A custom putter-hammer is exactly what my nephew, a woodworker and a golfer, needs in his kit. Either for hard to reach fasteners or R&R at the links, this putter-hammer nails both!

Supplies

Parts were simple, fate provided me with a head of an 8 oz. claw-hammer which broke off the handle. I went to a local used sporting goods shop and found a nice putter for a few dollars. Lastly, a little J-B Weld to epoxy the parts together.

The tools I found helpful included

Bench vise with 3 axis swivel (quite helpful !!)
Some scraps of card stock / heavy paper
Wood rasp
Speed square
Mallet
Awl
Drill and a collection of drill bits ( I used 5/16" and 3/16" and 1/16")
6" Spirit level
Masking tape
Dremel rotary tool with following tools
cut-off wheels
flap wheel grinder
carbon steel brushes, both side and forward style
felt polishing wheels, large and small diameter
polishing compound

Step 1: Parts Preparation

Cutting the existing putter head from my upcycled purchase was easy. Just clamped the head in the vise and used a rotary cutting wheel. The cut end of the shaft gets buried in epoxy later, so a reasonably squared off end is fine with no other prep.

The makerspace I am at has a nice vise. However, the jaws are metal and could mar the hammer head. A little card stock works well to buffer between the vise and hammer head.

The handle remains in the head could be used as a seat for the shaft. Regulation putters are typically 20 to 30 degrees off straight up and down. The one I cutoff was 23 degrees, which I decided to copy. Set the head to that angle in the vise to get started.

Because the broken wooden handle was a mess, I wasn't sure if there was a metal fixing wedge inside. Clamping it up, I gingerly cleaned up the remaining shaft with a wood rasp, testing for metal. Luckily there was nothing.

Drilling straight down into a tilted head is a bit tricky, particularly into the handle's hardwood. With a mallet and an awl, I set a hole for drilling, then used successively larger drill bits until just past the shaft diameter (5/16"). The speed square helped guide the drilling and alignment, which you can see in some of the photos.

The haft seated into the wood nicely and had a little play for adjustment.

Step 2: Epoxying the Headspace

With the assembly ready, I masked around the head to catch overspill. The epoxy has a 3+ hours set time which is why standing the shaft up in the tilted head is useful. Gravity plus the wooden seat can hold the shaft straight up. Consulting a spirit level ensured alignment. I did have to cut a few shims of wood from the broken handle to tamp around the shaft to wedge it up just right.

Although the headspace opening was not level, J-B Weld is viscous enough that it will not run out the lower end. Due to that viscosity, I used a thin nail to poke up and down around the fill, catching a few voids. Added enough to fill the head and let it cure overnight.

Step 3: Cleanup

Cleanup is pretty easy with a rotary tool. The multi-axis swivel vise made it easy to reposition for cleaning and polishing the nooks and crannies.

The mask left only a little spillage on the shaft and along the head. Carbon steel brushes made quick work of that.

I noticed the hammer face was a bit rough, so I used a flap wheel to grind it smooth. Although I took a few grams of weight off, technically 8 oz. is too heavy for some golfing regulations. Everything that came off was for the better.

The steel polishes up nicely using felt wheels and polishing compound.

I was happy with the results for a fun gift!