Questions about copper

Hi All,
I need to work a simple design into the surface of a 3" diameter piece
of 1/4" thick copper plate. I also need to form 1/8" copper sheet into
two different shapes; one is an elliptical cup shape and the other is
an elliptical ring. These two shapes will also have designs worked
into the outside surfaces. The only experience I have working with
copper is sweating copper pipe fittings, so I'm looking for suggestions
on how to go about this.
The material I have is C110 copper H04 (full hard) temper.
I have an oxy/acetylene rig, a Foredom TX flex shaft machine with a #30
handpiece and an assortment of burrs. I have lots of normal hand tools,
including a 4" jeweler's saw and a bunch of blades.
Let me give you a better idea of what I'm trying to make. These three
items will eventually be parts of a Japanese sword. The 3" diameter
piece will be the hand guard (tsuba), the elliptical cup shape is the
butt cap (kashira), and the elliptical ring shape is the hilt collar
Here are URLs to photos that show a set of parts that are similar to
what I want to make:
formatting link

formatting link

For the tsuba my original plan was to scribe the design onto the
copper, then cut it out with the saw. Then I would refine the design by
grinding, filing, sanding, and polishing. However, I have since
learned that copper can be difficult to cut and grind because it's
soft and gummy.
Some of my questions are:
1. How should I go about removing the material initially to form the
shapes? Will the flex shaft and burrs work for this, or should I try
something else?
2. How to form the ring shaped fuchi? I'd prefer not to have a
visible seam, if possible. Would it be better to machine it from a
3. How to form the cup shaped kashira? Again, I'd prefer no seam.
I thought about casting these from silver, but the last (and only) time
I did any lost wax casting was back in 1970. I don't have the
equipment for it anyway.
Any suggestions will be much appreciated.
Reply to
Loading thread data ...
Copper is sticky and soft, it doesn't machine with burrs or grind well, but is easily hammered.
Most copper ornamental work is repousse type (hammered from the back into a form) or engraved (scraped on the surface). You can make your cup-shape by repousse, and the ring can be cut as a washer, then hammered on a mandrel to make a ring.
It work-hardens, so soften it before forming (by heating near red heat, quenching quickly). Yes, I said quench quickly to soften... it isn't iron, you know!
Reply to
[The original technique for making these things obviously didn't involve a flex-shaft and burs. If you want an authentic result, it's best to use an authentic production method. I'm not Japanese or a swordsmith, but I'd imagine the tools used were basically hammers, chisels and punches of various sorts to start with, with files and gravers to finish. Some research on your part might be in order.]
[It's possible to make a ring without soldering, but it won't necessarily be even in thickness. Anneal your metal (heat to red and quench) and use the saw to cut out a doughnut-shaped piece. Then using a tapered mandrel, turn that into a cylinder by compressing the wide end and stretching the narrow one, using a hammer. If it starts stiffening up, re-anneal. Machining it could work, but it didn't sound like you have the equipment for that.]
[You can beat it into a depression initially, working from the inside, and then turn it over and beat it over a positive form, working from the outside. The decoration can be done as a mixture of repoussee and chasing.]
[Well, there are casting services you could use, if it's not important to use copper or direct metalworking. This would be a lot easier, and probably just as authentic. You can also cast them in a metal like shakudo (a copper-gold alloy), which has a coppery appearance, and was often used for this sort of thing (see
formatting link
for examples) Pure copper is difficult to cast, but there are various traditional Japanese copper alloys that would work well.]
[I'd say find out how these things were made originally, and adapt from there. I doubt the people who produced them had much more tooling than you do - probably a lot less. But they did know what they were doing with what they had...]
Andrew Werby
formatting link

