I use to prep the surface of copper, zinc, brass, and magnesium. We would grind the surface because impurities have a tendency to rise to the surface when casting and rolling the metal. We needed an ultra pure surface so the plates could be used in photo etching. Any and I mean any impurtities or foriegn material that was left on the surface would screw the etch up.
We used silcon carbine and aluminum oxide sanding belts and we use to have to grind with oil because of the flamability of magnesium. We would then clean the surface with water spaying out of jets and a mild detergent. To much detergent would contaminate the surface and too little would not clean the oil off.
I have cast zinc by pouring it in a mold and I have cast tantilin and tungston by casting in a vacuume. The methods used has a huge effect of the purity and the characteristic of the metal. You also can trap other impurities like carbon and oxygen during the casting process.
The tantilin was for compacitors and all the metal I have worked with was always actually a mix of metals. This gave it its best electrical or etching qualities. It might only be one percent zinc in the copper but this all makes a huge difference.
We used silcon carbine and aluminum oxide sanding belts and we use to have to grind with oil because of the flamability of magnesium. We would then clean the surface with water spaying out of jets and a mild detergent. To much detergent would contaminate the surface and too little would not clean the oil off.
I have cast zinc by pouring it in a mold and I have cast tantilin and tungston by casting in a vacuume. The methods used has a huge effect of the purity and the characteristic of the metal. You also can trap other impurities like carbon and oxygen during the casting process.
The tantilin was for compacitors and all the metal I have worked with was always actually a mix of metals. This gave it its best electrical or etching qualities. It might only be one percent zinc in the copper but this all makes a huge difference.