---
product_id: 219019337
title: "Cosmoline RP-342 Black Rust Preventive Spray (Military-Grade) 6-Cans"
brand: "cosmoline direct, llc"
price: "B/.383"
currency: PAB
in_stock: true
category: "Cosmoline Direct, Llc"
url: https://www.desertcart.com.pa/products/219019337-cosmoline-rp-342-black-rust-preventive-spray-military-grade-6
store_origin: PA
region: Panama
---

# Dries in 25 mins Withstands extreme temps Years of rust protection Cosmoline RP-342 Black Rust Preventive Spray (Military-Grade) 6-Cans

**Brand:** cosmoline direct, llc
**Price:** B/.383
**Availability:** ✅ In Stock

## Summary

> 🛡️ Lock in Legendary Rust Protection — Because Your Gear Deserves the Best

## Quick Answers

- **What is this?** Cosmoline RP-342 Black Rust Preventive Spray (Military-Grade) 6-Cans by cosmoline direct, llc
- **How much does it cost?** B/.383 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.com.pa](https://www.desertcart.com.pa/products/219019337-cosmoline-rp-342-black-rust-preventive-spray-military-grade-6)

## Best For

- cosmoline direct, llc enthusiasts

## Why This Product

- Trusted cosmoline direct, llc brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Fast-Drying Formula:** Ready to handle your gear in under 30 minutes, so you get back to work faster.
- • **Military-Grade Durability:** Trusted by U.S. Armed Forces since WWII for unmatched rust defense.
- • **Invisible Armor with Style:** Sleek black petroleum wax finish conceals imperfections while resisting cracking and washing off.
- • **One-Coat, Long-Term Shield:** Single spray protects metal surfaces indoors or outdoors for years—no reapplication hassle.
- • **Versatile Industrial Strength:** Perfect for vehicles, machinery, firearms, marine gear, and thousands more applications.

## Overview

Cosmoline RP-342 is a military-grade, fast-drying rust preventive spray that delivers a durable black petroleum wax coating. Trusted since WWII, it protects metal surfaces from rust, salt spray, and harsh environments for years with just one coat. Ideal for vehicle undercoating, heavy machinery, firearms, and marine equipment, it dries in 25 minutes and resists cracking, blistering, and washing off, ensuring long-lasting corrosion defense indoors and outdoors.

## Description

Military-Grade Rust PreventionModeled after Military Specifications: MIL-PRF-16173, Grade 4 and MIL-C-83933.Application:IMPORTANT #1: Make sure your surface is clean and dry (not oily or greasy) to ensure best possible adhesion.IMPORTANT #2: RP-342 is a heavily-concentrated rust preventive. For best results, each spray can should be shaken vigorously for about 2 minutes to ensure a uniform coat. The aerosol cans should also be shaken intermittently during longer application sessions.GENERAL INSTRUCTIONS - Spray a generous, even coating on your surface and let dry. While a single coating will provide exceptional protection, additional coats can be applied if desired. If applying multiple coats, always let previous coats dry completely before applying the next coat. Ideally, it’s always preferable and recommended to apply over a non-rusted surface, however, RP-342 can be applied over moderate surface rust. RP-342 will prevent surface rust from spreading. RP-342 should not be applied over flaking or pitted rust…..these advanced types of rust should be treated prior to applying RP-342. The typical first application dry film thickness is 2.0 Mils (51 Microns).Common Applications Include (but are not limited to):- Vehicle undercarriage / undercoating (cars, buses, trucks, etc.) - the most popular application!- Parts & equipment storage- Overseas transportation- Heavy machinery & equipment (storage & in-use applications)- 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- 1,000s of applications! Reliably protects any surface that might rust on you!

