A good casting should be smooth with no blemishes and faults on any side of the casting. Follow the storing, mixing and burnout procedures of the powder will render perfect results every time
| Incorrect water or powder ratio |
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| Incorrect burnout cycle |
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| Excessive casting forces |
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| Disturbed flask during setting | After investing bench set and do NOT move flask, strip base or remove tape for a minimum of 90 minutes. |
| Over working investment | Ensure all flasks are poured and removed from vacuum tank and put on bench to set by max. 7.5 minutes from starting mixing |
| Waxes too close | Waxes too close together creating a very thin wall of investment. Waxes too close to side or top of flask; ensure min. 5mm gap to top and sides of flask. |
| Slurry too hot | Adjust slurry temperature to 21ºC +/- 1ºC by decreasing water temperature |
| Moulds dried out before burnout | If flasks are left on bench for more than 4 hours before burnout place a damp towel over the tops of the flasks to stop them drying out. Do NOT leave flasks in furnace overnight before burnout. |
| Flask base leak during investing |
Ensure good seal between wax sprue and base. It is suggested that it be sealed with molten wax. |
| Overheated flasks during burnout |
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| Dust on waxes or trees | Ensure once waxes or wax trees are made, they are stored in a dry, clean and dust-free atmosphere. Do NOT store waxes or trees in a dusty environment or investing room. |
| Metal/Flask temperature incorrect | Reduce or increase metal / flask temperature. |
| Rough waxes | Ensure excessive talc or release agent is not used, as this will produce rough waxes and therefore rough castings |
| Flask burnt too quickly after mixing | Do NOT burn out before minimum of 90 minutes after investment. |
| Under or over-worked | Follow the recommended mixing |
| Steam de-waxed for too long | Steam de-wax for a maximum of 60 minutes at atmospheric pressure. If steam de-waxed for longer than 60 minutes, the steam may start to erode the surface of the mould. |
| Metal temperature incorrect | Increase metal temperature first before increasing the flask temperature |
| Flask temperature incorrect | Increase flask temperature |
| Incorrect feed/sprue system | Feed or gate should be attached to the thickest part of the casting. It should be at least 25% of the thickness of the largest cross section of the casting |
| Insufficient centrifugal force | Increase torque first and then RPM of the centrifugal casting machine. Only increase by small amounts each time (5%) |
| Low vacuum when vacuum casting |
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| Not enough over pressure | Only increase over pressure by small amounts each time (5%) |
| Bad vacuum | Change oil in vacuum pump. Pump should be serviced on a regular basis |
| Dust on waxes or trees | Ensure once waxes or wax trees are made, they are stored in a dry, clean and dust-free atmosphere. Do NOT store waxes or trees in the same room that you weigh powder or invest in |
| Rough waxes | Ensure excessive talc or release agent is not used, as this will produce rough waxes and therefore rough castings |
| Under or over worked | Follow the recommended mixing instructions |
| 1st stage burnout hold too short |
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| Flasks de-wax at toohigh a temperature | Do NOT exceed 220ºC in the 1st-stage burnout |
| Flasks placed in furnace too soon after investing | Do NOT burn out before min. 90 minutes after investing |
| Flask placed too close to or touching elements | Leave a minimum of 50mm gap between flasks and elements. |