In a recent Shure fatboy rebuild from 1941 and 1943 the re-plating of

the zinc frames were called for, but it was up to me first to get rid of years

of nicotine build-up from chain-smoking radio broadcast announcers,

close-talking and leaving their smelly shpit in and on the mic elements.

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(Cigar smokers invariably spit tiny chunks into the grills.)

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The mics were both BC types ?with three or four layers of cloth and

fine copper metal screen in between, so they ?did a great job of? collecting.

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All the inside components were trashed. The mic elements and magnets,

floating on the springs, were utterly gone. The springs, not stainless or phosphor

bronze, crumbled into a primordial ooze that turned into a miniature

coal mine of solidified tar.

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After getting all the screws and parts out, the mic shells were boiled

in a mixture of kerosene and Methyl Ethyl Ketone using a boiling jacket

and a small tub from a lab bench. The last material to let go was

the contact cement globs ?adhering the inside fabric shells and

screens to the castings.

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The solvents were replaced three times during the 48 hour process, and

each time save the last, smelled like an elevator with cigar smokers

stuck inside it. I felt like coughing myself. You know BC mics had

cough buttons, yes?? No wonder. I could almost feel the congestion

building up. I started out in BC engineering as a studio tech and

you know who was customarily assigned mic chores, which were

especially odious when having to deal with 77’s with their HV supplies

melting down from goo in the ribbons.

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Hal Mandel

W4HBM