J. H. Zettel to R. M. Billings on Converting Marinite from Amosite to Chrysotile (1973)

A two-page Johns-Manville memo, "Marinite with Chrysotile," from J. H. Zettel of the Research & Development Center to R. M. Billings, dated May 14, 1973, with copies to H. B. Moreno, S. Lane, R. A. Stapleton, H. E. Konrad, C. P. Weber and H. W. Gilbert. The chart it mentions is not in this copy.

What it shows

The memo sends "a chart showing the various steps necessary to convert Marinite from Amosite to Chrysotile fiber," with target dates "for all products with the exception of Marinite 23." A production run the week of June 11 was to make 28, 38 and 50 pound-per-cubic-foot boards to replace the existing grades, including Molten Metal Marinite. It mentions two approaches to Marimet, one of them "an asbestos-free calcium aluminate bond."

The program was "a very ambitious one with full production being anticipated by the end of October in the Marinite 38 and full production achieved in molten metal Marinite and Marimet by February 1974." Coast Guard qualification tests and customer evaluations were harder to schedule.

Marinite had been made with amosite since 1936. Three months later, J-M's medical director wrote about the effort to take amosite out of Marinite and conditions at the Billerica plant (Dr. George W. Wright to H. Moreno, 1973).

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