Cosmoline RP-342 Black Rust Preventive Spray (Military-Grade) 6-Cans

I wish it didn’t smell, but it is Cosmo. product works. Great coverage awesome!!!

This product is made of high quality and works great!

I wire brushed what I could, and applied over all surface rusted areas, and used woolwax with the pro gun to spray inside the frame rails and areas I couldn't get with these cans.The application process is messy for sure. Wear a cap, face shield, respirator, coveralls, and gloves if you don't wanna have it all over you. After it's cured, it isn't too messy to work on the vehicle. It drys to a hard waxy finish and will transfer a little bit if you rub against it, but nothing like grease. Doesn't smell much at all after a few days either. First couple days it had a typical waxy cosmoline smell. I would definitely recommend it for delaying corrosion. Since it's waxy, it won't flake off and trap water like paint can if it fails. I needed about 5 cans for my 04 Tacoma regular cab.

This stuff looks good and works well

Goes on smooth and easy, gets good coverage as I used about 3.5 cans on a truck. Remains slightly tacky even after drying.

Prep was the key to this working great. I used a steel brush and removes all the loose surface rust on my 2013 Chevy Tahoe. I then used a salt brine remover and cleaned the undercarriage twice with it to ensure I got all the salt off. I then sprayed a gallon of simple green degreaser (you can use any degreaser) and used a garden hose and sprayed it all of thoroughly and let it dry for 24 hours before applying Coroseal with a 1 gallon garden sprayer over the entire undercarriage with a nice even coat. I let it dry for another 24 hours then applied this black Cosomoline. It covers well and dries rather quick. I used all six cans to thoroughly and liberally coat the entire frame and various other high wear undercarriage areas. Be aware that even after it has “dried” it is still tacky/sticky as it is wax based but will not come off easily. I highly recommend this product but make sure you do your prep work.

The product is great works awesome looks nice but when you spray It leaks a lot out of the spray nozzle and makes a big mess. Need to get better spray nozzles

Great coverage for undercarriage, I was really impressed with how easy it was to apply. I would encourage anyone who uses this product, wear a long sleeve shirt and gloves.