WAXING
Wax to a minimum of .3mm for single units and .5mm for bridge work. Avoid sharp angles and wax to provide for an even thickness of porcelain.
SPRUING
The indirect method is recommended. Use 6 or 8 gauge sprues for pontics and 10 gauge sprues for copings. Use a pre-made or hand formed runner bar. Sprue length should be precisely 1/4 of an inch.
INVESTING AND BURNOUT
A phosphate-bonded high heat investment without Carbon content is recommended. Follow the manufacturer’s instructions for mixing powder and liquid. Cover the pattern with no more than 1/8″ – ¼” of investment. Use a double ring liner. BURNOUT- Place in a cold furnace and raise up to 1550ºF. Heat soaks at 1550ºF for one half hour. Increase 5-10 minutes hold time for larger or multiple rings.
MELTING/CASTING
Use a multi orifice torch tip with gas wide open and 40 PSI oxygen. Propane 2-4 PSI maximum. If re-melting, add 50% new metal to button. Using a high heat crucible, heat ingots until they turn white and slump. After alloy slumps, make sure all surfaces are white hot before releasing casting arm. DO NOT break protective surface oxide. By induction the casting temperature is 2550ºF (1400ºC) with a 5 second heat soak.
DEVESTING AND FINISHING
Bench cool for 10 minutes and water quench. DO NOT USE HYDROFLUORIC ACID OR ACID SUBSTITUTES. To devest, blast with aluminum oxide. To finish, use only aluminum oxide stones and wheels, diamonds, or carbides.Grind and polish with adequate ventilation only.
CONDITIONING
Oxidize (degas) framework under vacuum starting at 1000ºF, raise temperature to 1875ºF, 100ºF per minute. Release vacuum, remove and bench cool. A thin straw-colored (goldish-brown or greenish) oxide should appear on the metal surface. Proceed with opaquing according to porcelain manufacturer’s instruction.
CAUTION
This alloy contains Nickel and should not be used for persons with known Nickel sensitivity. Contains Beryllium. Grind and polish with adequate ventilation only.
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