I have a granulation problem. I made electrum (my customer wanted
white metal with yellow gold granulation). I put the granulation on,
pickled, picked, set the stone, and placed into the ultrasonic
cleaner and sent off to the customer. 5 months later it came back
for a cleaning. I put it into the ultrasonic and granulation fell
off.
Does anyone have any suggestions? Please don’t give me a hard time
about electrum you have already done that and we don’t need a repeat.
Someone mentioned granulation the other day and it reminded me of a
question/problem I have. When I’ve had a go at granulation (or
balling up wire for earrings), as the silver cools it always has a
dent in it and looks a little like the skin on a custard! What am I
doing wrong, and how can I fix this problem?
If you are using sterling silver, the copper alloy in the sterling
is melting at a different temperature, therefore, you will see the
little wrinkling effect. Varying amounts of copper in silver give you
"reticulation" silver, and the result is a great wrinkling effect.
But that is not what you are trying to achieve here.
You won’t see this in fine silver, if using the true granulation
process; same is with gold granulation.
If you place the heat directly at the bottom tip of your wire, any
dirt or grease can cause an uneven melting. I suggest to flux the
sterling wire, heat the wire up and down about the last 5mm from the
bottom and then concentrate the heat at the tip. This will give the
silver time to heat completely and your result should be a nice
rounded ball at the end. Go fast and hot to reduce the wrinkle
effect.
With fine silver, you can just heat the tip and you won’t run into
this problem.
The term “granulation” is NOT creating a rounded ball at the end of
a wire. Granulation is a delicate fusing of a sphere of metal,
usually gold or fine silver and the bonding they create. The top most
skin of the metal is what is melting and the granulation spheres
adhere to this. In gold, the spheres are coated in copper to create a
"eutectic" bonding. This alloy creates a lower melting temperature
for the spheres aiding the granules adhere to the gold, creating a
"fillet" of gold just underneath the sphere.
On making spheres, I have read a couple different methods for having
them come out round. The first is to tilt the charcoal block and
place a dish of water at the low end. This way, the spheres ball up
and roll right off. They don’t have a chance to sit and develop a
flat spot. The second is to make a small indent in the charcoal block
(like with your smallest dapping punch) so the sphere will be sitting
in an indent. Some people like the indent because it helps to keep
the granules from moving around on the sheet when trying to arrange
them in a pattern. For my purposes, I don’t want a dent either. Hope
this helps.
Helen. The dent is caused by ‘slumping’ which can be caused by a
sudden cooling of the surface of the metal. The inside is still
molten and the surface cooling caused distortion.
Try this, as you heat and the ball forms, instead of quickly
removing the flame, move it away slowly…even bring it back for a
sec or two just to keep the surface hot while the inside has a chance
to cool. That should solve the problem.
If you place the heat directly at the bottom tip of your wire, any
dirt or grease can cause an uneven melting.
I’ll try this thanks.
The term "granulation" is NOT creating a rounded ball at the end
of a wire.
Yes I know this. I was saying that I have the same problem when I do
granulation AND when I ball up a wire for making earrings. I have
done both and have the same problem but as you say it may be due to
the fact that I’m using sterling instead of fine silver. When I’ve
done granulation, it turns out ok if I can position the “dent”
underneath but sometimes the little devils move while heat is being
applied. I’ll use fine silver for doing granulation next time.
An easy way to produce a quantity of granules of the precisely the
same size is to make jump rings and melt them into balls. In order to
exactly reproduce what you’ve done, keep a record of the wire gauge,
winding mandrel size and resulting granule diameter.
Try this, as you heat and the ball forms, instead of quickly
removing the flame, move it away slowly...even bring it back for a
sec or two just to keep the surface hot while the inside has a
chance to cool. That should solve the problem.
Ah I feel some experiment coming on. I’ve just been advised by Kim
that rapid cooling in water makes for a round sphere but this advice
seems to be the opposite. I think I’ll have to try both methods and
see which one works.
The dent is caused by 'slumping' which can be caused by a sudden
cooling of the surface of the metal. The inside is still molten and
the surface cooling caused distortion.
Try this, as you heat and the ball forms, instead of quickly removing
the flame, move it away slowly…even bring it back for a sec or two
just to keep the surface hot while the inside has a chance to cool.
That should solve the problem.
You could also aquire graphite boards and place small drilled dimples
in them. Put your torch to it with your cut pieces of metal in the
dimples. For consistent size and large quantities of granulation
beads
I would recommend buying them pre-made.
If you want to save a little money and do it yourself I would highly
recommend getting pre cut lengths of wire. You would haft to measure
the gauge and length of the cut so as to match what you make by hand.
Lots of people offer the pre-made beads but we make cut to size wire
and solder.
I also notice people who put there torch to one side of wire when
making headpins and the like. Sometimes it works but mostly the ball
is off to one side and not even on the wire. Try heating from
directly below the wire to get even heat distribution.