ok, since you asked, here’s my method for making Mokume, it’s far
from perfected as I’ve only done it a few times. I use an Aim bead
annealing kiln, they’re about $400 from a glass blowing supply store
(try www.waleapparatus.com ).
First thing I do is get my metal. I use Sterling and copper between
30 and 16 ga. Cut them down to approx 1" x 3", clap them together and
file the edges so they all line up perfectly. This is very important
later on when rolling to avoid separation. once that’s done I undo
the clamp, then sand each sheet on both sides with a 200 or so grit
emery paper, then take it down a little more with 600 grit. I finish
the sheets off with a soak in an ultrasonic cleaner, then alchahol as
a final cleaner. This may seem like I’m over doing it, but I haven’t
had any problems since my first stack (It didn’t bond well, and
wasn’t cleaned as well).
Next I get my torque plates ready. These are 6"x6"x1.25" mild steel
plates with 1/2" holes drilled about an inch in from each corner.
I’ve used thinner steel, it eventually warps. I had the steel
already, so I just made it myself. Your best bet however is to
contact a welding or machine shop in your area. I have no idea what 2
plates will cost, but I think I used about $20 or so worth of steel,
and I was getting it at a wholesale rate. Anyways. Take the two
plates, make sure they are clean and perfectly smooth on the inside.
Coat the plates with yellow ochre, and carefully place your stack of
precious metals between the two plates. No flux is used, it’s just
bare metal on bare metal, and VERY clean.
Next step is tightening it all down. For this I start in a vise,
clamp it all together, make sure the stack is still well aligned. if
not, readjust. I then put 4 bolts, with washers on both sides of the
bundle. tighten up the bolt equally, a torque wrench is best for
this. get it as tight as you can by hand, don’t bother with over
tightening it as this will only snap your bolts off.
Then I put the whole device into a small metal box I made with some
heavy (around 16 ga) sheet metal, made to be about an inch bigger in
all dimensions than my loaded press. I fill the box up with pellets
of bone charcoal, but any form of charcoal should do, to reduce
oxygen. I also lined the floor of my kiln with charcoal, and pile in
a few very well burned chunks of wood I have for this purpose. The
idea is to reduce the open space in my kiln as much as possible with
material that will create a reduction environment. I have been
thinking of a way to use argon to flood the kiln, but not sure yet if
I can seal the kiln well enough.
Once the press is in the kiln I close it up and set the kiln to go
up to 1500F degrees and let it sit for 4-5 hours. I basically just do
something else. This is where the magic of diffusion takes place.
Under the very high temperatures the steel expand with the copper and
silver to create pressure that you just can’t make any other way.
This process allows the silver and copper molecules to migrate into
one another, and forms a solid billet. When I’m ready to take the
metal out I turn up the kiln a bit to 1550 for about 5 minutes, I’ve
found this added little burst at the end actually can make a
difference.
Using tongs I pull the box from the kiln and dump out the press on
my studio floor (it’s a messy process). I grab the press (still red
hot) with the tong and place it on an anvil. I strike it several
times with a firm, but medium hard blow on the top, turn it over and
do it again. At this point I use bolt cutters to go in between the
plates and cut each bolt quickly. I remove the billet (still almost
red hot, too hot for gloves) and proceed to, for lack of a better
term, forge the hell out of it. I generally work them until my arm is
sore, and they’re cool enough to pick up bare handed. I’m not trying
to flatten the billet, just “feeling” it, letting it know that it’s
only just begun.
From this point you can treat it like any other ingot or billet.
Mine tend to be about 1/4" or so thick, which I will forge and roll
out to 16ga and use in the next billet to build up layers. I’ve only
done this Mokume thing about 5 times now, so my process is far from
perfected, but it’s at a point now where it’s basically without major
flaw. So far I have only made 1 billet from previously laminated
metals for 30 layers of silver and copper total. (5 16ga sheets of
alternating silver/copper in 6 layers)
Anyways, that’s my process, as for what I do with the metal, well…
I store it for the moment, but I’ll get around to working more of it
soon So far I have made a couple really nice emerald rings, but
that’s about it. If you have any more questions, or need more
specific info, let me know, I’m sure I missed something, it’s late, I
need sleep, it’s final week, my life is stressed =) And please let me
know how it comes out. I truly believe the only way to success with
mokume is to just really get into it, and do it. Make sure you take
care of the metal before you press it, and afterward pour all your
energy into forging it. Nothing in my life right now feels better
than pounding away my frustration and anger and fears into the
metal, and it’s what I think makes the difference. Don’t give up, my
first stack sucked, delaminated the day after I rolled it, I almost
gave up, thinking my equipment couldn’t handle it. Glad I decided to
give it another go. ok, time for sleep, good luck
-Doug