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BULK: RP-342 "BLACK" Rust Preventive Spray

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  • BULK: RP-342 "BLACK" Rust Preventive Spray - 1 Gallon can
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  • BULK - COSMOLINE RP-342 "BLACK" Military-Grade Rust Preventive Spray - 5-GALLON PAIL
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Ships UPS Ground (excluding HI & AK)
IN-STOCK. Ships Same Day (when order placed before 4:30pm EST).

BULK:  READY-TO-SPRAY  /  GALLONS & 5-GALLON PAILS  (Sprayer Not Included)     

(To view this product in our bestselling, convenient aerosol cans, click here.)
(Need a sprayer?  Here's an easy-to-use, effective and economical model that works great with our RP-342. click here.)
(Got your own air compressor?....check out our Spray Gun & Extension Wands, click here.)

Cosmoline RP-342 "BLACK" Military-Grade Rust Preventive

Our Strongest, Longest-Lasting (and Fastest-Drying) Rust Preventive Spray, PERIOD!

   *  Offers the highest concentration of Industrial-Grade Cosmoline® available in a convenient Aerosol Can (now in Bulk).
   *  Same formula as our bestselling RP-342 "Heavy", but now in a surface-concealing, matte Black!  (not translucent).
   *  1-coat protects all metals, iron, steel (stored Indoors or Outdoors) for Years!
   *  Newly formulated!  Our thickest, longest-lasting Rust Preventive Spray.
   *  Produces dry-to-the-touch, black (not translucent) petroleum wax coating.
   *  Faster-Drying formula allows for quicker handling and/or shipping.
   *  Withstands severe outdoor exposure, salt-laden atmospheres, acid & caustic fumes and other damaging environs.
   *  Repels water and will not wash off in salt water environments.
   *  Will not crack, craze, peel or flake and remains slightly flexible over time.
   *  Exceptional Vehicle Undercoating Product (Autos, Trucks, Buses, Trailers, etc.) - Road salt, debris and chemicals - No Problem!
   *  Aggressively adheres to imperfect surfaces and offers self-abraiding characteristics.
   *  Modeled after Military Specifications:  MIL-PRF-16173, Grade 4 and MIL-C-83933.
   *  Trusted since World War II.  Our Bestselling Aerosol - commercial customers, US Armed Forces, Government & Do-it-Yourselfers.
   *  Your Satisfaction with this product is Guaranteed!*


COMMON APPLICATIONS INCLUDE (but are not limited to):

   *  Vehicle undercarriage / undercoating (cars, buses, trucks, etc.) - See RP-342 Undercoating FAQs.
   *  Parts & equipment storage  
   *  Overseas transportation
   *  Heavy machinery & equipment
   *  Packaging
   *  Dies, molds, lathes, shafts and beams
   *  Offshore Drilling equipment, platforms & infrastructure
   *  Farm implements   
   *  Boat shafts and propellers
   *  Marine fittings
   *  Rifle & other firearms preservation/storage
   *  Garden tools
   *  Lawn mower blades
   *  and any other surface or part that might rust on you... 

DOWNLOADS:  Product Data Sheet / Overview     RP-342 Safety Data Sheet (SDS)        


Make sure surface is reasonably clean and dry (not oily or greasy). Spray generous, uniform coat.  For more very long storage durations, a second coating can be applied if desired within 30 minutes.  Complete setting of protective coating takes approximately 1 hour after spraying.  Typical first application Dry Film Thickness is 2.0 Mils (51 Microns)

RP-342 "BLACK" can be easily removed with any over-the-counter petroleum solvent. Examples include mineral spirits, paint thinner, naphtha, diesel fuel, or our very own Cosmoline Remover.  Our Cosmoline Remover is very effective, but also considerably more expensive than the other options mentioned.

RP-342 "BLACK" is modeled after the following military specifications: MIL-PRF-16173E Grade 4, Class 1 and MIL-C-83933

* Certificates of Conformance are not available for this product. 

18 Months when stored in prudent conditions (cool, dry, shaded).

* Ozone Depleting Substances - Aerosol products were not manufactured, do not contain, and were not packaged using any Class 1 or Class 2 ozone depleting substances as defined by the clean air act.  
* Non-Chlorinated (no chlorinated solvents).


 Product Videos

Cosmoline RP-342 - Vehicle Undercoating Overview
  • Cosmoline RP-342 - Vehicle Undercoating Overview
    Showcasing Cosmoline RP-342 (Military-Grade) Vehicle Undercoat...

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Phone: (866) 802-2906
Fax: (866) 607-5965
Cosmoline® and Rust-Veto® are registered trade names of Houghton International