Question 1

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?

Accepted Answer

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.

Question 2

Can this be applies over gas metal pipes?

Accepted Answer

yes but your pipes will be sticky forever

Question 3

Can this be applied over rust-oleum automotive rust reformer or vht rust converter?

Accepted Answer

Yes, RP-342 can be applied over any DRY surface (not oily or greasy) to ensure the best possible adhesion.

Question 4

Is Spray can compatible with wands for spraying inside rockers?  cap male or female  - tube on cap or tube on can?

Accepted Answer

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!

ASIN	B0888PB5G7
ASIN	B0888PB5G7
Age Range Description	Adult
Brand Name	BUTO
Color	Black
Container Type	Can
Date First Available	24 June 2025
Finish Type	Gloss
Indoor Outdoor Usage	Outdoor
Item Form	Aerosol
Item model number	RP-342
Manufacturer	Flywheel Distribution, LLC
Manufacturer	Flywheel Distribution, LLC
Model Name	RP-342
Model Number	RP-342
Paint Type	Spray
Part Number	342-1032-6
Product Dimensions	13 x 16.2 x 25 cm; 3.18 kg
Size	12 Ounce (Pack of 6)
Special Features	Washable
Specific Uses For Product	Vehicle Undercoating, Car Undercoat, Truck Undercoating, Rust Prevention, Rust Preventive
Surface Recommendation	Metal
Unit Count	72 Grams

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

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