matt trout Posted September 30, 2013 Share Posted September 30, 2013 I have been making mokume for my damascus blades for several years. Thought I would post a photo of one of my typical billets (48 layer copper/nickle silver). This billet was made from copper pipe salvaged from a plumbing repair job and nickle silver sheets. I am using a propane forge and borax flux. After getting the billet welded up solid I draw it out the same as my damascus billets. Usually leave over a quarter inch thick so I can expose more layers by grinding. The drop point shows how it comes out as bolsters. I posted similar photos on another website previously but thought this forum might be more appropriate. Let me know what you think. Matt Comments and discussions welcome. Quote Link to comment Share on other sites More sharing options...
Fe-Wood Posted September 30, 2013 Share Posted September 30, 2013 Thats a good size billet! I'm assuming the light color is the nickel silver? Do the copper and silver start out the same thickness before laminating? I'm asking because I'm curious about how the 2 materials move in relation to each other while forging. Someday I would like to make some to spin into vessels. Quote Link to comment Share on other sites More sharing options...
matt trout Posted October 1, 2013 Author Share Posted October 1, 2013 No the two materials, sometimes three, almost always have different thicknesses. Most of my billets end up about 2.5 inches wide, 12 -15 inches long and 0.25 thick. Before drawing them out to thickness they are usually 2X2 square and variable length. Yes the light color is nickle silver. I have used copper, brass, bronze, nickle silver, and tool steel all in different combinations. I do not use steel in my mokume anymore - gives a very interesting effect but heats up in milliseconds when grinding. The copper transfers that heat very quickly right into your fingers. I get best results from combinations of alloys that are mostly copper (similar melting points). I believe the nickle silver is approaching 80% copper as a base metal in the alloy. The silver colored dots are where the nickle silver began to melt and squished or moved around while compressing the billet. Since I am doing this in a propane forge I do not have exact heat control - just eye balling it and scratching the surface with a punch to test the level of "sweating". Very difficult to describe how you know when billet is fully heated but not overheated. If you overheat the nickle silver will splatter/spew out from between the layers of copper. An exact temperature electric oven would probably stop most of this. If I were going to try and turn the billet I would probably change the overall shape and keep it square. Size is only limited by your equipment. For vessels I would think you would roll out the billet into thin sheet, heat and form, then solder/sweat the seam but I do not know. Glad to share any of my limited knowledge. Good luck, Matt Quote Link to comment Share on other sites More sharing options...
Wroughton Posted October 19, 2013 Share Posted October 19, 2013 Matt, Kudos, you're getting away with techniques that are usually doomed for failure (according to the experts). Especially using recycled materials that have to be worked into shape. I too like the contrast of copper and nickel silver. An electric kiln with digital controller will take some of the guess work out. holding at heat (or not), can be important. As you noted with your grinding, copper and some of it's alloys transfer heat quickly so "soaking" may be a detriment at times. Quote Link to comment Share on other sites More sharing options...
matt trout Posted November 12, 2013 Author Share Posted November 12, 2013 Thanks for the reminder on doomed for failure, I do occassionaly have catastrophic failures in mokume and damascus. They almost always occur when having one of those lapses in judgement ie. not doing what I know works or not paying carefull enough attention. I recycle materials on some things but never my damascus. To much work involved to risk it on unkown steel. I usually sandblast the copper and flatten the entire billet in the press cold before heating it. After 60 tons per suare inch it really doesn't matter what the initial shape of the material. Yes I need to build a digital controlled kiln for my annealing, heat treating and mokume work. I built several for heat treating stone for flint knapping but never got around to making one for my knife making. Some of the stone heat treatments have multi-day build up and soak times. It would make the process more predictable. Once you get the feel of it though you can tell when the billit will bond. Nice looking mokume piece in your photo. After thinking about it, I guess you could forge out a sheet and then just work it on the swage block just like making ladels or dippers. Maybe I'll give it a shot one day. Heat issue I found with grinding occurs when I use steel in the mokume. All Non-ferous billit does not heat up near as bad. Matt Quote Link to comment Share on other sites More sharing options...
windancer Posted November 13, 2013 Share Posted November 13, 2013 Purty stuff for bolsters! Dave Quote Link to comment Share on other sites More sharing options...
patrick Posted November 14, 2013 Share Posted November 14, 2013 I regularly forge billets 2x2x6 and 2.5x2.5x6. These are all made by the compression plate technique described by Steve Midgett in his book "Mokume Gane". The billets I forge are either copper/nickel silver combos or copper/red brass/nickel silver. Layer thickness can be the same or varying depending on the pattern desired. When I was first learning to forge these materials I used a copper bar as my gage. The copper could be forged just a little hotter than the mokume billet. I have never had any trouble with dissimilar flow rates of the various materials, but I have had some trouble with over heating as my forge tends to develop hot spots. If you are forging round our octagons you can also get layers shearing apart when you forge in the corners. Patrick Quote Link to comment Share on other sites More sharing options...
jbin Posted November 14, 2013 Share Posted November 14, 2013 Matt, nice looking bolster on that knife. If you are going to only be working with copper alloys in your mokume you really don't need a temperature controlled kiln, just an eagle eye and keep moving the stack around in the forge to try to keep the heat even. It can also help to turn your burner down some :) Quote Link to comment Share on other sites More sharing options...
matt trout Posted December 11, 2013 Author Share Posted December 11, 2013 James, Yes I agree, trial and error lead me to using all copper based alloys as being easiest and most economical. I do turn off the forced air on the forge so it is naturally aspirated and barely burning when making mokume. Getting heat to the core with out melting the surface is crucial. Making up some mokume and damascus belt buckles for christmas. Will post if happy with result. Thanks Matt Quote Link to comment Share on other sites More sharing options...
matt trout Posted December 11, 2013 Author Share Posted December 11, 2013 Jim, Awesome work on your website, thanks for sharing. Matt Quote Link to comment Share on other sites More sharing options...
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