posted 05-16-2005 03:24 AM                    

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Design of the original Series One/Two discs proved to be a disaster. An acetate-based form of plastic appears to have been used, which created the problem of it having to be kept at a relatively stable temperature. This was all the more critical as the acetate layer was riveted onto an aluminium backing (flywheel) disc. Ian Macnaught (Scottish Cinema Organ Trust) sums up the situation thus: “If the disc temperature was allowed to go up and down – like hot during the day, and cool at night – it kneaded the plastic, causing a catalytic action, which resulted in a vinegar-smelling gas to be given off. The loss of mass in the material then allowed decay of the acetate, into a ‘toffee’ consistency, which gradually poured itself out of the bottom of the disc assembly.

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