Heat treating a sword using a water quench is a tense affair as the sword my crack and many hours of work may be lost. This video shows heat treating a wakizashi I made from forge welded cable that was folded several times. The Japanese differential heat treat calls for coating the back of the blade with a clay layer that retards the quench and allows the covered part of the steel to remain softer. The border between harder and softer steel becomes visible as hamon. Although, the heat treating was successful, the blade developed a welding flaw and at this point it looks like 20 hours of work might have been lost.
Entries tagged as wakizashi
When examining a traditionally forged Japanese sword, the steel structure (hada) often looks like wood grain. This structure is a result of folding and forge welding tamahagane. To simulate such hada without using expensive tamahagane, I took 24in of 1in diameter steel cable and forge welded it into a single piece of steel. That steel was then folded 7 times with some surface manipulation and then forged into a small wakizashi. The picture shows the tang after the scale was removed, polished and then lightly etched to show the grain. The steel structure seems similar to mokume hada. Now, I just need to find the time to shape, heat treat, polish and mount the sword. Expect progress pictures as work permits - probably in a few months.
I just finished taking the 5-day basic forging class taught by Michael Bell at Dragonfly Forge. The wakizashi in the picture is the result of it. The blade is about 18in long and was forged from forge-welded cable. The forge welding of the cable conducted by Michael and his son Gabriel took the better half of the first day. Afterward, the steel was forged into a sunobe which has the basic taper for the tang and point of the sword. We then forged in the ji and the shinogi ji. The remainder of the time was spent grinding in preparation for heat treatment. Before the clay was applied, we draw filed the blade so that all file marks were parallel with the edge rather than the perpendicular marks left by the belt grinder. Applying the clay was a three step process; a light coating of the whole blade, applying the ashi lines, and then coating everything that should remain soft. You can see the ashi and where the clay was applied on the middle picture. After heat treating, the blade took on a nice curve and it was back to the grinder. During the last day there was a little bit of time to polish on stones which showed hints of some very wild hamon as well as some mune yaki. The whole class was a great experience.