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ScKaSx

Mokume Gane for Beginner

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Hi All,

 

This is my first time to the forum and the reason I joined was to get help with Mokume Gane. I wanted to make a Mokume Gane ring for someone and need some help. Firstly, I am a beginner to jewlery making but have experience with metal work (ie. I have access to mill, lathe and welding equipment). I also have access to high temp furnaces (w/ temp controls). I have sorted my questions by the fabrication steps:

 

1) In regards to the billet, what combinations of metal are no-no's, and where is a good source for the raw material? Since the furnace temperature for fusing depends on the metal compositions I wanted help with different metal combinations. I was leaning towards a combination of red gold and white gold, anyone have experience with this? As for what I want it to look like, please refer to Fig.7 here (http://www.mokume-gane.com/Pages/What_is_Mokume.html). I like more of the earthy look as opposed to the shiny look that silver and platinum brings.

 

2) I was planning to fabricate torque plates for compressing the billet while it fuses, will stainless steel do the job? How much torque should be applied to the plates?

 

3) In regards to the fusing, the furnace I was planning to use has a max. temp of 1550 F. Given the combination of metals suggested what temperature and how long would I need to heat treat the metals? I have a preference for diffusion fusing since liquid fusing sounds like it requires more experience. Also, where is a good source for the steel bags?

 

4) The major question mark in my mind for doing this is how to flatten the billet after its been fused. It seems to me that the billet should be less than 1cm before I can begin 'patterning'. Should I plan for the initial billet to be less than 1cm before I fuse (what is the normal dimensions for the billet before and after fusing)? Also what should the dimensions be before patterning? Furthermore, after patterning, how do I continue to flatten the billet to the thickness of the ring?

 

5) I saw another topic on this forum in regards to soldering the finished ring strip. There didn't seem to be a concensus on the type of solder to use. Obviously it will depend on the metal composition chosen, but what is the best way to do it so that the pattern looks continuous?

 

Sorry for all the questions, but the information online seems to be alittle thin in regards to the specifics. Please reply with as much information as possible, even if you feel it is unimportant. Thanks!!

 

Cheers,

ScKaSx

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I don't have any experience about this but I can share my thoughts.

 

Stick to two types of metal, it should be easiest considering different melting points. If you use more the metal with the lowest melting point should(most logical) be between the other two(or more) types of metals, so that the metals of higher melting point don't touches because then they may not stick and if you should get that high in temp the "lower temp" metal will melt and may run away and ruin it all.

 

Materials with clean flat surfaces fuses together easier under pressure so tightening them good and even should work best I think. And I've heard that with a "very" flat and clean surface and enough pressure you can fuse metals together in room temperature. So with better prepared pieces the lower temp you need.

 

About the clamps to compress the billet I think you could use normal steel because the only touch the outer surface that you would grind of anyway so from that point of view it doesn't matter. If you have stainless it will warp and be more sensitive to heat and may crack in the cooling and things like that, and if you also have stainless bolts they most likely will get stuck when heated and you will have to cut them off.

 

To work the material you can forge it with an hammer and anvil or/and use a roller or wire drawing plate.

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First,Ignore most of what Henrik has posted.

 

Second, do you have access to an oxy-acetelyne torch?

 

Third,i'll get back to you when i'm more awake and remember the video links from another forum discussion.

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First,Ignore most of what Henrik has posted.

 

Second, do you have access to an oxy-acetelyne torch?

 

Third,i'll get back to you when i'm more awake and remember the video links from another forum discussion.

 

Haha, thanks. Please teach me too :rolleyes:

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1)Bad combination for mokume is any stack where silver comes into contact with brass.

What karat of gold are you considering,14k or 18k? The white gold needs to be palladium white gold,nickle white gold tends to work harden fast and becomes brittle.

One source for metals is Rio Grande in New Mexico.

 

2)Torque plate fusing takes a lot of time,maybe think about torch fusing or hard soldering the sheets of metal.

A few copper/silver practice billets could save you money and heartbreak from ending with a pool of gold.

 

Torch fusing mokume

 

3)see #2

 

4)refer to #2 and #5

from the video link on #5,see side bar for more videos from the same source.

 

 

 

 

5) video link to solderless mokume ring technique.

 

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Hi All,

 

Thanks for all the good replies. I am currently planning to do the ring soon, and YES I do have an oxy-acetelyne torch. DanM the resources you listed are very useful and I will try the methods I saw there. The link you show for the solderless ring, is impressive. However, I was wondering how difficult it is to form after bowing it in half? It seems like there could be trouble at the ends when trying to make it completely circular (the videos didn't show the shaping it into a ring part).

 

As for the material, does anyone have a good source for thin strips of precious metal that I can buy? Also I definitely will be using 18K gold, as for the other metals I haven't decided yet. Does anyone know a deep reddish non ferris metal that could work? I want a good contrast in metals but I also don't want to use silver because I want the colors to be deeper and darker reds/yellows (like a wood grain). Also what would be a good number of layers to start with if each layer is ~1mm thick and surface area of something like (3mm x 50mm)?

