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Smooth surface granules


#1

I’ve been experimenting for granulation by using copper oxide on
sterling silver and I can fuse them each other.

but I need to make spheres surface smooth rounded one like pearl.
now my result has well-creased/get wrinkled on spheres.did I heated
them up too much??

also I want to make much more perfect circle spheres and how can I
make thema lot as much as efficiently. I tried slopewise
charcoal-block procedure put water bowl alongside. some of the
spheres smash up on impact onto water. falling distance was 2-3cm.

does anyone know solution?
Mike


#2
also I want to make much more perfect circle spheres and how can I
make thema lot as much as efficiently. I tried slopewise
charcoal-block procedure put water bowl alongside. some of the
spheres smash up on impact onto water. falling distance was 2-3cm. 

Make imperfect spheres as many as you need. Then prepare a box with
lid, made out of sheet iron or steel. Box like they sell candies
would work. Put a layer of powered charcoal on the bottom, distribute
your spheres, powered charcoal on top, and repeat until box is
completely filled. Close the lid and bring the box to bright red
heat. If you have an oven, it is the best. That should do it.

Leonid Surpin
www.studioarete.com


#3

It’s actually very easy to make perfectly spherical balls all the
same size.

Make up jump rings in fine silver (or gold) and sprinkle them into a
crucible in layers with powdered charcoal. I use ground up drawing
charcoal. Make sure that the rings do not touch each other. Put a
much thicker layer of charcoal on the top, place it in a kiln and
take the temperature up to and above the melting point of the metal.
Hold it for at least 15 minutes.

Allow it to cool in the kiln, or if you prefer, remove it gently and
let it come down below the melting point. Pour the whole thing into
a bucket of water and rinse away the charcoal. If some of the rings
were touching you will have a mixture of larger and smaller balls.
Sort these out by hand or with a diamond sieve.


#4

Thank you for eonid and Tony’s quick and kind response.I’m quite
glad about that.

actually I have tried to produce bunch of spheres in “crucible in
layers with powdered charcoal” way. I made easy-build kiln by fire
bricks then put the crucible with lid into the kiln. I only have
normal air pomp torch (not oxygen torch). so I tried heat the kiln
up by double torches from either side of holes on bricks. put a small
copper piece in the kiln to check for the temperature and recognized
the copper melts. keep 2 torches fire during 20mins but silver
pieces didnt melt to spheres shapes yet…(I tried 3 times this way)
I have electronic kiln for glass as well can rise it temperature
until around 2000F/1093C, but it didnt work for making spheres in
crucibles because temperature is not enough for silvers in crucible
filled with charcoal powder.

is this solution to buy “oxygen torch”?

thank you,
Mike


#5

Hello,

A Question Re: the charcoal… does it need to be powdered charcoal?
There is a granular charcoal being sold for use with the new base
metal clays and for PMCPro. Would this type of charcoal be suitable
for refining fine silver or gold granules?

Thanks,
Linda Kaye-Moses


#6
but it didnt work for making spheres in crucibles because
temperature is not enough for silvers in crucible filled with
charcoal powder. 

Try with small iron box. It requires less temperature.

Leonid Surpin
www.studioarete.com


#7

If you can’t reach the required temperature, despite your kiln
reaching the melting point of silver, maybe using a much smaller
crucible would work.

Tony Konrath


#8
There is a granular charcoal being sold for use with the new base
metal clays and for PMCPro. Would this type of charcoal be
suitable for refining fine silver or gold granules? 

To answer it properly we have to understand what is involved in
formation of perfect granules.

Any natural process always conform itself to function with the least
amount of energy involved. For instance - water naturally flows
downward, but has to be pumped to flow upwards, and etc… Spherical
shape is the most energy efficient configuration in nature. That is
why whenever possible, substances try to form a sphere. That is the
reason behind such phenomena as surface tension.

To form a perfect granules, we must provide excess of energy (
temperature ), and after granules are formed, the environment must be
conducive to maintaining their shapes. That is why we surround them
with charcoal powder. The finer the power the more perfect the shape
will be. There must be no packing of powder, just sifting.

The idea is to allow granule to form into sphere. When this happens,
granule will sink into the powder, due to shifting of center of
gravity. Powder under the granule will be displaced. Newly formed
space, above the granule, will be filled. This process will create
and envelope around granules and allow them to solidify into perfect
shape. But this puts a number of requirements on charcoal powder. It
must be very, very finely crushed and sifted. The process is only
possible when particles are tiny and uniform, so they can flow past
each other like a liquid.

Leonid Surpin
www.studioarete.com


#9
A Question Re: the charcoal... does it need to be powdered
charcoal? There is a granular charcoal being sold for use with the
new base metal clays and for PMCPro. Would this type of charcoal be
suitable for refining fine silver or gold granules? 

I think it would be OK but it needs to be a powder (not too fine)
rather than a granule, so put it through a coffee grinder or a
pestle and mortar.

The powder supports the silver and I’m afraid that a granule would
just let it all slip to the bottom and form a lump.


#10
Try with small iron box. It requires less temperature. 

Leonid’s idea has great merit. One of the tins that cough drops come
in should work - make sure it’s iron rather than aluminum by testing
it with a magnet.

Tony Konrath


#11

Thank you for the very helpful answer by Leonid and Tony. I’m
grateful.

I experimented to use small stainless steel cup (diameter: 2inch,
hight: 1.25 inch) for making many granulation yesterday. I should use
iron box but has not found out proper one yet.

implements are 2 gas torches, handmade kiln by several firebrick put
stainless steel cup with lid in kiln and heating it up during
20minutes. the result was half of amount could be sphere shape, half
of the rest as they were. i got many elliptic pieces just melted the
end of sliver chips.

obviously heating was not enough yet from the result. I should try
again using iron box is better heat conductivity than stainless
steel.

could you tell me your circumstance of making granules in kiln as
for my reference? my easy handmade firebrick kiln has box-shaped
inside.should i make it tube-shaped inside for iron box being
surrounded by fire?

thank you,
Mike


#12
could you tell me your circumstance of making granules in kiln as
for my reference? my easy handmade firebrick kiln has box-shaped
inside.should i make it tube-shaped inside for iron box being
surrounded by fire? 

Round one is definitely better, but even with square one you should
be able to do it. I am puzzled.

Leonid Surpin
www.studioarete.com


#13

good morning Mike,

Since many years I know* an italian goldsmith from Todi, Mr.
Giovanni CORVAJA. Giovanni has true master skills in various
metalsmith technologies. He holds workshops on jewelry making
technologies. You may want to take a look at his website at

http://web.me.com/giovanni.corvaja/giovanni.corvaja/Granulation.html
or
http://web.me.com/giovanni.corvaja/giovanni.corvaja/Welcome.html

Best regards and wishing you and Orchid a happy New Year

Ernest

  • Since about ten years Giovanni is using some of our industrial
    flame generators for precision wire work with gold & platinum alloys.

Spirig Ernest,
spirig.com