## Features

- OUR STRONGEST, LONGEST-LASTING & FASTEST-DRYING Rust Preventive Aerosol, PERIOD! 1-coat can reliably protect any metal, steel, or iron surface (parts, equipment, tools, machinery, etc.) for Years!.....indoors or outdoors.
- DURABLE & TOUGH – Will not crack, craze, blister, run or “wash off”. RP-342 produces a dry-to-the-touch (non-tacky), amber, BLACK petroleum wax coating (perfect for concealing unsightly surfaces) that stands up to long-term salt spray, extreme temperatures and other harsh environments.
- EASY-TO-APPLY: Just spray onto a dry surface, dries in about 25 minutes; You’re Done!
- TRUSTED SINCE WWII – has been widely used & trusted by the U.S. Armed Forces, government agencies, commercial companies, and DIYers/consumers for generations.
- 1,000s of APPLICATIONS across commercial and private industries. Vehicle undercoating is one of the most popular applications. Easily stands up to road salt, chemicals, road debris and won’t wash off like many other undercoating products. One application/coating can protect for years.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0888PB5G7 |
| Age Range Description | Adult |
| Best Sellers Rank | #60,938 in Automotive ( See Top 100 in Automotive ) #208 in Care Corrosion & Rust Inhibitors |
| Brand Name | Cosmoline Direct, LLC |
| Color | Black |
| Color Code | '#000000' |
| Container Type | Can |
| Coverage | Long-term protection for various metal surfaces in diverse environments |
| Customer Reviews | 4.7 4.7 out of 5 stars (213) |
| Dry Time In Hours | 0.42 |
| Finish Type | Gloss |
| Indoor Outdoor Usage | Indoor, Outdoor |
| Is Waterproof | True |
| Item Form | Aerosol |
| Manufacturer | Flywheel Distribution, LLC |
| Model Name | RP-342 |
| Model Number | RP-342 |
| Paint Type | Spray |
| Part Number | 342-1032-6 |
| Size | 12 Ounce (Pack of 6) |
| Special Features | Fast-Drying |
| Specific Uses For Product | Vehicle Undercoating, Car Undercoat, Truck Undercoating, Rust Prevention, Rust Preventive |
| Surface Recommendation | Metal |
| Unit Count | 72 Ounce |

## Product Details

- **Brand:** Cosmoline Direct, LLC
- **Color:** Black
- **Finish Type:** Gloss
- **Indoor/Outdoor Usage:** Indoor, Outdoor
- **Paint Type:** Spray
- **Size:** 12 Ounce (Pack of 6)
- **Special Feature:** Fast-Drying
- **Specific Uses For Product:** Vehicle Undercoating, Car Undercoat, Truck Undercoating, Rust Prevention, Rust Preventive
- **Surface Recommendation:** Metal
- **Unit Count:** 72 Ounce

## Images

![Cosmoline RP-342 Black Rust Preventive Spray (Military-Grade) 6-Cans - Image 1](https://m.media-amazon.com/images/I/51DyRGK+acL.jpg)

## Available Options

This product comes in different **Size** options.

## Questions & Answers

**Q: Por15 my van frame, inner fenders, axles, etc now deciding if i need to shoot my chassis black paint & cosmo or if i can skip painting? uv protection?**
A: As with everything, preparation is key. Paint alone does not cut it here in upstate New York (The Rust Belt). In my case, the entire underside of a ‘08 Tundra here’s what I did. A good up close and personal power washing. Then pump sprayed the correct mixture of Salt-Away, rinsed thoroughly and let dry. Did those steps a second time just because I’m ocd. Black Star where necessary, primer when ready and topcoat with black paint. Mask off entire exhaust, rotors, calipers, and anything that could be oversprayed,pull tail lights and fender liners. I used cosmoline rp-342 black, 15, 12oz rattle cans, shaken continuously and done on a nice day with no wind and 65 degrees. Does not need to be sprayed heavily and can be second coated. I used a can or 2 of the “Heavy” amber formulation when coating any of my painted areas, such as behind the cab and front of bed, under tailgate and vulnerable areas in the engine compartment. Definitely dress like your installing fiberglass insulation because this stuff stays “Anywhere it touches”, getting it off of your skin is not fun. All of that work has just been put through a pretty nasty winter here with salt getting encrusted everywhere and anywhere it could, with trips to the power washer when I could, to get it off. I know this isn’t a long test duration, but that cosmoline is holding its own and then some. I will never use anything else when I do another vehicle, worth every penny! This stuff is Mil-spec for a reason.

**Q: Can this be applies over gas metal pipes?**
A: yes but your pipes will be sticky forever

**Q: Can this be applied over rust-oleum automotive rust reformer or vht rust converter?**
A: Yes, RP-342 can be applied over any DRY surface (not oily or greasy) to ensure the best possible adhesion.

**Q: Is Spray can compatible with wands for spraying inside rockers?  cap male or female  - tube on cap or tube on can?**
A: Hello, unfortunately the cosmoline tip is a male. The wands spray top that I got from a different cavity wax company are female. If you’re handy enough, I’m sure it’d be possible to retrofit the cosmoline spray tip to accept the wands brass fitting. My thoughts on that would be to carefully drill the tip to just undersized of the brass and insert, followed by wrapping with hot glue. I know this is possible because I’ve had to hot glue the extension wands onto the spray tips to keep them from dislodging. Hope this helps!

## Frequently Bought Together

- Cosmoline RP-342 Black Rust Preventive Spray (Military-Grade) 6-Cans
- Cosmoline RP-342 Heavy Rust Preventative Spray (Military-Grade) 6-Cans
- Rust-Oleum 248658-6PK Rust Reformer Spray, 10.25 oz, Black, 6 Pack

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*Product available on Desertcart Panama*
*Store origin: PA*
*Last updated: 2026-10-12*