Questions about copper

Note that this hardness goes away as soon as you anneal it, which is a necessary step in the hammer techniques listed above. As log as you are simply carving away unneeded metal, and not trying to change the shape significantly, you will not need to anneal it, and thus will not be losing the hardness.

Good Luck, DoN.

Mine is a typical mid-war army shin gunto, but it's unusual in being a couple of inches longer than my other shin gunto that I've left in their original mounts. It's about the right length for a katana for me.

That's the plan. The first set of saya (and a white saya) are pretty much finished, I just need to do the mounts. I doubt if this will be the only set I make though. I'm more of a woodworker these days than a metalworker and I enjoy the finishing work on them.

This set are made from local-grown lime (linden, almost the same as basswood) and the process for making them is described pretty well in Leon Kapp's highly recommended book. It's simple enough and painstaking enough to be quite slow and restful. Making a good handle core is much harder, if you plan to use it for iaido and really want a working fit. I can't work with urushi lacquer in this country (wrong climate) and although I've a friend in Vietnam in the lacquer trade I choose to use shellac instead. The black is a commercial dyed shellac, the red is a blonde shellac pigmented with locally-mined (Clearwell Caves) red iron oxide (sometimes I use purple iron oxide too).

I was given a couple of rayskins for Christmas, so I might finally get round to wrapping the hilts! I braid my own kumihimo for making sageo cords, but I still need to learn a flat braid technique for the wrap itself. This will either be a flat braid on my marudai, or else making a takadai frame for braiding wider flat braids. There's also the full armour project for one day and that's going to need a _lot_ of braid! I might cheat and use a Norse tablet weave technique instead to make flat braid -- I've also been developing a crank-driven tablet loom for quick production (I know a lot of vikings and they all want braid).

Whatever you do, don't use stripped out kernmantel braids (paracord) for a hilt wrap you're going to use for iaido. The tubular braids "roll" internally and you just can't keep them tightly wrapped.

Another job for the rayskins is to be glued down onto something wooden, lacquered smooth and black, with the surface rubbed down to expose the white circles in the rayskin. I've lots of ideas for that...

Just looked - mine's a Vallorbe (blue plastic handle). They make the best files too.

I think I could do it in silver, someone better could do it in copper, but I couldn't do it in copper myself without wrinkles. So what I'd do instead is to make it in two pieces and silver solder them together, much as I've done with the iron ones. Form a shallow oval dish by sinking, then solder it to a tubular or slightly conical oval tube, rolled up from a strip.

Read Oppi Untrecht and the process of _raising_ a silver jug. Once you've seen the "flailing jellyfish" / "umbrella in a hurricane" phase that that goes through, and then gets worked flat again into a smooth surface, then you'll believe anything is possible if only you practice and get enough shiny new hammers.

You're right though - the wrinkles would be the limit here, hence the soldering-up idea.

They ate fugu too, but that's no reason _I_ have to do it. Copper is soft because it's a pure metal and an alloy is always going to be a better deal mechanically. Lately I've been lost-foam casting 10% tin bronzes and trying to make bronze age daggers and swords. The difference in hardness is staggering and the colour is prettier too. It wasn't the best shave I've ever had, but I did just about manage to shave with one of these. For the small quantities you need here, you can afford your pick of metals.

Most of my copper is recycled water heaters, just because it's cheap. It's only thin gauge though, as thick copper isn't common in scrapyards. So if you're having to pay out to buy sheet, then get the best choice you want -- you're going to be paying for it whatever! (look at the model steam community for supplies here).

I think my next tsuba might be forged titanium, just because I love hand-forging it. My favourites are still the simple disks cast on cuttlefish though.

I'd be tempted to not cut any away and go for a surface-worked engraved or punched design with just a few small holes (like the iron "armourer" styles). Tsuba designs were generally either near-solid, or near-empty. If they cut them at all, then the tendency was to cut them to ribbons.

The trouble with steel is patinating it. I love Japanese komai work, precious inlays into black or purplish iron. You just can't reproduce this in steel, the colours are nowhere near right. The armourer black styles are do-able, as are the burnished and blued highly-worked styles, but you can't get that inlay on black style to come out right without the right material.

I've heard of that process. Scares the feet off me, even today!

You can raise that much depth on a small piece of copper without too much trouble -- it just takes repeated courses of hammering and annealing. You hammer out the wrinkles at each stage as you go along, meanwhile increasing the depth. The key is getting enough stretch from the bottom part before trying to turn in the top. A sinusoidal stake and plastic mallet like are used for anticlastic raising help in the tight spots. I've turned a 2x2 inch piece of copper plate into a spherical object by rolling adjacent corners in opposite directions. Hammering on the sinusoidal stake helps stretch the inner parts enough to get the required depth. Don't try to close in the top until you are almost done, otherwise you can't get access to the inside to stretch it enough. Near the end, start shrinking the top in. Keep annealing anytime the metal starts getting hard to move.

Bob

You may already have these Tsukamaki related links, but what the heck... Tsukamaki Article from JSS/US:

Probably the best book on tsukamaki is "Sword and the Same" by Hakusei & Inaaba. I only found one copy available. It's a used copy and the price is $125.00 at Amazon.

If I decide to try tsukamaki I'll just buy the ito from Fred Lohman

Well, I'm going to try making it in one piece. I may even try a few times. Otherwise, I'll try going the two-piece route. When you say "silver solder", do you mean brazing?

I may try something a bit easier. Something like this simple cutout design:

BTW, if you get bored you can check out my photos at:

Thanks, I've seen those two and still have them printed out in the sword binder. It's certainly hard to find information on tsukamaki

I've heard of this, but it's so rare that I've never even seen it.

That's if you're in the USA that is. I did price up getting some from Japan, but it still seemed expensive. Of course after I'd braided my own sageo, I started to realise why...

No, it's a different process. Solder costs more, but the process is easier. Silver solder uses the same sort of torch and firebrick hearth, but the solder has low viscosity and flows rapidly by capillary action. You usually prepare the joint with flux and snipped-off "pallions" of solver, then heat it up. When it gets to temperature, there's a brief flash of silver and it's done and ready to be pickled in acid. Brazing needs to be worked around the joint manually, poking the filler rod in as needed.