Reply to
Andrew Werby
wrote: (clip) soften it before forming (by heating near red heat, quenching quickly). Yes, I said quench quickly to soften... it isn't iron, you know! ^^^^^^^^^^^^^^^^^^ Any way you cool it after annealing is okay. Quenching quickly is quicker, but otherwise it makes no difference.
Reply to
Leo Lichtman
I tested my steel burs on a piece of the copper. They did cut, not fast enough. I was hoping there would be some other type of cutting or grinding gizmo for the flex shaft that would carve away material faster yet still be controllable.
One problem (I think) is that both the ring and the cup are elliptical, not circular. Wouldn't I need an elliptical mandrel to form the ellipse shape?
Reply to
You're probably right about the tools they used, but I haven't been able to find any books on the subject. I've been looking for a while now too. Apparently, this was real top-secret stuff, only passed on from master to apprentice. Even modern day artisans refuse to share their techniques. If you know of any books on the subject, please let me know.
That sounds okay, but it's not a cylinder. It's an ellipse. I suppose I could form the cylinder, then flatten it out to match an elliptical template. Does that sound right to you? Or, should I try to find or make an elliptical mandrel?
BTW, would this technique require shrinking? I've read a little about shrinking silver with a hammer, but I'm having a hard time trying to imagine how it works. It seems to me that hitting the metal with a hammer would only thin and expand the metal and make the diameter larger. I guess I should get myself a good 'How To' book on silversmithing.
I'm thinking that casting them in silver would be much easier. However, eventually I would like to make them with Mokume Gane, so learning to shape them from sheet metal is probably best.
Reply to
The quick quench is for convenience. Allowed to air cool, it will still be soft. The point is, because there is no carbon cycle involved, quenching does no harm, and removes most of the oxides that are formed in heating.
Reply to
Harold and Susan Vordos
The basic techniques aren't that secret. It's the trade of a copper-smith and there must be books available. Lindsay or Camden-books would be my first place to look at. If I would think that I need a book. But to me, it only looks like a selection of chisels and punches, a hammer and an anvil or wooden forms. And some experimenting.
I'd also go with the way Andrew suggested.
Reply to
Nick Mueller
The Craft of the Japanese Sword
formatting link
Good book. Bypasses a lot of the mystic mumbo jumbo that gets passed off onto the ignorant as fact about the how's and why's of the sword making process from iron bearing sand to finished product. Explains the process as well as the various hands involved producing the the end product.
There is a fair bit of info on the alloys involved in traditional furniture for these swords, and lots of good pictures of finishes and textures, though some of them are not fully explained. Once you know what a process is called, it's easier to find the info you want, too.
This is a good book, IMO.
It also covers a lot of the politics that went on that resulted in the swordmaking industry almost dying out completely.
Have you looked at lost wax casting as an option. It's lots easier to carve wax than metal, as well as easier to put the wax back on if you are not satisfied with the results.
Cheers Trevor Jones
Reply to
Trevor Jones
I already have that book. It's good, but it only covers the making of the blade, habaki, and shirasaya. It doesn't say a thing about the koshirae (sword furniture) that I am trying to make.
As I mentioned in my last post, I have considered casting. It believe it would be an easier way to make the parts I want. Unfortunately, it requires equipment that I don't have. I also want to learn how to make the parts from sheet stock so that later I can make them from Mokume Game.
Reply to
You might consider checking with local jewellers supply houses to see if anyone does custom casting for jewellers in your area.
You provide the carved wax, they have the investment, etc. Usually they have a minimum charge, plus materials. I know of at least two outfits that provide this kind of service in Edmonton Alberta, so it cannot be too tough to find.
I think you might be looking at combining several techniques to get where you want to go.
As a ferinstance, you might find that you must first forge a blank over a mandrell, then carve it to shape, then solder or fuse other parts in place as required.
Sounds like an interesting project.
Cheers Trevor Jones
Reply to
Trevor Jones
I'm doing something pretty similar myself.
formatting link
formatting link
(Yes I need new pics on the better camera and it's all 2 years out of date)
First thing is that you're not going to make sword furniture first time round. It's your _sword_! You don't want crude workmanship on it. I cast about 14 tsuba before I was happy with a pair. So teach yourself some techniques first, then worry about the final manufacture. In particular you don't need to settle on final designs or techniques just yet -- you're in this for a long haul.
Copper is easy to saw, so long as you do it by hand. It's higher speed powered tools that have the problem. A _really_good_ Swiss jeweller's saw beats the pants out of even a good English one for sheer accuracy and controllability.
Grab yourself a couple of books and learn some silversmithing. Then do it in copper. For pieces of this size, copper and silver are much the same materials to work with. They handle slightly differently, but the techniques are the same.
