MSNOR Cosmoline RP-342 Heavy Rust Preventative Spray (Military-Grade) 1-Can

It's the best of the best. Plain and simple.

I use this a a protective coating under my vehicles for winter, coats well, easy to apply, has "straw" to spray into small areas.

This is the same thing the GM truck uses on the frame at the time of new assembly as their frame is in raw steel state and dipped in this same product and compatible with their factory rust proofing plus its what the military uses to protect a lot of equipment from corrosion. It does have to be maintained on the vehicle as road debris and scrapes can remove it. Gm warranty requires re-touch up of this factory scaled off material on the factory frame to be done by GM service personnel under their warranty service and they are responsible and required by GM for them to do this mandatorily when discovered under their warranty provisions, but you have to make sure they do it..Easy to use for protection of firearms storage and GM or other makes touch ups on frames and inner body panels to prevent the start of corrosion. It is one of the only products compatible with the factory coating in terms of it won't break the factory coating down like a oil based protector or undercoating like fluid film would..Also stays where it is and does not run. Clear or black.

I have used this product, and the black product for over 3 years. I can tell you this stuff really works. I live in a the northern part of the US where salt is applied many times during the winter. I have used this on 5 vehicles and all of them look rust free. Even the mechanic said whatever I was using was magic as the bolts and metal look like new after 30K miles and three Iowa winters. I also have prayed this on, then sprayed it with a pressure washer, and it still hold on and does not show any rust. This is a great investment for your automobile and way cheaper than the dealer. The stuff does smell like craze for the first two weeks, but after that, no smell and no rust.

Worked for me

Original use for undercoating car. After multiple washes and salty/rocky roads, >98% still on and looking good. Used method of: brushing/sanding rust, clean, rust converter, and then RP 342. Reapplied a couple areas for longevity. Will have to see how long it lasts. Sprayed spare heavily rusted metal (no cleaning) and some galvanized steel to see effectiveness or reaction. Bought 6 bottles, only used 2 for undercoating - only did frame (rest of car AL).Coated tons of outdoor appliances - trailer, garage door, shelf, etc. All looking good.UPDATE: June, 2023- Ok, so I have done a lot of testing with various rust preventatives. Couple ongoing tests outdoors, under cars, etc. Mostly focused on lanoline (Fluid Film, Blast Surface Shield) and cosmoline (RP-342, AMS Oil Heavy Metal Protector). Main takeaways:1- Do NOT use only Rustoleum rust converter spray. Does not protect well, flakes off over time, rust continues underneath. Unless there is mild rust or very clean new surface, it will chip and/or flake away over time. Can coat Rustoleum with Fluid Film (FF) or RP-342, but why use Rustoleum in the first place?2- RP-342 works well with mild to moderate rust, not heavy rust. Be sure to scrape and wipe most rust away.3- RP-342 works best with no physical contact. If a major scrape/dent, RP-342 will not cover all of it. I like putting this on car frames and inside car frames where no road grit will wear it down. Use FF for commonly exposed areas to movement/rocks/etc.4- Haven't had a galvanized steel reaction yet, but could do better testing here.5- Fluid Film vs RP-342? Depends on use, either is fantastic. Think of RP-342 as a heavy mule. Does all the hardlifting, but can't knock it over (big scratches) or move it (does not seep once dry). Stays put and provides excellent protection. Fluid film is thinner, yet sticky. Attracts dust and bugs (no biggie), seeps into new scratches, eventually can be washed off (like, eventually and takes a lot to do it).I found RP-342 to be better at resisting water, but not scratching.Best of both worlds: Do the primary coat or two with RP-342, let dry. Spray FF on select areas for even better protection.

I have been a fan of cosmoline for the past 30 years. As a young man I would help a relative prepare surplus military jeeps for sale. These things were covered in cosmoline in and out. My relative would pull them out of the freight container and some would sit for months of years before being put in doors (ohio winters). Zero rust… we would clean the interior of the jeeps and outer surface with a heated pressure washer, it took forever to clean this stuff off the exterior of the jeeps. I have his farm Jeep that sat outside on grass, topless for 30 years, it is still rust free. Not bad for a 1952. I attribute this to the cosmoline covering everything inside and under the Jeep. Yes I’m the summer it will drip on my drive and when it’s warm I smell like a crayola crayon but I have put this stuff on every vehicle I own. I have yet to have a rust issue.

I have used this product before. It worked then as I am positive it will again. I still have some things that I used this on from years back, so I know it works.

we ship machinery in a weather types and this product protects the bare metal areas

Amazing product very happy with it. highly recommend it for trucks.