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Trouble Shooting
Investment Powder
Bubbles
In correct water / powder ratio (Investment too thick. Too little water)
Recommended water to powder ratio Vacuum mixing 38:100 / Conventional mixing 40:100
Work time of investment not too less
Appropriate time: 2-3 mins
Work time of investment not too long
Work cycle too long. Investment is starting to thicken while still being vacuumed Bubbles
Vacuum machine faulty-Vacuum leaks
Flashing or Finning
Incorrect water/ powder ratio (Too much water)
Recommended water to powder ratio Vacuum mixing 38:100 / Conventional mixing 40:100
Failure of conveyor belts
( Centrifugal casting) Over pressure (Vacuum casting)
Spin speed is too fast. Torque setting have to match spin speed.
Mixing time not long enough
Appropriate time : 3-4 mins
Overheat metal melting
Rough surfaces
Stream de-wax for too less
Appropriate time 60 mins
Stream de-wax for too long
Appropriate time 60 mins
Flasks put in furnace too soon after mixing
Appropriate time 45-60 mins
Furnaces temperature is too high
Dewax too low temperature/ Lost wax time not long enough *Burnout Oven
Burnout temperature : 220°C250°C
Appropriate time :
60 mins
Sand Casting
Less mixing time
Appropriate time 2-3 mins
Over casting temperature
Furnaces Temperature is too high
Lost wax process not long enough
Appropriate 60 mins
Cleanliness of wax piece
White bensin
Finning
Furnace temperature is too high
Incorrect water/ powder ratio(Too much water)
Recommended water to powder ratio Vacuum mixing 38:100 / Conventional mixing 40:100
Furnaces failure
Moving flask too soon after mixing
Appropriate time 45 mins
Investment cracking
Room temperature is too low/ Too much humidity
Incomplete casting
Defective patturn-Wax tree too hight
The maimum tree height should be between 0.5 inch shorter than the fill level of the flask.
Flaws in a plaster mould
Failure of conveyor belts ( Centrifugal casting)
Over pressuer ( Vacuum casting)
A mixture of plaster and group up old moulds
Incorrect water/ powder ratio ( Too much water)
Recommended water to powder ratio Vacuum mixing 38:100 / Conventional mixing 40: 100
Gas porosity
Incomplete burnout * a minimum of ten hours
Furnaces failure
Calibrate it once every 3-4 months
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