I’ve been trying to cast a couple 39mm silver rounds and I’m consistently getting this defect as seen in the attached photo. It has been common among all four attempts and is usually present on only one side of the round.
Some notes about my setup and methodology.
- Model is properly printed, cleaned and cured Siraya tech castable resin
- Nine hour burnout 300->700->1350->950 as per ULTRAVEST instructions
- Metal is 999 fine silver
- Metal melted with oxypropane using a reducing flame
- Vacuum casting table
How long do you typically leave the flask under vacuum while the metal is cooling? I’ve been holding for about 20 seconds based on a suggestions read elsewhere. Should the vacuum run until the button starts solidifying?
Thanks for any tips. I’m very new and have only had a vacuum table for a couple weeks at this point.