Granulation
By Ed Colbeth
Email: @Ed_Colbeth
The application of grans onto a surface using fusion.
We have to fuse the grans because the point of contact is so small
that the solder fillets would have to be almost microscopic, and it
would drive us insane trying to get the solder in the right place
at the right time. So the result is more beautiful if we fuse. This
does create some problems. The temperature that the metal fuses at
is just below the melting temperature. Carbon created by the
oxidation of the hide glue remains on the surface between the grans
and the base. This carbon creates an area with a slightly lower
melting temperature than the metal itself. Any bezel’s or borders
must be fused as well, before the granulation is fused.
Supplies and Equipment
Granulation kiln
Charcoal block
Fine silver wire 26ga, sheet 26ga
00 brush
Hide glue
Battern’s flux
white out
Fine nose tweezers
Glass pie plate
Acetylene torch
Process
Making Grans:
There are many methods for making granules, But the following
method will create the most uniform grans.
Step 1. Draw down fine silver wire to 26 and 30 gauge.
Step 2. Using a small paperclip as a mandrel, make lots of small
jump rings.
Step 3. Put charcoal block onto on a small fire brick inside and
then into a glass pie plate, put about 1/4" of water in plate.
Step 4. Spread the jump rings out evenly on the charcoal block,
spaced about 1/4 " apart, and heat until they turn into little
spheres or grans.
Step 5. Tilt up the block and the grans will run off, Repeat until
the desired number of grans have been made.
Surface Preparation
If you want to work with a domed or 3-d surface fashion it from
the sheet of fine silver, don’t make it to big or you will be
applying grans forever.
Step 1. Die-form or dome sheet.
Step 2. Polish metal now as you will not be able to after
granulation.
Step 3. Apply border wire around the outside, this is both
decorative and functional. The border keeps the grans from rolling
off of the piece and accents all the little spheres.
Step 4. Also if you want to mount a stone the attached the bezel
now.
Both the bezel and the border need to be fused. First fuse the
wire together and then fuse it to the surface. This process is very
similar to soldering, apply glue(see below) mixture to contact
points heat until contact points flash, that’s it, no cleanup! Just
don’t overheat.
Applying the Grans
Step 1. Paint the bottom of the piece with white out to help
prevent overheating.
Step 2. Using the following formula make your glue: 2 drops hide
glue, 2 drops flux, 12 drops distilled water.
Step 3. Apply grans by dipping brush in glue mixture and then
picking up a gran and putting it in place according to your design.
After the grans are in place if you need to move them around
moisten the brush with water, as you do not want to use too much
glue.
Step 4. Let dry on top of kiln, and then put the piece onto the
preheated kiln and cover until it glows a bright red.
Step 5. Put a small tip on your torch and set the regulator for a
reducing flame. Move the flame across the surface never stopping.
Watch for the space between the gran and the sheet to flash, this
happens very fast and if you heat the piece for � a second to long
it will turn into a puddle. Once the all the grans have flashed
your done, air cool the piece and finish.
Finishing
After fusion the piece can be soldered, to add a back, pin back or
bail, etc. Be careful not to scratch the finished surface or to
handle it roughly. It is best to cut things to the exact size and
solder precisely, with no clean up necessary. Be careful when
pickling, place the piece in the pickle, don’t drop it in.