Hammer time: the making. | "Traditional" Blacksmithing | Forum

Hello,  

I thought I would regale you all of my time thus far on the "hammer time" project.  

The first thing I did was use some machinists dye on the blank: I placed it on a flat surface, and ran a 90 degree square along both sides.  This served to mark the blank on two sides opposite from each other.  I then used a center punch to mark both ends of the slot I wanted to cut.  (It gave me a goal to keep the chisel inline.)

When I started with the chisel, I didn't have a striker around, so it was just a matter of endurance.  When you punch, REMOVE the chisel EACH time and turn it around.  Otherwise it would jam in place.  To do a better job in the future I would prefer to have 2-3 chisels available so I could rotate them and let them cool a bit.  

By the time Tim my striker turned up, I had been at it about three hours, and was about an inch deep from both sides.  Tim and I continued for another couple of hours until annoyed, I drove the chisel harder than before and Jammed it in place.

We spent a feverish few minutes trying to remove the chisel: during this time I saw my presentation at the spring conference: Could I pretend the embedded chisel was intentional?  "Hey everyone: look at my handle!"  🙂

We managed to get the chisel out by driving a drift from the other direction.  The chisel tip had bent inside the head either when I jammed it, or hit it with the drift from the other direction.

When I looked into the hole, the light dawned on me: for the last couple of hours, Tim and I had been pushing a steel slug back and forth in the bottom of the hole.  The jam was where the chisel began to push through to the not perfectly aligned other hole.  ONce it got close to black heat we drove the slug out, shut the forge down and quit.  

So:

1) measure the depth as you punch.  (no Kidding!)

2) punch lubricant is your friend, but if water based such as Renite, it will quench the chisel: be sure to let the chisel cool.  (had to grind a new tip on it when it cracked: turns out it's air quenching steel!).

3) When you are close to the center, the hammer will hit the chisel with a more squishy feeling.  That's the center: Stop!  Cool and drive out the slug!

4) Have a couple or more chisels to rotate.

5) practice with a striker a few times so you know to expect the blank to go odd directions.  🙂

I am still working on a jackhammer chisel bit as a drift, so I have stopped working on the hammer for the moment.

--jason