Back to Ganoksin | FAQ | Contact

Alloying


#1

Could someone please educate me on the subject of alloying ? Or
rather alloying, ingot pouring, annealing and wire or sheet
forming ? Silver is easy. My problems begin with gold. Let me
start by what I have already done.

  1. I heat a crucible and then place my alloy( 750with 50/50 Ag
    and Cu) inside.

  2. I use a reducing flame from an oxy/hydrogen rosebud tip to
    melt the mix until it’s nice and shiny and then pour it into the
    pre-heated ingot mold (450 F ). Out comes A shiny ingot .

  3. I then tap the ingot all around to align the molecules with my
    litttle hammer.

  4. I heat the ingot just a little beyond the point of turning
    red. I think to about 1200 F and wait untill the red leaves and
    quench in de-natured alcohol.

  5. I start reducing in the mill about 50 % and then anneal as in
    step 4.

  6. I repeat step 5 and 4 and then the cracks start to appear.

  7. When I start to pull it through the drawplate the skin of the
    ingot starts to shed . I can only get 2 or 3 holes between
    anneals.

  8. My drawtongs break off the end of the wire, I go flying
    across the room and my knee hits the wall and now, 3 and a half
    hours later I have an 8 ft. length of wire, a badly wounded knee,
    a hole in the corner post of the dry-wall and a cold beer to
    nurse my wounds.

All of this to make a chain for a necklace because I have not
found any machine made chains that are worth more than their
weight in gold. And also because I am a Jeweler and not a chain
retailer- am I nuts or what?

Also, if anyone is still reading this longwinded letter, when I
am pouring alloys from the crucible into the water to make
casting grains ( shot) is their any “story” from the grains on
why they turn out other than the pretty pictures you see from
precious metals dealers. For example, the above alloy(750 Au,
50/50 Ag, Cu) when poured into the water came out long like earth
worms chopped in

three’s with the colors of copper and silver and gold all
swirling across the surfaces. Hence, do the grains tell if the
metal was too hot or not mixed properly.

Thankyou all at orchid for being so generous in any reply you
may offer to help a chained man free himself .
Peter Slone


#2

Hi Peter. I’ll ask you some more questions, if you don’t mine,
before I free you from your chains.

   1. I heat a crucible and then place my alloy( 750with 
50/50 Ag and Cu) inside. 

How clean is the metal? How did you clean it, physically or
pickling?

   2. I use a reducing flame from an oxy/hydrogen rosebud tip
to melt the mix until it's nice and shiny and then pour it into
the pre-heated ingot mold (450 F ). Out comes A  shiny ingot . 

How long did this melting take? Fast med or slow? What did the
metal look like just before you poured? Did you keep the flame
on the metal as you poured?

   3. I then tap the ingot all around to align the molecules
with my litttle hammer. 

Tap?! How about you try ‘forge’?

   4. I heat the ingot  just a little beyond the point of
turning red. I think to about 1200 F and wait untill the red
leaves and quench in de-natured alcohol. 

Beyond red? How about you try ‘before’ red?

   5. I start reducing in the mill  about 50 % and then anneal
as in step 4. 

Do you trim the ingot at all? Plus, personally I’d anneal before
50%. Say 66.66% :wink:

  6. I repeat step 5 and 4 and then the cracks start to appear.

Where do they FIRST appear?

   7. When I start to pull it through the drawplate the skin
of the ingot starts to shed . I can only get 2 or 3 holes
between anneals. 

Skin of the ‘ingot’? You mean wire or rod by now?

   8. My drawtongs break off the end of the wire, I go flying
across the room and my knee hits the wall and now, 3 and a
half hours later I have an 8 ft. length of wire, a badly
wounded knee, a hole in the corner post of the dry-wall and a
cold beer to nurse my wounds. 

Ahh, this happens to all of us :wink: Sorry.

