Tectyl 121B

Tectyl 121B

0.00 LBS


Tectyl 121B Black Undercoating, is a premium coating blended with asphalt, wax, and mineral spirits. It is a premium rust preventive, chip resistant, and sound dampening undercoating.

Tectyl 121B is a solvent-cutback, thixotropic corrosion inhibitor compound designed to prevent metal wood surfaces from corroding. The cured film provides a resilient matte black finish that is firm and flexible. This powerfully stable and conforming base layer allows for additional coats to be applied without the fear of peeling or cracking.

Tectyl 121B Black Undercoating is approved under Federal Specification TT-C-520B which refers to an asphalt compound suitable for use as a protective coating/sound deadener on underbody parts of automotive equipment.
This requirement was formerly covered by Military Specification MIL-C-62218.

Product Uses

  • Abrasive Resistant Undercoating for Transportation Equipment including Cars, Trucks, Buses, Motorhomes, Trailers and Recreational Vehicles.
  • Can be applied to both Metal and Wood surfaces

Product Performance:

  • Recommended wet film thickness (WFT) of 30-40 mils, it will deposit the recommended dry film thickness (DFT) of 15-20 mils. 
  • Dry to touch in 2-4 hours and fully cure in 16-24 hours. 
  • Covers 46 square ft. per gallon when applied at the recommended dry film thickness (DFT)
  • Can provide up to 5 years of protection on metal and wood substrates at the recommended dry film thickness (DFT). 
  • Can be applied to both new and used surfaces.

Application Equipment Recommendations: 

  • Pumps with ratios of 15:1 or greater are advised for efficient use of container content.
  • Tungsten Carbide Nozzles Tip in the spray gun is recommended.
  • High Pressure Fluid Hose of no less than 3/8 in. diameters is suggested for less than 50 ft. of 3/8 in. hose is required.
  • Low Ratio pumps (15-30:1): operate through 100 ft. of 1/2 in & 50 ft. of 3/8 in. hose for a max of 250 ft. (.021" to .031" tip orifice size)
  • High Ratio pumps(>30:1): operate through 200 ft. of 1/2 in & 50 ft. of 3/8 in. hose for a max of 250 ft. (.021" to .027" tip orifice size)


For additional product information as well as storage and handling requirements, refer to the Product Data Sheet or Safety Data Sheet provided on this page.


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Safety Data Sheet
Product Data Sheet
Trailer Application Points
Spray Equipment Recommendations

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