Working with any precious metal poses its own unique challenges. Having the correct information before beginning can make all the difference. Sterling silver is no exception. These handy charts will help guide you through some of the silver specifics.
INVESTMENT CASTING
FABRICATION AND SOLDERING
NOTE Ingot Molds: Use two-piece vertical molds. Note: Avoid using horizontal slot-type molds for ingot casting as a shrink down of the center of the ingot will cause an area of porosity down the center of the rolled or drawn stock. Preheat the mold and use a light oil or spray graphite to keep the metal from sticking.
Did you find this information useful? See more helpful articles and charts in our new Findings 2018 - 2019 catalog.
INVESTMENT CASTING
| Traditional Sterling Silver | Sterlium Plus® | Continuum® Sterling Silver | |
|---|---|---|---|
| Notable Attribute | Age-Old Tradition | Tarnish Resistant | Harder Sterling |
| Casting Temp | 970°C / 1778°F | 1010°C / 1850°F | 1010°C / 1850°F |
| Flask Temp | Adjust to size and weight of castings | Adjust to size and weight of castings | Adjust to size and weight of castings |
| Casting Flux | Boric acid–skim off before casting | Boric acid–skim off before casting | Boric acid–skim off before casting |
| Quench Time (4"x8") Flask |
15-20 minutes | 20-25 minutes | 5 minutes (for softer) 25 minutes (for harder) |
| Investment Removal | Any proprietary investment remover | Any proprietary investment remover | Any proprietary investment remover |
| Pickling After Casting | Required to remove black oxidation | Usually not required, castings are white | Minimally required, castings are light brown |
| Reuse | 50% scrap / 50% fresh metal | 50% scrap / 50% fresh metal | 50% scrap / 50% fresh metal |
| Note | Remove all investment residues before reuse | Remove all investment residues before reuse | Remove all investment residues before reuse |
FABRICATION AND SOLDERING
NOTE Ingot Molds: Use two-piece vertical molds. Note: Avoid using horizontal slot-type molds for ingot casting as a shrink down of the center of the ingot will cause an area of porosity down the center of the rolled or drawn stock. Preheat the mold and use a light oil or spray graphite to keep the metal from sticking.
| Traditional Sterling Silver | Sterlium Plus® | Continuum® Sterling Silver | |
|---|---|---|---|
| Notable Attribute | Traditional | Tarnish resistance, more malleable and ductile, no fire scale | Mildly more tarnish resistant, harder sterling, no fire scale, stone retention, more resistance to fire cracking, maintains form, resists misshaping, holds finish longer |
| Pouring Temp | 982°C / 1800°F | 1030°C / 1886°F | 1030°C / 1886°F |
| Flux | Borax or Boric acid - skim before pouring | Boric acid - skim before pouring | Boric acid - skim before pouring |
| Quenching | Quench quickly after pouring | Quench quickly after pouring | Quench quickly after pouring |
| Rolling | Take 50% - 70% reduction before annealing | Take 50% reduction before annealing | Take 50% reduction before annealing |
| Annealing | 676°C / 1150°F, 20-30 minutes |
676°C / 1150°F, 20-30 minutes | 676°C / 1150°F, 20-30 minutes |
| Pickling | Ingots will need to be pickled to remove oxide | Ingots will need to be pickled to remove oxide | Ingots will need to be pickled to remove oxide |
| Cleaning | Scrub ingots clean before use | Scrub ingots clean before use | Scrub ingots clean before use |
| Soldering | Regular silver solders | Regular silver solders | Regular silver solders |
| Fire Coat |
A fire coat should be applied | A fire coat should be applied | A fire coat should be applied |
| Solder Flux | Use plenty of flux for soldering | Use plenty of flux for soldering | Use plenty of flux for soldering |
Did you find this information useful? See more helpful articles and charts in our new Findings 2018 - 2019 catalog.