Armstrong Contracting and Supply Corporation: Sprayed "Limpet" Asbestos Machine Operating Instructions

An undated 25-page operating manual from Armstrong Contracting and Supply Corporation, the U.S. applicator of Sprayed "Limpet" Asbestos, for the HA Type spray machine and its multi-jet spray gun: the equipment a job needs, checks before work starts, hose connections, how the machine meters dry asbestos fiber from a hopper on a spiked belt and blows it to the gun, where water jets wet it about nine inches out, a fault-finding checklist, pressing and hand tools, safety rules, and cleaning and maintenance, with parts drawings. It recommends "that each member of the spray crew wear a dust respirator at all times during the application process", approved by the U.S. Bureau of Mines, and to "see that the man feeding the machine also wears one". Crews are to clean excess damp fibers from surrounding surfaces at the end of each day and to clear fiber from the machine by hand, and the gun is to be shut off in two steps because a quick release "causes dry fiber remaining in the hose to be blown into the air."

What it shows

• Equipment and set-up (pp. 2–5): the spray machine, a 6- or 9-jet multijet gun, fiber, air and water hoses and regulators, a compressor, and a pressure tank for the TS.2 emulsion used on porous surfaces; the checks a foreman made before a job (water, air, power, scaffolds, material).
• How it worked (p. 6): dry asbestos fiber was lifted from a hopper by a spiked belt (the "creeper sheet"), metered by a brush, blown through a 2-inch hose and wetted by water jets about nine inches beyond the gun, which was held 18 to 20 inches from the surface at about 45 degrees.
• Fault-finding (pp. 7–10): fiber too wet, too dry, too slow or too fast, "Fiber Flying About," no fiber, uneven surface.
• Pressing, tools and safety (pp. 10–12), including "Always wear a respirator; see that the man feeding the machine also wears one."
• Cleaning and maintenance (pp. 12–14): fiber cleared from the machine's doors, drums and fan blades by hand, daily, weekly and monthly.
• Drawings (pp. 15–25): the HA Type machine and its parts, the spray guns and two-way valve, the pressing tools, the hook-up, and the trigger positions, with the warning that a quick shut-off "causes dry fiber remaining in the hose to be blown into the air" (Exhibit 11, p. 25).

About this copy

It carries Plaintiff's Exhibit 12462.00 and WV-05539 and Defendant's Exhibit ACandS 57 stamps. It is undated. It describes only the HA Type machine, not the later "K" Machine of Armstrong's 1962–64 Construction Manual section D-180, so it is probably the earlier of the two.

Related

• Sprayed Limpet Asbestos
• W. G. Wright to J. D. Pennington of J. W. Roberts on the Health Hazard of the Limpet Asbestos Spray Process (1960)
• Armstrong Contracting and Supply Corporation: Sprayed "Limpet" Asbestos (c. 1963)