Mould polishing and texture advice

[Robin Hewitt]

I am told you can recreate a spark eroded texture by sand blasting.


Now some speculation... a steel cavity might need glass bead blasting as well or rust is instantaneous and you want the cavity side to separate when the mould opens not when the ejectors hit, so don't over key the surface. An Alumec cavity might benefit from anodising if you want it to last but I don't know what that would do to a surface texture. You can frost glass using a mist of hydrofluoric acid, wonder if you could frost an Alumec mould using a spray of caustic soda or frost an anodised mould using a spray of nitric?

Of course you need a good draft angle to avoid smearing the sides when you open the mould. Minimum of 1.5 degrees for ABS