Suggested reading is Tim McCreight's Complete Metalsmith and Oppi Untrecht's huge doorstop. McCreight is dirt cheap and everyone should have it. Untrecht is expensive and worth reading, but save your pennies first - it's not a beginner's first book. There are also some good books on colouring and patination for copper alloys (Mc Creight and the other big one)
Simple hammer techniques (sinking) will form any shapes you need for sword furniture, up to and including a Western bowl hilt. Kashirae are easier in silver than copper though, as you need it soft and ductile to get that much depth into something that small, without wrinkles. Tools are just cheap hammers re-ground with a cheap angle grinder and polished to hell and back. Work in a range of hand-carved hollows in a hardwood treestump.
I don't think I'd use copper myself. Bronze is stiffer and I really wouldn't like to use a copper tsuba in case I bent it in use. If you can find a local evening class in silversmithing there's a whole lot that will give you access to as well, including affordable supplies of silver.
My latest fitting set are tsuba in cast bronze with 10% tin, cast as flat disks in cuttlefish bone. Menuki are bronze, silver or silver gilt, cast in cuttlefish. The other fittings are gas-welded iron boxes which I'm teaching myself to do silver and shakudo inlay work on. I've also tried some with cuttlefish cast silver applique motifs silver-soldered onto iron, or more cast one-piece bronze done with lost-foam casting in sand.
In the meantime I seem to have become distracted with Norse stuff. Now I'm soldering wire filligree and granulations onto everything in sight!
I still haven't had much luck with lost wax though. Can't seem to get a good clean burnout of the wax and the mould blows back and either ejects the melt or is full of blowholes.
Reply to
Andy Dingley
have you tried out been a long time sinceI have been there, but it use to be a great resource...
Reply to
Michael S
When I was a kid, my father had an old gunto sword that he picked up in the Navy. It looked a lot like yours. He let me keep it in my bedroom on a rifle rack. It was safe because it was dull as a butter knife. Unfortunately, it was stolen in a burglary.
Are you planning on changing the mounting of your daisho from tachi to katana? I'd love to see how you do the saya.
I recently bought a 4-3/4" jeweler's saw frame and a bunch of Pike saw blades in various sizes. The blades were made in Switzerland, but the frame was imported from Germany. It seems to be well made, but I haven't used it very much yet.
Thanks for the book suggestions. I've been looking at books online, but it's hard to tell what a book is really like without being able to flip through it. I'll be going to the bookstore soon.
I think the piece I'm having the most trouble visualizing is the kashira (pommel). It's a small cup like shape. It has an elliptical outline, approximately 1-1/2" on the long axis, and 1" on the short axis. I'm having a hard time imagining how you could hammer a single piece of copper sheet into a shape like that. Whether you hammer into a depression or over a mandrel, it seems to me that the sides would have to end up wrinkled. I don't doubt that it can be done. I just can't picture how it's done.
Historically, tsuba were made from lots of different metals, including copper. The copper I have is C110 H04 (full hard temper). It has a Rockwell hardness of B50. I think the .25" plate will be strong enough, as long as I don't cut away too much material while making my design. Besides, I'm not practicing any JSA, and it's illegal to use a sword for its true purpose (no matter how badly some people need it.) It's doubtful that any of my swords will ever be used in anger. They'll just sit on their stand looking pretty.
I have some 1018 mild steel plate and sheet. I plan to make fittings with this also, but I wanted to try the copper first. I also have some C360 free machining brass, bit it's round rod, not plate or sheet.
LOL! It sounds like you caught a bad case of the 'creativity' bug.
I learned lost wax casting in high school. It was back in 1970 and I remember very little of the process. I do remember that we coated the wax with some goop that my teacher called "debubblizer". I believe it was to help the silver flow into the mold and prevent bubbles from forming on the surface of the silver. We didn't use centrifugal force or vacuum to get the metal into the mold. We used a jar lid that had a handle sticking out of the top. The lid was lined with asbestos soaked in water. We poured the silver into the mold, and then pressed the lid over it. The water would turn into steam and force the silver down into the mold. Now that I think of it, it sounds dangerous as hell. However, none of us ever got hurt. It worked like a charm too.
Thanks for the help Andy!
Reply to
I've thought about buying casting equipment. I'd love to, but I'm afraid of what my wife might do to me. LOL! I'll look around and see if I can find someone to do it for me.
Thanks for the info Trevor!
Reply to
Yes, I guess I need a book. I'm going to get to the bookstore and try to find a good book on silversmithing.
Thanks Nick!
Reply to
Yes, I have tried swordforum. Didn't have much luck though. It's okay. I don't really expect to pick up a lot of detailed 'HowTo' information in online forums. Very few people are kind enough to take the time to type a long, detailed post. But every little bit helps. :)
Thanks Michael!
Reply to
What he said. But I'd add "The Design and Creation of Jewelry" by Robert von Neumann to the suggestions of Untrecht and McCreight. I use it more than either. ISBN hardcover 0-8019-5671-4 softcover 0-8019-6054-4.
Reply to
Adam Smith

Site Timeline

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.