Rust Veto - 342 (Cosmoline) Undercoating

Well after tons of research I decided on Rust Veto 342 for the undercoating on my soon to arrive TRD Pro. I went ahead and ordered a 5gal pale and the fluid film spray gun. Should last me for the next 10 years.



From my research, rust veto can be sprayed with the fluid film gun. Worst case, if it is too thick, it can be cut with any solvent. I know lots of folks have use the canned version of RP-342 with great results, but I haven’t see too many folks spray the bulk stuff with an undercoating gun.




Before anyone suggests FF, I did consider it, and will possibly use it in a few key areas where the creeping properties are necessary; but in general I wanted a waxy coating, not oily. Plus in high splash zones and areas seeing lots of water, a waxy product will hold up much better.

Similar cosmoline based product that have tested very well in various online tests include LPS 3 and CRC Heavy Duty Corrosion Inhibitor.

Does anyone have experience spraying a cosmoline product with an undercoating gun that could offer some advice?

 

Have you ever used cosmoline before? It’s not that waxy and it’s pretty nasty stuff. The only reason to use cosmoline is if you intend to store your truck in a WWII bunker for the next 70 years and don’t plan on using it.

I’ve cleaned up enough cosmoline to hate it.

 

Thats some serious rust prevention coating. Make sure to post some photos once you have completed spraying the undercarriage.

 

I'll never order post war surplus Mausers again.. Cosmoline is nasty stuff!

 

Likewise, I’ve cleaned it off plenty of new vehicle parts and firearms. (Army mechanic for 12 years)

That is actually one of the exact reasons why I chose it. It’s proven and doesn’t come off very easy, plus will stay much cleaner than FF type products.

Comes off easy enough with solvents.

 

Solvent bath.

 

And if no solvent is on hand..

Small parts - boil on the sink.
Long guns - boil in the park tank.
20 minutes usually does the trick for even heavy cosmo.

I'd be all about this if I lived where protection was necessary.
Post up your experience and results.

 

https://youtu.be/mbXBax-Kh9E

This guys been documenting his undercoating journey using FF. He’s also got a great review of various products on his channel.

check out 1:30 of the video above...talks about the rust on the front of the rear axle. FF being washed away from water.

 

I use transmission fluid. Works perfect !

 

Old farmers trick and super cheap! Some farmers mix the tranny fluid with a small amount melted paraffin wax before spraying it on their farm machinery before being parked for the winter.

 

Yup I'm with ya man. If I lived in the rust belt, I'd totally go that route. Maybe not 5gal worth, but I'm contemplating RP-342 for even AZ

 

The 5gal pale was by far the most economical. I do plan on re spraying once a year, or earlier if needed.

My fiancé is due for a new vehicle soon, so I’ll spray that one too. Can probably make a few bucks back spraying friends and families vehicles as well.

 

Good choice, Fluid Film sucks. I don't know why anyone would ever want to deal with have oily/greasy shit all on the bottom of the truck. I spray my first gen with fluid film and it was miserable to work on.

Don't forget to spray the internal cavities these trucks rust from the inside out

 

Absolutely agree with all of this!

While fluid film and other oily/wet coatings work well, the other waxy based coating work just as well and better in high water/snow exposure areas.

I’ll be removing the fender flares for PPF, and whatever else he wants, based off how much coverage i want. I’ll be leaving the flares off for rust proofing, as well as removing the headlights, taillights, front bumper,and tail gate skin to spray as many crevasses as possible.

I recently had the front bumper off my fiancé’s 2014 Mazda CX-5...was really surprised to see how much rust was appearing on the factory color painted sheet metal behind the bumper. This area had never been exposed directly to any elements, no rock chips etc.

That being said, I’ll be going hog wild with this undercoating gun.

 

You should take the rear bumper off (and apart) on the Tacoma. Lots of layers of sheet metal and plastic that are guaranteed to trap water and rust out in no time.

 

lol...so many here swear by it above anything else.

 

This stuff is great....every 911 since 1968 came right off the Porsche production line with Cosmoline.

There is good news and OK news however.....the good news is that rusting is completely eliminated....the OK news is that it looks ugly after a while, especially on areas that heat cycle, like the underside of the engine and trans.

 

Got the majority of the undercoating done over the past day and a half. I will revisit this in the spring to pull the front bumper and get inside the door panels.

And now for pics, lots of pics!

Definitely over sprayed several areas as I was getting the equipment figured out.


Some factory undercoating (consistency resembles silicone) plus CRC
Before








After









As many body plugs pulled as I could find