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Mokume Gane


Fe-Wood

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I want to make some Mokume Gane. I'm hoping to make a sheet about .04"x6"x6" or bigger.
I've made a few pieces from quarters to about .06"x3"x3" with pretty good results but I can't get the size I want without stress fractures from dissimilar metal movement.

Anyone know of copper, nickel and silver alloys with similar melting and elastic properties? I can make a billet of about 4"x1.5" comfortably. In the stretching is when I have the de-lamination problems. I work the pieces hot until they become "stiff" and reheat to a low orange.

Any thoughts, ideas and sources would be gratefully accepted.

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Copper from what ive read, and experienced is a better cold worked metal. I usually heat till dull red, quench, then work untill it is hard again. Unlike other metals copper is annealed when quenched instead of hardened. I have only had experience with quarter mokume with about 6 quarters my max so YMMV.

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technically, copper IS like most other metals. steel is a minority about quenching to get hard, Just a FYI

also you didn't state if solid state fusion welding or soldering to join the laminates, that does make a difference in how hot, or cold, it should be worked. Or what metals you have tried.

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Steve-
I will be fusing the laminates. I don't know the exact makeup of the metal I've used for previously made Mokume. I have only used Quaters. So I assume nickel alloy of some sort and copper alloy. What I find happening is the nickel, while worked hot becomes a bit softer than the copper. I think this puts more pressure on the bond and can cause it to fail.

My goal is to make sheets that I can then raise into other forms. I intend on making the sheets while the billet is hot with a power hammer and a rolling mill and then doing the raising work in a cold state. I will need really good bonds between the verious metals and similar working propeties within each laminate.

I hope this helps clear up what I'm looking for...

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I would think that the nickle sheet is going to be a lot stiffer than the copper, so that could cause problems when spreading it over a large area and raising the shape?

I've made 3x3" billets of 20 layers of 1mm copper and brass sheet with mixed success. The first billet was fused, drilled and squished to produce 1/2" thick blocks for guards. The second billet that size was going to be spread out and restacked to get a higher layer count, but I didn't get the sheets fused well enough to successfully draw it out :( Mind you, it probably doesn't help that I was doing the drawing by hand as i don't have a power hammer, press or mill (fused the billet in a bottle jack press)

The key with making the stuff is everything needs to be squeeky clean and with no air gaps before you start. The even heat and pressure whilst fusing. Then its down to the mehanical properties of what you have in the billet!

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I spent some time read up on this stuff last night.
I found an interesting article by James Binnion:http://www.mokume-gane.com/Papers/SantaFePaper.pdf

I am going to try his "tork press" idea. It seems like what he is doing is applying pressure to the stacked laminates while cold and when it reaches proper temp for difussion welding, pull it out of the furnace and pound gently.

I have ordered a couple feet of Nickel Silver, so we'll see what happens...
The composition of the Nickel Silver is (65% copper, 17% zinc, 18% nickel) The copper I'm using is C101 oxygen free.

Edited by Fe-Wood
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So, I thought I would do a comparison on a couple different alloys of Nickel Silver. As shown above, the stuff I bought is 65% Copper, 18% Nickel and 17% Zink. Turns out the "common" Nickel used in coinage is 75% Copper and 25% Nickel, no Zink. I hope the addition of Zink isn't going to be a problem.

"For modern coinage, many alloys were made and tested in the search for the best substitute for silver. The Swiss and Belgian coins were made of an alloy 75% copper and 25% nickel. That alloy, cupro-nickel, is today the single most common alloy of nickel for coinage in the world." Copied from NiDI Status Report #6: The Colour of Money (1998)

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Not to steal the thread or anything.....well OK I'm stealing it.
I found this picture of a mokume gane ring and have been trying to think how the texture was done. I can't think up with the technique. I probably just don't have the correct tools to do this nor even know what the tools are.

I did give it one try:
Being hands on I made up a ring 'blank' (a thin strip ready to be bent into a ring) of mokume gane out of quarters and some copper sheet I had lying around. I tried just drilling some closely/randomly placed holes of different sizes and then acid etched after protecting the back sides and some of the high points of the blank. Didn't really work. It looks a little too much like a manufactured moon surface than the random canyon look. If I can find the camera I'll try and take a picture of my try.

 

Photo property of James Binnion

17902.attach

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O.K. if I get technical about the use of the word "fusion"? Fusion means to melt (except in nuclear terms). Pressure welding is "solid state" welding, while arc and gas welding are "fusion welding". There should not be any fusion going on in pressure or forge welding.

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I have used two techniques for the "grain" structure. One is the topographic method of cutting and grinding into the surface and then forging smooth. The second is a combination of the first and then twisting the billet. The results have been very interesting.

Grant-
Get technical, Given my brief knowledge of this stuff all corrections and explanation of proper terms are always good. So, from my current understanding, I want to do "solid state diffusion" welding.

I picked up a very informative book on ebay: "mokume Gane" by Ian Ferguson. He gives great methods and procedures as well as the history of the production.

Now, if only I had the time to try some of them....

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Just wathced Ryan Johnson at SOFA.
He did mokume from 15 quarters and made a heart pendant.
He said quarters mokume was for when he got up and remembered he had a birthday to go to and forgot to get a gift other wise he used shim stock copper and nickel silver or silver or brass ect. He recomended trying to get 10 thousands thick stock and do about 80 layers that way you had more layers to pattern and you did not have to draw it out as much.
He did not clean the quarters but said you had to scrub the sheet clean so it would laminate better.
I did 3 billets of 15 quarters but have had delam problems as the quarters only get so big before I start getter edges to show up in the pattern and then delamination.
I may try a stack of less quarters or go to 50 cent pieces.

