United
Precious Metal Refining, Inc.
Ag Casting Grain Type "PT-1"
Sterling Silver “PT-1” is a proprietary platinum based sterling
silver designed to achieve maximum hardness and eliminate fire scale
and porosity. Sterling “PT-1” has been developed to have a hardness
exceeding standard sterling silver, while still retaining the
advantageous 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 deoxidized gold casting
alloys should have less trouble adjusting to the appearance of these
silvers.
MELTING
Temperature range 970 - 1010 C / 1778 - 1850 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 Boric
Acid. Do not use Carbon Containing Fluxes or Charcoal. Skim any
surface oxides off the surface before stirring.
QUENCH TIME
15 - 20 minutes.
HARDNESS
This silver as cast will have a hardness similar to traditional
sterling silver. AND HEAT It can be hardened further by heat
treatment at 300 C / 575 F for one hour, TREATMENT and air cool.
INVESTMENT
Most standard investment removers will successfully remove the
investment REMOVAL 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.
SOLDER TREATMENT
Soldering heat should be as low as possible to prevent low
temperature eutectic nodules from forming.
TECHNICAL ASSISTANCE
Always available…
Call 1-800-999-3463 / 1-800-999-FINE
E-mail / doc@unitedpmr.com
Web-Site / www.unitedpmr.com |