I will trim any excess wood sticking out above the hammer head, so that the end of the handle is flush with top of the hammer head.

The final step is to drive in one or two steel wedges. They should be driven in at about a 45 degree angle to the wooden wedge, Fig. 3. Try to leave room for a future wedge, if the hammer gets loose with age.

Here is a extra step I have heard about, but have not tried. Before you start rasping the hammer to fit the eye, dry the hammer handle in the oven at the oven's lowest heat setting for an hour or two. This will drive off as much moisture from the wood handle as possible. Then right away finish shaping the end of the handle and install the hammer head. The natural humidity (which we have lots of here in Maryland) will re-hydrate the wood and cause it to swell slightly and give a really tight fit.

Where to get hammer handles - They are usually available at hardware stores. I have found them at a better price at blacksmith tailgating areas or at steam show flea markets. Also, if you have a wood lathe or drawknifes, they are not that hard to make from scratch. I had an old hickory tree come down on my property and I stashed away a bunch of blanks that will be hammer handles in the future, after the wood dries.

Metal wedges - The traditional metal wedge is, well wedge shaped, (visualize a door stop). However, they now have conical shaped wedges that I often see in store bought hammers. These are somewhat tapered hollow cones of steel. These types of wedges are available from woodworking tool catalogs. For the traditional metal wedges, you can buy them at most hardware stores. But I just use 1/4" square mild steel: draw a long taper (after all we are blacksmiths), use a small fine chisel to put some barbs on the wedge, Fig. 4, and then cut it off with a hacksaw. In the past, I have used a small woodworking screw in place of a wedge, that seems to work nicely also to spread the wood and tighten the handle.

-- RebStaup - 25 Jan 2008