All of this to make a chain for a necklace because I have not
found any machine made chains that are worth more than their
weight in gold. And also because I am a Jeweler and not a chain
retailer- am I nuts or what?

If you can sell your ‘manu’-factured chain and pay for your
trouble and then some, NO.

Also, if anyone is still reading this longwinded letter, when I
am pouring alloys from the crucible into the water to make
casting grains ( shot) is their any “story” from the grains
on… I’m not sure about this bit. But I can as sure as x is x
butt in with an ignorant opinion (or guess). Try pouring from a
higher height. Isn’t there some apperatus for this, like a series
of ramps alternating direction that slows the metal drops’ travel
in the water. Another thought, try hot water.

Now how about a beer?

Brian
B r i a n =A0 A d a m J e w e l l e r y E y e w e a r =A0
http://www.adam.co.nz/workshop/street.htm
http://www.adam.co.nz/workshop/bush.htm


#3

This may be a strange ? but do you stir your alloys when they
are molten? If not you might want to pick up a carbon rod to do
so


#4

Peter, Have you tried the Japanese ingot fabrication technique by
casting through water?

There was a thread on the subject a while ago.

Bill in Vista


#5

Hi Peter,

I don’t know about the other part of the alloying problems but I
do suspect thatthe shot is made by pouring the molton gold
through a mesh where it falls a goodly distance to a water
quench. While falling the metal assumes the ‘ball’ shape. This
is how shot for lead shotgun ammunition has been made for many,
many, years. I once alloyed about 1000 gm. of fine silver into
sterling. Afriend came over and brought along a titanium screen
he used in a plating bath. We poured the metal through this
screen into a 5 gallon pail of cold water and the shot we got
was just fine and quite uniform.

Regards,
Skip


#6

Dear Brian where are the numbers you are referring to? It is so
esay to make an ignot and pull it thru the rolling mill and then
thru the draw plates…How could you have so much trouble.?
Always test your end before you pull (with all you strength) in
the draw plate and it sounds like you don’t have enough end to
pull. Be sure to file the end of your gold wire at least 1/'2" so
you have enough to grip. Hope this helps and hope you got ice
on that knee right away… Just looked at your latest pages on
the net the other day… Great web site… I loved the wooden ring
set up…calgang


#7
  but I do suspect thatthe shot is made by pouring the molton
gold through a mesh where it falls a goodly distance to a water
quench.  

In industry, what’s usually used is called a shot cup. This
amounts to a crucible, the bottom of which has been drilled with
a bunch of small holes. The crucible, usually graphite, is kept
at a temp only a little below that of the pouring crucible, so
the metal isn’t chilled too much as it is seperated into the
small controlled streams by the cup. It then falls far enough
in air, as Skip suggests, to chill enough to stay uniform when it
hits the water. But there are some refinements over what you can
do in a small studio. Because the melting is generally done with
a bottom pour, induction melt setup, the pour from the melting
crucible to the shot cup is from uniformly clean metal with no
dross (comes from the bottom of the crucible, after all). the
whole pouring environment, crucible, shot cup, and air space
between the shot cup and the water tank is filled with an inert
or inert+reducing gas mix. Hydrogen plus nitrogen is a common
one. this keeps the falling and solidifying shot clean from
oxide formation as it falls. Melt temps and the temp of the
shot cup can be controlled well enough so there is good control
over the shape of the grains formed.

Also, after shotting, the finished shot is seived, so only shot
within a given size range is kept, out of size shot is repoured.
And the shot is also often put into a tumbler. No abrasive
needed, but tumbled with itself to brighten it up.

Long thin thready shot is too hot when it hits the water, and is
maybe also still in a stream, not having broken up completely
into seperate droplets. You can pour more slowly and from higher
up to get better shape. Then, pickle the shot completely to
remove some of those scaley surfaces. Might take a BRIEF nitric
dip too, if the scale is very persistant. And you too, can
tumble your shot if you’ve got a tumbler.

