First a few points: I am not an expert, but have been successful
with my granulation, enough so that it is acceptable and sellable in
my galleries. Next, years ago, I took a seminar with Kent Raible,
very helpful and informative and I would recommend tht if you have
the opportunity…
Now: I use gum tragacanth powder mixed in distilled water. Kent
suggests that you add water untill the jelly-like mass dissolves.
Let sit over night until all clumps disolve. The mixture will be
milky. THEN: to 1 part gum solution, add 1 part battern’s flux and 3
parts distilled water. I coat my 18k piece with this solution, then
pick up the granules (18k) with a fine tipped brush dipped in the
solution and place them on the piece. Let them dry.
Once dry, I use a second solution (again from Kent). Add small amount
of copper carbonate powder to the above solution until you get a
creamy consistency. Then, take my small brush and dip in creamy,
green solution and lightly dab the tops of my granules until they
suck up the solution. All shuld be nicely coated, but not thick and
gummy.
Let dry.
The Hard part: I use oxy/propane torch with a reducing flame to fuse
the pieces together. I heat the brick well before fusing the piece,
so that it all heats evenly and you don’t have granular meltdown.
Heating sequence: piece turns black, black disappears, gold turns
yellow, metal turns dull red, metal turns orange red, then FLASHES.
That’s it, another second and meltdown. Once you see the flash you
are done. Kent then reduces the flame rapidly (get rid of oxygen),
keeping it on the piece and quenches it in water, this keeps the
pretty shine. I try, but not that coordinated. Pickle quickly,
lightly, 18k turns greenish in too much pickle.
I work in 18k from David Fell, Kent makes his own alloy. His
suggestion for silver is: to use 835 silver for the granules and 925
silver for the backing–do not use the copper carbonate. I have not
done this, do not know.
Good luck, any other e? please let me know.
Also, good table in Oppi Untrachts’s book on different granulation
techniques, and the Metals Technic Book by Tim McCreight has article
on silver granulation by John Cogswell. I highly recomment Tim’s
book, all the articles are wonderful, wll worth the investment.
Elizabeth