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View Full Version : Mokume Gane sheet ...hmmm



Chris Moody
26-10-2014, 10:14 AM
First off, I'm an amateur hobbyist, so maybe I am just being an idiot, or naive, hopefully I can be enlightened?

I have always been in love with Damascus steel and similar materials, with organic textures, and thought I'd look in to Cooksons Mokume Gane sheet as a test, as we are looking to have Mokume Gane wedding rings next year.

The first point is that the description on Cooksons website is a bit minimal. There is no mention of what metals are used in the production of the Mokume, leaving the customer to have to make assumptions...I assume it's silver and copper, but for all I know I could be wrong. I emailed Cooksons a few weeks ago asking what it was, and still don't have a reply.

The next point is that the Mokume is listed as in stock, but when ordered I had a 2 week wait till shipment? I assume then it's not in stock, but made to order?

The final point is that I feel the product is pretty poor. What I received looks like it's simply silver sheet that has had copper colouring stamped on top of it (the pattern does not go all the way through the metal, and I imagine a light polishing will remove the copper pattern completely!?) If this is the case shouldn't the description/title of the product reflect this, and be "Mokume gane patterned (silver) sheet" or similar, as if I am correct in my evaluation it's not really the standard, folded in mix of alloys you'd expect from Mokume Gane?

Pickle
26-10-2014, 10:39 AM
Hi Chris,

I fell heir to some small silver and copper mokume gane offcuts. I must say they do not look very impressive as they are but I was lead to believe that the trick is all in the finishing. I have also been told that perhaps using some copper etching solution would add texture and interest. I can't wait to hear any replies to your post so that I can crack on and incorporate the offcuts into some designs :)

ps_bond
26-10-2014, 10:48 AM
I've been working down some billets recently, and I intend to clean & fire another billet of non-precious mokume later today.

Why do you feel the sheet is just patterned on the surface? I've never seen the commercial stuff, so can't really comment. But since half the fun is the patterning it has limited interest to me.

As for wedding rings - I can help if you need. Just don't use a copper alloy in the mix!

Finishing mokume is always fun. A highly reflective surface makes it much more difficult to see the pattern; there's a few ways round this, including scratch brushing, sandblasting, patination (including heat patina if you're gentle with the torch).

Chris Moody
26-10-2014, 02:45 PM
I've taken some photos of the strip I have that hopefully show why I am wondering if it is just printed.

Here you can see how the copper pattern doesn't go all the way through the metal, it appears to end halfway down on side? The other side (image 3) doesn't seem to have ANY copper in it? I should have put a ruler in the photos for scale really. As the strip is so thin, even though it looks like the copper goes quite far down the side, it's likely only about 0.2mm, which I'd imagine would be about right in terms of having something stamped on it?
https://farm4.staticflickr.com/3932/15446411329_9ae99f3b5f_n.jpg (https://flic.kr/p/pwWTWH)1 (https://flic.kr/p/pwWTWH) by Chris_Moody (https://www.flickr.com/people/11266603@N04/), on Flickr

This is the top pattern. I think the lighting has been quite generous in terms of how much contrast there is in the metal. To the naked eye it's a lot more faded. This in itself isn't the problem though.
https://farm4.staticflickr.com/3937/15609344806_33dcd9463f_n.jpg (https://flic.kr/p/pMkYoA)2 (https://flic.kr/p/pMkYoA) by Chris_Moody (https://www.flickr.com/people/11266603@N04/), on Flickr

Here is the other side, looking to just be solid silver?
https://farm4.staticflickr.com/3933/15447073477_94f28f9c4d_n.jpg (https://flic.kr/p/px1hM4)3 (https://flic.kr/p/px1hM4) by Chris_Moody (https://www.flickr.com/people/11266603@N04/), on Flickr

And here is the base of the strip.
https://farm6.staticflickr.com/5602/15633892712_25e75f40a0_n.jpg (https://flic.kr/p/pPvMCm)4 (https://flic.kr/p/pPvMCm) by Chris_Moody (https://www.flickr.com/people/11266603@N04/), on Flickr

Am I wrong when I was assuming that the copper should be continuous throughout the metal strip? Is there a genuine reason how/why two metals folded together would result in only one metal being visible from 2 sides?

Chris Moody
26-10-2014, 02:47 PM
Finishing mokume is always fun. A highly reflective surface makes it much more difficult to see the pattern; there's a few ways round this, including scratch brushing, sandblasting, patination (including heat patina if you're gentle with the torch).

The copper pattern looks so thin that I wonder if I tried anything whether it would just wear off straight away though ;)

ps_bond
26-10-2014, 03:25 PM
I wonder if this helps: In patterning mokume, you have a liquorice allsort assembly of metals; you generally carve into only the first few layers (or raise the sheet with punches & file it smooth). You then flatten the material so you have a set of contour lines showing where you cut metal away. If you carve too deeply, you have to roll or forge the laminate down more to flatten it. If you want a pattern all the way through, you have Swiss cheese... It's not like many of the pattern-welded steels where you have no material loss.

(Twisted mokume gives the same star pattern as you get with pattern welded steel, of course - but you still have to cut the twist lengthways)

A lot of traditional Japanese mokume gane has the lower 3rd as solid copper, which is sensible in many ways. Why put the work in when it contributes nothing to the final effect?

Even if you sand the surface down a bit, you'll just change the pattern slightly.

medusa
26-10-2014, 04:05 PM
As for wedding rings - I can help if you need. Just don't use a copper alloy in the mix!



if it's only on the outside, say laminated on and not in constant contact with skin, would it still get etched then?

ps_bond
26-10-2014, 04:17 PM
If it's a ring, it'll be in contact with the fingers either side. Well, for a finger ring anyway. I've made some earrings that are lenticular; silver at the back, Cu/Ag at the front so they shouldn't be in contact. Pendants similarly. It needs liquid to create the battery so that the copper sacrificially corrodes.

Just put my billet in to bake @ 850C for 10 hours; the new press has had its first real work - previously I could only hit 8T, the 20T compression should help the stack along. Changed my cleaning methods slightly too, so it'll be interesting to see if the speedier approach works as well as I think it should.

Chris Moody
26-10-2014, 04:36 PM
I wonder if this helps: In patterning mokume, you have a liquorice allsort assembly of metals; you generally carve into only the first few layers (or raise the sheet with punches & file it smooth). You then flatten the material so you have a set of contour lines showing where you cut metal away. If you carve too deeply, you have to roll or forge the laminate down more to flatten it. If you want a pattern all the way through, you have Swiss cheese... It's not like many of the pattern-welded steels where you have no material loss.

(Twisted mokume gives the same star pattern as you get with pattern welded steel, of course - but you still have to cut the twist lengthways)

A lot of traditional Japanese mokume gane has the lower 3rd as solid copper, which is sensible in many ways. Why put the work in when it contributes nothing to the final effect?

Even if you sand the surface down a bit, you'll just change the pattern slightly.

So it was me being a numpty then? I had assumed the process was a case of folding thin sheets of one metal, over sheets/pieces of another metal, and then pressing them under heat, and then repeating this process several times. Then the end product is cut or milled into pieces where the cross sections show the different metals all the way through!

ps_bond
26-10-2014, 04:42 PM
Stack them and fire them, you can repeat it but you need to make sure you're always trying to fuse dissimilar metals at the interface. You can do pattern welded by (electric) welding the ends and forge welding the stack too. 9 times out of 10 it's more time efficient than the traditional fold & weld, depends what you're trying to achieve.

As an aside, if you want to see some *really* good pattern welded steel, look at Mick Maxen's work.