John Ball

The process of enamels was described by John Ball at the AGM Conference. 

John gave a live commentary to an excellent, silent, video film by Ethel and Arnold Howell when they visited the works of WG Ball, Ltd., at Stoke-on-Trent.

Silica, fluorspar and sodium carbonate - the raw ingredients of enamel are placed into a crucible made of fire clay. The crucible holds about three kilos. It is then brought up to a heat of 1100°C for 24 hours.

A test is then made by placing a sample from the crucible on a steel tile; if the mix is ready, it is poured out on to steel slab.

The difficulty at this point is to turn the crucible through 180° to get all the enamel out. Normally, only 90% can be extracted.

Next, after cooling down a little, the enamel is "slid" off the steel slab into a tray.

When it has cooled down sufficiently (after about 45 minutes), it is broken up and fed into a crushing machine, which will produce lump enamel. This is then washed to remove the dust.

The lumps are then put into a porcelain jar mill with porcelain balls in it. This tumbles the lump enamel around - but unlike a lapidary tumbling machine which works with water - this is a dry process.

After about one hour, it is suitable for a straining through a 50's mesh. (Ready ground enamels should pass through the required mesh size - no lumps.)

In the grinding process, ball mills are washed and vacuumed out when the colour of the enamel is changed. Crucibles are used for one colour only. John sells used ones for a nominal sum, as plant pots!

One of the most tedious jobs, John said, was to gather and pack enamel threads into small bottles. The threads are obtained by "pulling" the molten enamel.

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