The making of... Sanmai Cable Wakizashi
When I first saw Antonio's design for this project I immediately fell in love with it. It was the simple design elements of the aikuchi fittings and the choice of materials that called my attention to it. The contrast between the black horn and the Amboyna wood should turn out great.
The final choice of wood, Amboyna, was decided by the client, Jeff Larsen. The difficulty was in finding section of wood long enough that was also rich in burl figure as requested by Jeff. It had to be at least 23 inches long. The wood was so difficult to find that it will make a statement for future generations when looking at this blade and wonder about the uniqueness of a continuous piece of wood of this quality. For this reason, a choice was also made to stabilize the wood. Burl woods are notorious for their tendency to crack and warp over time. Stabilization was chosen to minimize those risks.
The neat thing about my forging shop is its portability. Since I have a limited space for work and live in a residential area where it would be unsightly to have this kind of equipment on open view, most of my stuff is on wheels, so that I can easily take heavy equipment out and back in to my one-car garage shop.
THE STEEL CABLE
This is a one inch diameter cable. MIG-welded at the ends to keep the threads from unraveling and cut to lengths of about one foot. I love working with cable. It is always a challenge to avoid cold shuts since there are many surfaces to weld and inclusions can occur as a result of dirt remaining in the cable from its previous use. I prefer to use recycled cable and do a good degreasing prior to welding.
I have recently built a new forge. Every time a build a new forge I am trying to improve on the previous design. This forge gets hot enough to melt a piece of machining graphite that I use to line the bottom as an flux resistant surface for welding. I have a detailed description of how I do my forge welding here.
In preparation for welding the sanmai billet I have cleaned up the cable steel bars with the grinder. A piece of 1050 carbon steel will become the core steel and the welded cable bars will be the jacket steel. Then it is all welded into one single bar and drawn out into a sunobe.
The picture above shows the bar drawn out to a 1 inch by 3/8 bar. Unfortunately I forgot to take a picture of the sunobe itself. From the time I figured out how to forge a shape starting from a sunobe I haven't gone back to the old ways. The sunobe makes everything easier for me during the rough forging of the blade's shape.
I use a marker and draw on the surface of my old banged-up anvil the profile of what I am trying to make as a guide. Of course I found myself redrawing it over and over again as it erases from working on the anvil.
And finally here is the rough shape of the blade after forging. I set my drawing of the project beside to compare. I like to draw all projects on paper before I actually start doing anything. It is kind of my way of visualizing what I plan to do and it becomes a reference point for later.
GRINDING AND CLAY-COATING
These pictures represent the rough grinding of the blade. First removing the forging marks, then profiling the blade and finally grinding to 220 grit. I used to do this by hand with files to make the blade perfectly smooth and try to avoid any stress risers to prevent cracking during yaki-ire. Then I had a chance to see a blade of Yoshindo Yoshihara just before clay coating and realized that he was the least worried about stress raisers.
This is a suguha clay layout. I decided on that after noticing that the design intended to show the cable pattern above the hamon. I think this will bring that about. I have stepped away from using satanite. Not that there is anything wrong with satanite. It has done its job for me before but as I get more picky about the design of the hamon and I develop better control of this, I needed a more plastic clay. Something that will follow my spatula during the application process and will be smooth and not so bumpy. I have read the books about what the Japanese smiths use and I saw Yoshindo applying his clay and got a feeling for the plasticity of his mixture and I have now my own recipe trying to achieve those results.
Yaki-ire is the time when you prepare to give birth to the blade. For me it is a ritualistic process. I start by clean-up the shop. Then I get my water tank out and heat the water to about 110 degrees F. Get my heat treating oven out and preheat to 1550 degrees F. Then the blade goes in. I have enjoyed this oven design since I made it. Before I built this oven, I will have to keep going back and forth in the smaller forge where you could only heat one section of the blade at a time. The unevenness of the heating using the old method was responsible for warping and cracking.