Peter Rowe


#8

Thank you all for your valued contributions to my education. I do
have one more question to this thread though. It is my
understanding that oxygen coming into contact with molten metal
is not good… so… when I’m pouring shot ( without
expensive oxygen absorbing gases such as argon etc. ) isn’ t
there a contradiction in pouring from a greater height ? I have
been holding the crucible about an inch from the water and
keeping the flame on the metal and pouring through the flame into
the water believing that I’m eliminating excess oxygen. Wouldn’t
pouring the metal from a height of say three feet give the metal
more opportunity to absorb oxygen ? Could pouring from such a
close distance be a reason for getting long stringy shot or have
I still overheated

the metal regardless of the height of pouring ?

        Peter Slone

#9

Hi Peter,

Most every operation we do is a trade off between several
factors. In the case of pouring molten metal into water to create
shot, you have to balance the amount of oxygen you’re willing to
let the molten metal absorb with the shape of the shot you’re
willing to accept.

If you want round shot & don’t want the cost of an oxygen free
pouring atmosphere, one way to get it is to let the molten metal
travel farther from the crucible to the water bath. This longer
path does several things.

1. It allows the molten metal to cool more before striking the water bath.
2. It allows the metal to reach an almost perfect spherical shape.
3. It allows the metal to absorb more gases (oxygen included) from the air.

There are other things that happen also, but these are the ones
that affect your situation the most.

If you want truly oxy free shot, then you have to pay the piper
& get a hi tech melting/pouring unit. However, have you proven
that producing shot with a longer path through the air produces
an inferior shot? Maybe you’re over exaggerating the oxygen
absorption condition.

Dave


#10

Peter, I did not want to make light of your alloying problems but
warm beer is a serious thing.

Have you tried the Japanese twice alloyed cast into water
technique (nothing to do with beer)? It tends to produce an
oxygen free ingot.

Envision a non-rusting tube about 3 inches high by 2 inches in
diameter. Cover one end with a triple layer of white cotton
fabric. Not too tight, actually a little dished. (My “casting
cradle” is scalloped on the bottom to allow an easy water flow
into the tube, kind of like a tripod). Envision this cradle
sitting in a larger non-rusting bucket. Hot water is added to
the bucket until the hot water is level with the cotton cloth
layers.

Get ready to go.

-Boil-up a quart of water.
-Put two beers in the fridge.
-Ask for some help, works a bit easier with another
person assisting.
-Melt up your metals, stir well, when ready to use,
ask assistant to pour the boiling water into the 
large container until the "casting cradle" is 
under one (1) inch of water.
-Pour the molten metal through the water onto
the cotton cloth.
-Wait until the noises cease.
-Retrieve the ingot.
-Drink one beer.
-Repeat all of the casting procedures and cast alloy
a second time.
-Wait until the noises cease.
-Retrieve oxygen free ingot.
-Drink second beer.

I sure like this metal working stuff.

Bill in Vista


#11
	ask assistant to pour the boiling water into the 	large
container until the "casting cradle" is 	under one (1) inch of
water. 

Hi William, Nice to hear of another doing this. I like this way
of making ingots; do it a lot. In fact I teach workshops on
alloying and I introduce this method - what I call the ‘Satsuo
Ando’ method of pouring ingots, named after the guy that
introduced it to a bunch of SNAG workshops back around 1981, I
believe. Article on it in the SNAG Goldsmith Papers of that
time. Your method is a slightly different variation on the theme
and I’m interested in all the possible variations. May I quote
you in my workshop? I’d like to discuss it further (praps
off-list). I have an idea or two to share. F’rinstance I get the
helper to drink the beer for me.

I sure like this metal working stuff. 

You’re not wrong there!

Cheers
Brian
B r i a n =A0 A d a m J e w e l l e r y E y e w e a r =A0
@Brian_Adam1 ph/fx +64 9 817 6816 NEW ZEALAND
http://www.adam.co.nz/