Raymond Jackson

Surface Preparation

Thus far, the surface of the copper had been annealed, pickled and then abraded using a glass fibre brush. This produced a matt reflecting surface for the fired enamel flux. I now tried other treatments to the copper surface. Incidentally, I found from experience how important it is, after pickling, to wash the copper thoroughly to remove all traces of chemical. One effective treatment is a light scrub with a toothbrush dipped in ammonia to which has been added a few drops of detergent. I followed this by washing in hot running water until the water no longer formed droplets but shed from the surface.

I now modified this process further having studied the article by Carpenter 6 on metal preparation. After the pickling to remove the oxides after annealing, I dipped the samples in a warm 25% solution of bright dip or aqua fortis for two to three minutes. This removed any trace of remaining oxide and initially attacked the copper itself. This made the copper brighter, a little more yellow in colour and according to Carpenter produces a smoother surface with the grain boundaries not very evident - see Figure 7.

2005Winter copper 1

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