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Good housekeeping is the second essential
        When selecting the elements for an alloy, the most important thing is metal purity. Even minute quantities of impurities such as lead, arsenic or antimony (any one of which will probably cause embrittlement) will result in a less than desirable alloy. It is preferable to start with all pure metals, e.g. pure copper and pure zinc. If brass is to be used as master alloy it is essential to know its composition, e.g. ensure it is not a leaded brass.
Fine metal ingots
Labeled crucibles
Maintain a separate crucible for each different alloy used; this will prevent the likelihood of contamination, or lowering of carat ratings from one alloy to the next. The work area and all containers must be scrupulously clean and checked for traces of any contaminants. Be methodical and orderly in all aspects of alloying procedure. These are examples of good housekeeping.

A particular example of bad housekeeping occurred early in my career. For granulating I used a plastic coated drum with a container on the bottom to catch the granules. I didn't empty the drum each time I granulated; in fact, sometimes I would not empty it for up to a fortnight. Eventually I began to get complaints of black spots in the castings. On close examination under the microscope, a small piece of magnetic substance was extracted from a casting. This was identified as iron. The plastic lining in the granulating drum had deteriorated allowing the water to rust the drum. The iron oxide thus formed was collected by the granulation and reconverted to iron during the subsequent melt.

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Last modified: July 26, 1998