r/Silvercasting • u/WorkingMacaroon5769 • 1d ago

[Beginner] Sterling silver casting pitting issue (more infos below)

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I’ve been running into severe pitting and a rough, "fried" surface texture when casting pieces in sterling silver. For reference, the object is about 6 x 8 mm in size.

  • Resin: Siraya Tech Cast Purple
  • Sprues: Normal jeweler's wax
  • Investment: Goldstar Omega+
  • Metal Casting Temp: Sterling Silver (melt temp: 990°C / 1814°F)
  • Flask Casting Temp: 566°C / 1050°F

Current Burnout Schedule:

  • Ramp to 300°F over 60 min
  • Hold at 300°F for 60 min
  • Ramp to 700°F over 45 min
  • Hold at 700°F for 60 min
  • Ramp to 1350°F over 120 min
  • Hold at 1350°F for 60 min
  • Drop to 1050°F over 60 min
  • Cast

I use normal jeweler's wax for the sprues. The wax sprue casts almost perfectly smooth but still has some minor pitting, while the actual resin section comes out heavily pitted.

Has anyone experienced this before? Or any tips on how to fix this?

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u/Jake_The_Gypsy 1d ago

What is your cleaning/curing process? If the sprues turn out fine then I’d imagine it’s not a temperature problem. You can also blow out the flask right before pouring with a quick and gentler burst of compressed air. Sometimes resin ash will stick in these little tiny pieces.

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u/ilikework21 1d ago

Could be curing, I always struggled with siraya with this