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  • 2 weeks later...

781-
How much and how hot are you working the billet? I was able to take 10 quartersa and work it down to about 1/16-" with no delam problems. Iworked it in a high red heat until it started to work harden. I've always wondered about cleaning the coins, seems the texture help with the displacement of the oxidation somehow. I also use a vice for initial welding.

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Copper from what ive read, and experienced is a better cold worked metal. I usually heat till dull red, quench, then work untill it is hard again. Unlike other metals copper is annealed when quenched instead of hardened. I have only had experience with quarter mokume with about 6 quarters my max so YMMV.


Actually there are two separate issues, Annealing and Cooling rate from annealing temperature.

Pure copper along many other metals do not require any particular cooling rate when quenching from annealing temperature. Air, water oil it doesn't matter one bit. Some metals like steel, sterling silver, red golds etc care a little bit or a lot about how you cool them. But the annealing or re-crystallization itself is taken care of by the heat and the time at heat. The question is whether you will harden them during cooling by the improper cooling rate. Edited by jbin
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Well my guess is that they are doing their layering very clean and even and so they can use a foredom or similar tool to carve the structure. I don't think there is really much manipulation of the material involved just topographic relief carving.


Yes and no, Yes it is "just" carving with a bur that gives that texture but No I manipulate the hell out of that material to get it to the point where I carve it, as that is a seamless band that started out as a flat laminate stack.
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Yes I have made pieces of sheet in the 7-10" diameter range. It is a lot of hammering by hand but if you have a 25lb little giant or small air hammer with clean dies you can do it much faster. The sheet for this teapot was hand forged, now I have a couple of small power hammers, much better :-)
The biggest problem is getting even, thickness (.040) sheet . I found that a air planishing hammer is an excellent tool to follow the power hammer with. It allows for a much smoother final sheet. I am not a fan of nickle silver or cupro nickel alloys as they are a bear to move, very stiff. I also have had some problems with hot cracking of nickel silver while forging. Copper nickel alloys are better if you can get a hold of them as there is little or no zinc in them where the nickel silvers have a a fair amount of zinc which makes for trickier hot forging.

I am glad you like the rings, my favorite clients are other crafts folk.

Jim

18295.attach

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If you make a stainless piece of channel 1" on each side, and a smaller, 1/4" x 1" channel to fit on top, you can encapsulate your billet. Stack it in the deep channel, place the narrower channel on top, compress it with clamps so it's tight, then slot the ends of the small channel and fold them down. Next weld the channel all around to encapsulate the billet.

Weld a handle on it.

Take it to about 1675 and soak for at least 20 minutes. It won't hurt it to soak longer, but don't be impatient with it.

Pull it out, take it to a power hammer or press, and complete the fusion process with pressure. The stainless will peel off when it cools. Just grind the corners away.

Make sure your billet is clean and dry. Stagger the layers however you want, just keep them clean. Coat the bottom of the channel, and the bottom of the top channel, with white out before laying it all up. The stainless won't fuse to your billet.

I've probably explained this poorly. Send me a PM for more detailed instructions. I've been doing some art classes at the local CC so I can make higher end knives and learn some new stuff. The teacher found out I make mokume sometimes and expressed an interest, or real longing to make some. so we had a mokume party here yesterday. We did 6 billets that started at about 3/4"h x4" long, 1" wide. Out of 6 billets to start, we had 6 good billets. It was fun.

Since there were a couple of kinds of brass involved, we kept the temp at 1675 to avoid melting. That was in a Paragon furnace. My 25 ton press did the rest. Two billets showed some signs of just reaching melting point, with small brass droplets on the side. The others showed no melting. Melting it is a bad thing.

When completed we had drawn them out maybe 1/2" but they were 1 1/4" wide and 1/2" or less high.

Annealing is simple. Heat to a black heat and quench in water. It will work fast and easily that way. When it starts to stiffen, anneal again. If you overstress your joints will shear.

I hope that helps. This, BTW, is my first post.

Gene

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  • 3 weeks later...

ok did you guy make your billets with a flux? if so what kind or did you just clean the metals really well and what kind of forges did you guys use coal, charcoal or gas? i ask because i have a coal forge and was wondering if that if coal is to dirty for making copper billets and or forge welds
also is it possable to froge weld the copper with out the press plates?

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I've been using superior brand flux Superior Flux & MFG. Co.. I've used gas and coke for my forges and a vice or hammer to finish fusing the metal. Clean your parts REALY well unless you are using coins. For some reason coins fuse without cleaning, maybe its the nickel to nickel that makes it work so well. Bring up to red and coat with flux, reheat and soak for appropriate time (determined by volume) and use hammer, press or what ever else you may have to crush together evenly.

James- Thanks for the info on the alloys. I was worried about the zinc. Can you recommend a supplier for copper and nickel only alloys? That is an outstanding tea pot. I have admired it in a couple of books. Thanks for the inspiration.

Gene- Do you have pictures you can show? I think I might get what you are talking about. Pictures would clear up any questions.

Thanks for the replies guys- I thought this thread had run it course... Happy it didn't as these last few posts had some great info to share.

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