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  • Durable, OEM-approved Heresite® coating
  • Protects coils from corrosion
  • For coils in coastal regions, or in industrial or agricultural settings; protects refrigeration coils against food acids
  • Causes negligible transfer loss
  • Gray color coating


DuraCoil is a specially formulated coil and surface protectant for HVACR components. The product is an aerosol based, air-dry phenolic gray colored coating designed to extend the life of the coil or other system component in a corrosive environment. The coating is field proven – used successfully by OEMs for many years - but now available through Nu-Calgon as DuraCoil for field service when durable protective coil treatment is required to extend service life.

DuraCoil is formulated to extend the service life of the coil or other system component in a corrosive environment. Coils located in coastal regions, industrial/agricultural production settings or refrigeration applications to protect against food acid. Perfect for a new installation if the coil was not factory supplied with a protective coating or to repair an area of an existing coating already in service.

Packaging Size Part Number Additional Info
11 ounce can 4083-91 Gray color
11 ounce can 4083-90 Brown color - discontinued


This product must be used in accordance to the following directions by HVACR professionals only.

  1. Coil must be clean and dry — free of dust, dirt, grease and grime. Clean with a Nu-Calgon coil cleaner if necessary. Remove any equipment panels necessary and properly cover any adjoining surface that needs to be protected. 
  2. Disconnect all power to the equipment before use. Do not spray near sparks, heat or open flame.
  3. Use only with adequate ventilation; avoid breathing of vapors and spray.
  4. For best results, spray when the outdoor temperature is 50°F or above.
  5. Shake the canister well before using. Shake canister for one minute after you first hear the mixing ball rattle within the canister.
  6. Apply coating in several thin, even coats over the coil or metal surface.
  7. Allow adequate drying time before turning on the system.

Note: For future coil cleanings after DuraCoil has been applied, consider Nu-Calgon coil cleaners such as Tri-Pow’r, Special HD CalClean, Cal-Green, TriClean 2x, Evap-Green, Evap-Pow’r or Green Clean. For additional questions, contact Nu-Calgon.

Product Information:

Literature Downloads

Download the product bulletin and other relevant literature here.


Download a low resolution file of the product label here.

Product Safety

RTK Information

2611 Schuetz Rd. St. Louis, MO 63043
  • Telephone: 800.554.5499
  • Email:
  • Hours: Mon–Fri: 8:00am - 5:00pm (Central Time)

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