 

Anyways, keep the good comments coming! Thanks!

 

Cheers,

ScKaSx

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There appears to be one video missing.The ring blank is opened enough to have a ring mandrel inserted,the original holes drilled to enable the sawing help to prevent splitting of the material.The ring is hammered onto the mandrel for shapeing a little at a time with good annealing during shapeing.

 

Rio Grande,Hauser and Miller,check your yellow pages for a precious metal supplier.Red gold is the only metal that will stay a red color,14 red will have a better red color than 18k red.You could use copper although it will oxidize from bright new penny look to old penny color fairly fast.

 

6 layers should give a good pattern,a tight twist compared to a slow twist will give you more detail.

 

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DanM,

 

Thanks for all the information, you have been very helpful. I was going to use to the torch for the fuse, but have decided to use a mini hot-press i have in the lab. I was just wondering, if you know what pressure would be good to take the hot press to. I was hoping you had a feel for this for either a copper/silver combination or yellow gold/red gold combination? I was planning to take the furnace up to 70% the melting point of the silver (since it has the lower melting point). As for the pressure do you think 1000 psi will do?

 

Cheers,

ScKaSx

 

There appears to be one video missing.The ring blank is opened enough to have a ring mandrel inserted,the original holes drilled to enable the sawing help to prevent splitting of the material.The ring is hammered onto the mandrel for shapeing a little at a time with good annealing during shapeing.

 

Rio Grande,Hauser and Miller,check your yellow pages for a precious metal supplier.Red gold is the only metal that will stay a red color,14 red will have a better red color than 18k red.You could use copper although it will oxidize from bright new penny look to old penny color fairly fast.

 

6 layers should give a good pattern,a tight twist compared to a slow twist will give you more detail.

 

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The process is a combination of heat and pressure.Once the metals reach fusing temperature it doesn't require much pressure.For copper/silver the fusing temperature is around 1445 F,once the molocules start moving between the sheets of metal it is a matter of time and presssure for the fusing.The fusing process is a fairly simple one,changing temperature and a "high" tech pressureis beyond my experience.Check the link below,James Binnion is doing work with high tech mokume processes now.

 

High Tech Mokume

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If you have access to a Hot press with controllable pressure then you can go the high tech route. Pressure is not as critical as temp when you go this way. In the high tech way (Solid phase Diffusion bonding) Pressure is there to ensure that the surfaces of each layer make full contact with each other so the grains can grow together across the weld zone uniformly across the entire billet.

These alloys are soft and get softer when they are hot. They do not provide much resistance to pressure while hot. So unless you want to squish the billet right off keep the pressure low. You can start out with enough pressure to squeeze the layers then you can tighten the stack when it has reached temp I would only apply enough pressure to reduce its thickness say 5 percent while its hot. That will make sure that the stack is making full contact through out the initial firing.

In Dans preferred method (liquid phase fusion) timing is very critical because you are generally going above the possible eutectic temps. In the high tech approach where you can control your temp accurately over a prolonged period you can work just below the Eutectic eliminating the risk of melt down altogether. This method requires longer firing times sometimes 8 hours or more at temp. Either method works fine. Solid state diffusion bonding is more finicky if ask me, but Liquid phase bonding is more touchy and requires a practiced eye to get the timing right.

Eutectic temps are derived from Phase Diagrams. When alloying two or more metals the alloy generally melts at a lower temperature than either of the parent metals. This lowest point can be looked up for any combination of elements present in your alloys. Find the lowest possible melting point combination out of the elements present and that is the temperature you have to stay under to prevent meltdown of the parent alloys when using solid state diffusion bonding.

Put Silver and copper sheet together and heat to 800C the two sheets will combine into a mushy semi liquid mess. This temp is well below the melting point of silver or copper. Pure silver melts at 961C. Copper melts at 1084C The eutectic for the two metals is 779.C If you fused these two metals at 750C there is no risk of melt down even if left at temp for days. If you go above the Eutectic temp then time becomes very important and the heat must be removed the moment the billet begins to sweat. This is when the Eutectic alloy is forming between the sheets. Wait a moment too long and enough Eutectic forms to actually run out of the billet as a liquid.

Phase diagrams can be found here and there on the net. Binary ones are common, but tertiary diagrams are harder to find. If you have access to a phase diagram book then you can look it all up yourself (expensive book). You don't really need them as you can find all of the information you need already published in Mokume gane books (inexpensive books). Precious Alloys, combinations, times, and temps. Its all published and waiting.

(Edited to add, sorry that is not all beginer stuff, but you sound quite advanced with your queations and no one else cares about Eutectics so I thought I would throw that out there ;))

patrick

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