After doing the math a company finds recoating rather than replacing its rooftop cabling system will yield substantial savings.

By using a silicone sealant to recoat failing PVC-jacketed electrical cable, a major Midwestern auto manufacturer protected its wiring — and saved a bundle.

During a routine inspection, facility engineers noticed the company's rooftop cabling system (approximately 15,000 linear ft of medium-voltage wiring) was dry and cracking — the victim of weathering and ultraviolet (UV) exposure. Lengthy sections showed signs of possible water intrusion. Something would have to be done fast.

Engineers felt the only certain remedy would be to replace the cable, but that meant big expenses and downtime.

The company investigated an alternative: applying Dow Corning 700 Industrial Grade Silicone Sealant to the cable. Applied in a temperature of 77°F (25°C) and in 50% humidity, this durable silicone sealant forms a tack-free skin within 15 min, and sections up to ⅛-in. thick cure in about 24 hr. (Humidity, degree of confinement, and application thickness all affect the cure time.)

Once cured, the tough, rubbery solid remains flexible, allowing it to withstand UV light, ozone, rain, and extreme outdoor temperatures for a typical life span of more than 20 years.

After testing the adhesion and UV protection of the silicone formulation, the auto manufacturer hired an industrial painting contractor to recoat 7,200 ft of the cable. The contractor developed some simple tools and applied the material at an average thickness of ⅛ in. to ¼ in.

Evaluating the project at this point, engineers estimated recoating rather than replacing the cable had saved the manufacturer more than $400,000.

Impressed, the manufacturer decided to seal the remaining 7,800 ft of cable.

The result: an estimated total savings of close to $850,000. The Table (original article) shows how they calculated these savings.
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