We tried fine and 950 silver with different coppersalt
solutions, but the grains would never fuse without the complete
piece being melted.
Fine silver has a higher melting point than an alloy. Stick with
fine, and you’ll have fewer problems with slumping. Silver on silver
granulation is the most difficult because of the small temperature
difference between fusing and meltdown, and once you are master of
that, you are master of all granulation with few caveats. Prepolish
the base, because it will be difficult to polish out scratches
afterwards without flatspotting the granules.
The aim of the workpiece is to cover triangular flat surfaces
with beads around 0,5 mm diameter, but also larger beads stacked
to form small piramids.
I’ve never tried doing a pyramid, so I can’t advise you on this
secondly, which would be the most appropriate mixture to bond
and melt the granules together.
The bonding mixture I use is 2 drops hide glue, 4 drops Battern’s,
and 10 drops distilled water (ratio 1:2:5). This mixture only has a
life span of about 6 hours before it starts breaking down. For silver
on silver, I do not coat the granules with any copper salts, nor do I
use any copper salts in the glue mixture. The reason is, although it
does lower the fusing temperature, it alloys with the surface, and
makes successive fusing difficult, if not impossible, without
slumping the granules. Make sure you dry the glue by sitting it on a
warm surface until the glue turns black. This prevents the glue from
"working" and bubbling, and disturbing your pattern. I turn up a
corner of the base piece to facilitate picking the assemblage and
A small trinket kiln will make it easier to bring the piece up to
fusing heat across the piece, and a quick blast with the torch tip
from the top makes it fuse together. If you don’t have a trinket
kiln, use a reflective surface, like clean fire brick, and preheat
the surface around the piece first, so the heat will radiate to the
underside of the base, then work on the top. When you see the
"flash", BLOW! When I granulate, I switch to a Prestolite or a
propane torch (yeah, like the ones you get in the hardware store for
$10), because it seems to do better being bathed in a large flame
than a small flame from my Li’l Torch. The exception is when I’m
doing a scattering of granules across a surface, and in that case, I
like the pinpoint accuracy of the Li’l Torch.
Your ideal granulation has a small bond at the bottom of each
granule attaching it to the base, and to the side of each granule
where they touch one another. Your granulation should withstand
pickle, brass brushing and ultrasonic without any granules falling
off. If they do fall off, your fusing isn’t complete.
When doing a grouping, or using a mixture of small and large
granules, concentrate your heat in the densest area first. In a
triangular grouping, that will in the center of the triangle. If it
is a triangle where you have the larger granules at the base and the
smaller granules at the apex, then your flame will be concentrated
more at the base.
Another thing that helps you to be successful is to use a base sheet
that is relatively thin. I rarely use anything heavier than 22 ga.
Your granulated assemblage can be sweat soldered to a heavier piece.
The reason is, that especially for intricate and dense granulation,
your base, if too thick, can retain and radiate more heat than what
can be dissipated from that puff of your breath, and you have
slumping or meltdown. If you only have a few scatterings of granules,
say across a reticulated surface, then thickness of the base is not
as much of a problem, because the granules will not trap heat as a
densely packed area will.
You might find it beneficial to practice with some scraps and just
making some simple patterns that will be no big loss if you have a
meltdown. If you’re successful, then you have little components for
the earring posts to be attached to, or decorative components for
another piece. 98% of your time in granulation is making the granules
and making the patterns. 1% is spent fusing, and 1% is spent
polishing, soldering on additional components and adding the stones.
Nancy covered many other important points in her posting, and
perhaps between the two of us you’ll find the perfect solution.