Part 3 of the Investment Checkoff List Series we will cover using investment.
This is meant to serve as a reminder or quality-control list. The information in parenthesis is a possible condition which may result from lack of, or improper control of the parameter.
- Water tempreture.............Too hot, sets too quick causing nodules; too cold sets too slow, causes investment weakness and/or watermarks
- Investment tempreture.....Too hot, sets too quick causing nodules; too cold sets too slow, causes investment weakness and/or watermarks
- Investment storage..........Moisture may cause weaking of investment (fins)
- Ratio of investment to water...Too much water extends work time and weak investment; too little cuts time causing grainy surface or nodules
- Mixing of investment........Insufficient vacuum causes nodules or bubbles on pieces
- Turbulence on filling flask....Fine pieces may be bent or broken off
- Vacuum on investment......Insufficient vacuum causes nodules or bubbles on pieces
- Vibration of investment......Insufficient vibration causes nodules or bubbles on pieces; too long may cause fins or spauling if investment starts to set
- Time to setting up.............Too long causes weakness; too short grainy surface or fins
- Moving to early/rough movement.....Results in fins or cracks
- Cure time after investing....placing in oven too early may cause fins or spauling