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Copper carbonate for granulation


#1

Dear Orchidians, I am just returning to gold granulation after a
lapse of many years and have read of the use of copper carbonate as
an additive to the hide glue, distilled water and flux mix. The
problem is that I can’t find any formulas to tell me how much copper
carbonate to add to this mixture. Anyone out ther e know and would
care to share? I would be very grateful for any help. Thanks so much!
all the best from finally Spring-like Long Island! Mark SannE9 AurE9a
Jewels aureajewels@aol.com 16 Mcguirk St. East Hampton, NY, 11937


#2

Jean Stark’s recipe is 1 drop hide glue, 2 drops of liquid flux and
12 drops of water. The mixture should be made fresh daily.


#3
Dear Orchidians, I am just returning to gold granulation after a
lapse of many years and have read of the use of copper carbonate
as an additive to the hide glue, distilled water and flux mix. The
problem is that I can't find any formulas to tell me how much
copper carbonate to add to this mixture. Anyone out ther e know and
would care to share? I would be very grateful for any help. Thanks
so much! all the best from finally Spring-like Long Island! Mark
SannE9 AurE9a Jewels aureajewels@aol.com 16 Mcguirk St. East
Hampton, NY, 11937 

I tried out granulation on reticulation silver - I was experimenting.
I took a good amount (soup bowl) of ammonia and dropped copper in it
(use a lid). After a couple of hours the ammonia will turn into a
deep blue color. Since I was not in a hurry, I dropped more copper in
it, (I have no idea about the saturation point). I made my ring from
the sheet of reticulated silver, soldered it with hard solder, then
took a texturing wheel and textured where I wanted the granules to
be. To make the granules, I used a bur to make holes in a charcoal
block and made jump rings of several sizes so has to have ‘big’ as
well as tiny granules. I tried it out with the big granules first. I
mixed the blue ammonia with gum arabic till the consistency was like
handy flux (very pasty-like), cleaned my ring with alcohol, 'painted’
the substance to the ring (with a toothpick) and put the granules on
the ring. After drying, I heated the ring from the inside, using the
hottest flame I could get (heating the whole construction very
rapidly - it takes something like 15 seconds). When the ring turned
red (just two fractions more than dull red), I took the flame away
and, not sure of the result, went over the granules a couple of times
(very quickly, with a reducing flame). I pickled in Sparex.
Technically, the result was very good, but after that, when I tried
to do exactly the same, but this time with big as well as tiny
granules, everything went wrong a couple of times. I guess it is a
question of experience. Also, it is strange that I can make
granulation but that I cannot fuse gold snippets to a silver shank:
everything on the surface melted and now I have a nice silver ring
with gold tears (sigh). Best, Will


#4

Mark – This may or may not be useful, in that I use copper
hydroxide rather than copper carbonate, but I have used the following
combinations:

a) Glue Solution: 10 parts distilled water to 1 part glue
b) for silver: 1 part copper to 5 parts glue solution + some drops
flux
c) for gold: 1 part copper to 4 parts glue solution

Laura.
StoneHouse Studio


#5

I am really surprised with all you artisans out there that no one
has discussed ancient methods of doing granulation. I am only going
into this for the sake of controversy and fun. It has been shown
likely that early granulators (Etruscans), used some pretty ingenious
methods of achieving what they are famous for.

FYI: Malachite occurs when carbonated water interacts with copper
minerals, or when a solution of copper interacts with limestone.

I copied this from a website:
http://www.jewelry-time.com/Archive/ANTIQUE/granulation.htm

  1. Probable technique: In the early 20th century, jewelers
    determined the ancients probably used a technique known as colloidal
    (non-metallic) hard soldering or fusion welding. Essentially, the
    process involves mixing an organic glue (perhaps fish paste or
    cowhide glue &endash; both known to the ancients) with a powdered
    copper mineral (possibly malachite) and using it to fix grains of
    gold in place on the gold sheet. When the prepared piece is heated in
    a reducing atmosphere (where there is little or no oxygen present), a
    chemical change occurs between the glue and the copper oxide. The
    nonmetallic elements combine and dissipate, leaving behind pure
    metallic copper that forms a bond at the point of contact between the
    grain and the gold substrate. It’s interesting to note the ancient
    Greek word for malachite was “chrysakolla,” which translates
    literally to “gold glue” or “gold solder.”

I wrote this myself: The chemical change that occurs between the
"glue" and the copper oxide is that the glue burns and turns to
carbon. Carbon reduces (scavenges the oxygen in the CuO2), the
copper oxide back into metallic copper.

  1. I think that another likely scenario is that malachite was
    crushed into a fine powder and added into a heated acidic bath.
    Maybe orange juice (citric acid), who knows. The copper from the
    crushed malachite went into solution with the acid. The beads or the
    substrate to be granulated or possibly both were submersed into the
    bath. Some form of iron was introduced to cause the ion exchange of
    the iron into solution and the copper out of solution. This
    displaced copper plated onto the gold items in the bath. Many of you
    have discussed this phenomena in another string that discussed
    pickling solutions. The Etruscans could then have used things like
    horse saliva, sugar, or any other sticky organic substance that
    could adhere the parts together in the pattern that they wanted. The
    copper and gold form a eutectic (lowest melting temperature alloy),
    with the gold at the points of contact that had the “glue” present.
    The copper that was on the gold parts that had not been exposed to
    the organic glue became an oxide during heating and did not form a
    eutectic with the gold. The eutectic that formed between the gold
    parts would then be less reactive than the copper oxide everywhere
    else. These parts then could be placed back into an acidic bath
    where the oxide would be removed (pickled), but the bond between the
    parts would remain.

Any other ideas?

Just for fun,
J. Tyler Teague
JETT Research
(Jewelry, Engineering, Training, and Technology)


#6
    but that I cannot fuse gold snippets to a silver shank:
everything on the surface melted and now I have a nice silver ring
with gold tears (sigh). 

Dear Will, The procedure that I use to fuse gold snippets to a SS
shank is as follows:

  1. I generally use an 18K gold for this. Seems to work better than
    lower karat.

  2. Use a flux that will not break down with prolonged heating. I use
    "Black Flux" obtained from welding supplier

  3. The trick here is to use torch control. You want to take
    advantage of the different properties of the two alloys as to how
    each handles heat conduction. Therefore you must gradually build up
    heat to the piece and let the silver give up some of it’s heat be
    wafting the flame off and on. This will allow the gold to retain
    it’s temperture while the silver dissipates some of it’s heat. (Use
    a steel mesh as an heat sink) Use a rather soft flame for better
    control.

  4. The gold will get closer to it’s melting point without the silver
    melting and you should begin to have success with this technique as
    with granulation.

Good luck
Joe Dule