Cosmoline RP-342 "Heavy" Rust Preventative Spray (Military-Grade) 24-Cans

This stuff is the best undercoat and rust preventative for autos. It coats and stays put, and doesn't wash off, unlike fluid film.Identical to CRC corrosion inhibitor, but can spray upside down and with the straw, unlike CRC.It does have 2 more ounces than the CRC, but its on the expensive side. Worth it to me cause it sprays better than others.

I knew going in this the product was 5/5 but the smell was its downfall. Good god does it smell. I turn the corner and can smell my truck 50 ft away. It's been about a week, I'm hoping it fades within a month. Also definitely cover the hot parts of your vehicle, with tin foil, otherwise it'll bake and smell worse. Hoping next season I'll do better at prep work and avoid overspray on the warmer components.

Cosmolene RP-342 has been effective in arresting and preventing rust on metal parts.

I used this as undercoating on my Escalade because the frames are wax dipped and mine was beginning to come off. I was beginning to get rust. This adheres very well and is sticky when sprayed. I have full faith that will stop the rust that has started. It’s not as affordable as fluid film but fully believe you get what you pay for. It dries almost clear so it won’t hide the rust but you’ll also know if it’s actually working. Wear gloves when applying!

The formulae is legendary. It stops time itself. Great prep for storing things long-term. If you have a tool that you don't want to take from the mothballs every six months, this is the product to use. In the WWII era, this product was known as "Cosmoline". It smells like canvas tents and howitzers.

Fantastic stuff. Amazon seller is fantastic really stands behind the customers.

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.

Awesome undercoating so far. Can look runny if applied heavy but it levels out nice and sticks great. I used 6 cans to do every square inch I could find on 2014 F-150 supercab. Living in Michigan is horrible on vehicles so I will update this after a our salt and brine filled frozen mitten thaws next spring.