I have been using premade billets of mokume gane. Mostly with copper and sterling. From one supplier the stacks are created with both sides ending in copper. I've tried soldering a thick sterling layer to one side - with limited success. After cutting in a pattern, then flattening and finishing, sometimes small sections of the added top silver layer will chip off.

I don't think I'm getting a great bond in my initial solder. After reading your replies, I think I need to work better at getting a perfect bond, with no air pockets.

I'm just not sure of what techniques I should use when soldering flat to flat metals. Should I use binding wire to clamp the sheets. Is paste solder best?

Thanks,
David

David,

As I noted before, the things that are critical for making mokume gane are fit, cleanliness, temperature, time and pressure. For soldering, you can narrow that list to fit, cleanliness and temperature.

Solder flows by capillary action, so the pieces must fit closely enough to sustain capillary flow of the molten solder. For general purposes, a fit of +/- .005" is desirable. That's about the thickness of a piece of glossy magazine paper. In short, a damn good fit.

The pieces should also be chemically clean - no oxides, no grease, dirt, etc. I scrub with pumice and clean water with a drop of Dawn dishwashing detergent, followed by a rinse. Dry the pieces with a clean, lint-free cloth. then flux both pieces.

For flux, I prefer Battern's Self-Pickling liquid flux over all others. Handy and Harmon's paste flux is a distant second, and all others don't matter because I wouldn't use them. (We all have our little idiosyncracies, don't we?)

Put the pieces together and retain them in position. YOu can use binding wire, cotter pins bent like clothes pins, cross-lock tweezer clamps or just plain old gravity if your work surface is level. If placement of the two pieces is critical, by all means use some secure method of holding it in place and don't rely on gravity. When the solder reaches liquidus, things can get pretty slippery.

Speaking of liquidus - there is melting point and flow point, and with most metals these occur at two different temperatures. The melting point is actually properly called the "freezing point", since it is the temperature at which the metal just becomes a solid, (or "freezes"). Thus, this point is called solidus. Liquidus, on the other hand, is the temperature at which the metal is "liquid", or flows. This is the temperature that you need the solder to reach when soldering, while the metals to be joined are still at solidus or below. That's why there are different grades of solder. For soldering sterling to your mokume gane, you should use the highest melting point solder you can get away with.

If the mokume blanks you have purchased were made by solid-state diffusion bonding, as they should have been, then you can use grade IT solder to joint the sterling to the mokume. If you're not sure, then use grade Hard. If you use the Medium or Easy grades, then you don't have much leeway when later wanting to solder things together, and the joint may disassociate (break) when subjected to the stresses of forging or forming, since the lower meltin gpoint solder will be less malleable than the parent stock.

Hope this is of use to you.

Rich

I am a metalsmithing student at SIU in Carbondale IL. They did a study on mokume here some time ago and invented a technique in which you use a torque plate (2 pieces of steel with bolts in the corners). You place the metal you are bonding together between the steel plates and use the bolts to create the clamping pressure. After it reaches fusing temp. you hammer it while still in the torque plate and reheat and hammer and reheat...then take the torque plate off and hammer it some more. I recommend hammering it down to at least 10 gauge before you roll it, the thinner the better because rolling can cause the metal to stretch farther on one side than the other which can cause splitting. As for the pattern engraving tools are better than power tools because the bits can get caught on a layer and cause it to separate from the others.

You can get James Binnion's attention by posting on Orchid forums run by Ganoksin. You will find a lot of helpful information on Mokume in their archives as well, and then you can show us your successes.

While I agree with Rick about Steve Midgetts book as being exceptional it is also very very difficult to find and expensive. When recommending Mokume books I usually recommend Ian Ferguson's book which can be easily picked up on ebay for less than $35. I personally use 1" thick pressure plates to press the clean brass, copper, and nickel silver sheet together before placing in my gas forge for fusing.

Chris Williams

I agree that Steve Midgetts out of prink book is so costly only a few can afford the $300.00-400.00 usd they are asking for it..He needs to reprint it so bad as its hurting those of us that need it as mokume gane classes are almost impossable to find.Ive spent days on the web looking for classes to no avail.He does own the printing company to.

Ian's book imho is not geared for us but for the academia professors.sure theres info in it but its hard to understand.

Chele
Black Dragon Forge
Damascus BladeSmith/MetalSmith
Mountain City TN

That's an interesting approach and one that would certainly result in solid state diffusion-bonded mokume if all went right, which it sounds like it did. Well, right up until the other guy lost it, that is. That's a shame.

Rich