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Mokume gane questions


#1

Hi,

I am a newly registered user, and this is my first post. I am
looking forward to reading your contributions and leveraging the
wealth of info you have accumulated collectively.

My name is Joss Delage, I am a hobbyist knifemaker (and very junior
at that…) I have lived in Seattle for the last 3 years,
previously was in NC, and I am originally from France. I work full
time for Amazon.com as a product manager.

One of my short term goal is to produce mokume gane, to use for
knife fittings, etc. For a variety of reasons, I would like to first
become proficient with billets made of 2 or more of the following:
bronze, brass, copper, and nickel silver. I have read - with
pleasure and interest - Steve Midgett’s book, but I have a few
questions left. Most of my concerns relate to the fact that for
knifemaking, the requirements often call for larger billets than for
jewelry.

  1. I will use an electric kiln; is 1,500F the right firing
    temperature for those alloys?

  2. Is there an optimal stacking order for those copper alloys, i.e.,
    are there alloys that should or not be in contact with each others?
    Or does it not matter?

  3. Is there an optimal thickness - gauge? - for the metal sheets?

  4. Is there an optimal thickness for the stack, other than the
    necessity to exercise pressure on the entire surface? The stacks
    that are depicted in Steve’s book seem quite small for knifemaking
    applications - could they be made larger (wider & thicker)? Or
    would it be advisable to make several small billets, forge them down,
    and weld them together?

Thank you all for your help!

Sincerely,

Joss Delage


#2

Jose -

I have been making billets for about two years now using James
Binnion’s technique of kiln-fired mokume. My kiln is old and cheap
and I watch it always so that the temp. stays close to what I had
predicted. I have made copper/brass/nickel billets fired at between
1649 and 1700 degrees F for 7 hrs with leakage of brass from the
billet but otherwise good bonding.

I also fired a copper/sterling billets at between about 1300 degrees
F for another 7 hours with no leakage and good bonding, and a
bronze/copper/silver billet at about 1300 , also with good bonding.
That billet reached 1500 for several minutes with no leakage or other
apparent ill effects.

James Binnion (who is on this forum and who is exceedingly generous
with his expertise) recommended that I not place bronze (nugold) in
direct contact with silver because its zinc content , combined with
sterling makes solder. I believe this also holds for brass.

Binnion’s Mokume-Gane workshop
http://wuarchive.wustl.edu/edu/arts/metal/TOC/proces/forge/mokume01.html
recommends firing the billet at 50-100 degrees F below the lowest
melting point of metal in the stack.

In all instances, I used 3.25X2" sheets of 24ga metals and the only
limit I have for the size and number of sheets I bond is determined
by how close I can get my torque plates, their size, and the size of
my kiln. For me, there is a secondary limit on size which is imposed
by my rolling mill.

One other comment. I find that the more nickel I have in a billet,
the harder it is to work. I have one billet that is so rich in
nickel that I have to roll in tiny increments with much annealing to
get any reduction at all. It is very hard and time-consuming for me.
In contrast, substitution of sterling for nickel in the billets
makes rolling a dream. I use my mokume in jewelry where silver is
probably preferred over nickel - I don’t know if it will make a big
difference for you.

Cheers -
Debra K Hoffmaster
@Debra_Hoffmaster


#3

Hello Ross Mokume gane can be a very beautiful form of metalsmithing.
I have not done very much but i hope i can help anyway . If you find
it very frustrating to begin with you must persevere , it may take
you a year or two before you start getting good results but all the
hard work will be well worth it. You can learn some theory from a
book but trial and error will be your best teacher . The electric
furnace is a good start to get clean solder joins or bonds between
metals . I think the best thing I can say is to go buy as much metal
as you can carry and just start doing it . Even with a lot of advice
and help you will most likely still have errors as some techniques
seem to work differently for different people its a matter of using
the theory you can get from books and then finding the method that
works best for you. Start off with simple projects first and record
all the specs like temperature & method etc each time you do
something or you will make the same mistakes more than once .

http://members.home.net/moocat12/knifelink/info.htm
http://pangea.stanford.edu/~nathan/knifewish.html


http://www.mokume.com/bookvid2.html


#4
    1) I will use an electric kiln; is 1,500F the right firing
temperature for those alloys? 

I’m not an expert, but I have tried to make the laminated stock for
producing this stuff… with mixed results.

The temperature to fire it at should be a bit less than the lowest
melting point of the metals involved. The point where the metal
starts to sweat is right.

It really helps if you pick metals that have similar melting points.
For instance, do not try to laminate pure silver and palladium white
gold. :-).

    2) Is there an optimal stacking order for those copper alloys,
i.e., are there alloys that should or not be in contact with each
others? Or does it not matter? 

The problem you will encounter with the copper alloys is that the
oxygen in the furnace will react with them. If they oxidize, they
will not fuse. You have to pack the vise you’re using to compress
them with a lot of charcoal, and try to make some kind of airtight
casing around it.

The rest I don’t know. :-).

For myself, I was able to adequately fuse 24kt gold with fine
silver, and the fine silver with 18kt green gold.

I had poor results trying to fuse palladium white gold (very hard,
and high melting point), to anything, and 14kt pink gold (high copper
content) I found also to be difficult. Both of these layers
delaminated when I tried to work the stack.

This was just an experiment, and I did not go all out packing with
carbon and such.

  • darcy

#5

You mentioned reading one of Steve Midgett’s books on mokume. Are
you aware he has two? The latter book, Mokume Gane, A Comprehensive
Study, has a chart of metals compatibility. He’s done the research
and experimentation.

However, you also stated you were interested in making knives and
swords, which is a little different critter. To get billets large
enough for swords, it’s necessary to do hot forging, and that
crosses over into blacksmithing skills. You might want to try
researching Damascus or Damascene steel. You can find links to sword
and knife making guilds through the Society of Creative Anachronisms.


#6

If you Mokume fans haven’t gotten it yet, Steve Midgett’s second
book “Comprehensive Study” (as opposed to “For the Small Shop”?) has
very detailed scientific on how to determine the proper
firing temperature based on the metals used in the billet. Takes some
work, but removes the guessing. It also provides detailed information
on the compatibility of different metals in the billet, and working
resulting properties.

Jim Binnion and other pioneers also contributed valuable techniques
and insights to this book. Even if you never plan to make your own
mokume, it’s still a great book! Visually overwhelming! A "must have"
for any serious metalsmithing library! :wink:

All the best,
Dave
Dave Sebaste
Sebaste Studio and
Carolina Artisans’ Gallery
Charlotte, NC (USA)
dave@sebaste.com


#7

Thanks. I was indeed referring to Steve’s latest book, which I
agree with everyone is just amazing. And the chart was indeed very
helpful. However, in the book I couldn’t find some specific
hence my questions.

As to the knifemaking, I would only use small pieces of mokume for
insert, fittings (guards & pomels), and such. I.e., larger billets
than for most jewelry purposes, but still doable in an electric
kiln.

JD