United
Precious Metal Refining, Inc.
Ag Casting Grain Type "22"
Covered under one or more of the following #'s. U.S. Patent #
4,973,446, # 5,039,479
Sterling Silver "22" is a proprietary deoxidized sterling silver
designed to maintain maximum hardness while reducing fire scale and
porosity. Sterling "22" maximizes hardness, color and reusability.
By applying the "Know How" that has granted us two U.S. Patents, we
have developed a sterling silver with 90% of standard hardness,
while retaining many of the characteristics of our other sterling
silver grains.
Melting: Traditional methods of melting regular sterling silver
I.E. (as cool as possible) will cause a variety of problems. Most
failures with these sterling products are caused by too low of a
melt temperature. Customers familiar with silicon deoxidized gold
casting alloys should have less trouble adjusting to the appearance
of these silvers.
MELTING
Temperature Range 990° - 1020° C.
1815° - 1870° F.
REMELTING
We recommend a 50% fresh mix. Our sterling silver replenisher can
also be used without adding fresh.
FLUXING
It may be necessary to flux these silver melts. We recommend Borax,
Boric Acid or a 50/50 mixture. Do not use Carbon Containing Fluxes
or Charcoal. Skim any surface oxides off the surface before
stirring.
QUENCH TIME
15 - 20 minutes.
HARDNESS AND HEAT TREATMENT
This silver as cast will have 90% of the hardness of traditional
sterling silver. It can be hardened further by heat treatment at
300°C / 575° F for 1 hour, and air cool.
INVESTMENT REMOVAL
Most standard investment removers will successfully remove the
investment powder. The best solutions are the sulfuric and
hydrofluoric based products. UNITED's Brite-Cast Investment Remover
also works well, although it is less aggressive and will take
longer.
FLASK TEMPERATURE
Use your regular flask temperatures.
FIRE SCALE
Fire scale is completely eliminated.
CYANIDE TREATMENT
Not recommended.
TECHNICAL ASSISTANCE
Always available…
Call 1-800-999-3463 / 1-800-999-FINE
E-mail / doc@unitedpmr.com
Web-Site / www.unitedpmr.com |