MAKING OF THE FITTINGS
I start by drawing the fittings in the computer to get perfect oval shapes. Then print them and glue them to thick cardboard paper and cut the shapes. Those will serve the purpose of guiding the profiles for translating to metal or horn. Then I select the pieces of horn and copper to be used and rough-shape them. This project will use a total of 9 pieces: 2 copper seppa, copper habaki, horn tsuba, koiguchi, fuchi, kashira, kojiri and mekugi. I am thankful to the Japanese for having given us words to describe each one of those parts.
I have documented the making of the habaki in a separate tutorial.
The horn tsuba is finished. I like working with horn because it takes a nice polish. Even though not all pieces of horn are uniform, the whitish streaks produce a beautiful iridescence when highly polished that gives each piece a unique look. The seppa are finished out of thin copper plate and polished. From now on I can let go of my cardboard pieces and use the seppa instead to guide the rest of the profiling for the tsuka and the saya.
MAKING OF THE SAYA
I received the amboyna after it was stabilized, selected a piece for the tsuka and another the saya and started to carve out the hollow for the nakago. As I started chiseling I encountered a couple problems. There are some voids in the wood that the resin did not fill. They are a minor problem since I can use superglue to fill those in. The other problem is more serious and is inherent to any burl wood. The stabilization has made the wood less brittle but not completely. Since there is no defined grain in the burl wood, even the sharpest chisel causes chipping of the wood rather than a clean cut. The chipping is not a problem for the nakago but unfortunately it will be a problem for the saya. The channel that I carved does not have a smooth surface. The solution to this is to carve a larger channel and line it up with a piece of poplar wood. Poplar is what I normally use to make saya and is a nice wood with good grain that is very close to ho (magnolia) wood. After I glued the poplar I carved it to the shape of the sword. This will not be visible outside. It takes more time to do it but I think this is the best solution to make things right. I should had anticipated this problem but I had higher expectations from the stabilization process to prevent this issue. Unfortunately it did not. On the other hand the stabilization process has made the wood heavier and stronger and is not likely to warp or crack in the future. In the end this will be even a better saya.
The amboyna and the poplar wood. The amboyna is carved and waiting for the poplar lining
This shows the saya sections carved and lined with poplar.
This will be the design of the kojiri and kashira based on a computer drafting.
THE POLISHING PROCESS
I start by removing any remnants of the yaki-ire on the grinder with a 220 grit clean belt. Then I move to a hand sanding process. Starting from one step back at 120 grit in one direction, then 220 in the other, then 400 straight along the blade, then 600 at an angle, 800 at opposite angle, then 1000 straight, then 1500 straight, then 2500. At that point I test the blade for sharpness by slicing paper. Then I use a hybrid polish to imitate the Japanese process of finger stones. I use a combination of steps that include lemon juice, vinegar, paste polish, pumice, Windex, Fantastic and nugui. The final results that I obtain are very similar to the Japanese but using modern methods. It will show a distinct hamon and the pattern in the hada from the folding process.
The full blade polished the modern Japanese way. Good contrast and definition.
The tsuka was completed after quite a bit of experimentation on a scrap piece of the wood. Since it is my first time working with wood that was stabilized with this kind of resin and I did not know what to expect, I had chosen to test different ways of finishing the wood and the horn aiming at the best result. In the end the wood stabilization resulted in a beautiful finish for this amboyna burl wood.
The wood is roughly shaped with rasps and finally hand sanded from 120 grit to 220 to 400. Then the voids in the wood are filled with superglue and when needed with epoxy mixed with dust from the sanding of the wood and occasionally with little chips of the wood itself. Then re-sanded to 400 grit, then 600 grit. At that point I used a clear coat application that is followed by sanding at 600 grit. Several more coats and moving up on the grit to 800, 1000, and finally 1500. Then buffing to give the final shine.
After completing the tsuka, I drilled and corrected the orientation of the mekugi ana and made a horn mekugi that will be inserted at an angle to secure the blade in place. Everything fits nice and tight. I put the seppa, tsuba and habaki together to see what the final look of the blade will be.
I carved the mei after doing the yasurime (filing marks on the nakago). I chose to write my name in Katakana and Kanji. It says "Made by Jesus" in one side and "Spring 2006" on the other side. The date is inscribed in the modified modern dating system.