Rust Veto - 342 (Cosmoline) Undercoating

I've tried the fluid film thing. I guess it's OK for guys that keep a clean truck. One power wash after offroading in mud and it's gone.

Does cosmoline hold dirt/mud onto it? Or will pressure washing still take mud off?

 

Great post. Thank you for all of the pictures, commentary, and follow up.

 

Still holding up a year later?

 

We are in deep freeze for the season (-20 to -30c), so I haven’t crawled under the truck in a while. Will update closer to spring.

 

Well done sir!!
I only just found out about Rp-342, and so far I agree its a better fit for trucks that will see more dirt than most.
I unfortunately only found the rattle cans, fortunately I did get the black and absolutely dig it! But after reading this post I’gonna go bulk and try and save my slight rusty Taco.
It seems like you went above and well beyond on applying it everywhere. But either I missed it or didn’t see 2 areas that I have found to be problematic. The gas cap door hinge pin will seize then snap ( I have a spare to prove it ). The other area is all the bed Torques bolts, especially the 2 or 4 ( cant recall ) closet to the cab, they have a steel spacer sleeve that pretty much holds in water.
Thx for the post!

 

I’m sure the black cosmo would look great!

Correct, I didn’t do the fuel door hinges. Wasn’t aware they were an issue. That might be a better area for liquid lubrication vs Cosmoline.

Funny enough I just had the front bed bolts out as the bed mounts compressed slight causing a clunk (well documented issue in the 2nd gen section)






I’m sure I would have sprayed the bed bolt threads from the bottom, but I’ll definitely make sure it’s touched up. Pulling the bolts again and coating the sleeves wouldn’t hurt. Thanks!

 

Yup them plastic boxes were never a good idea. Mine compressed just after 60k km but still with in my extended warranty, Toyota wouldn’t do a thing even tho I could raise my box at the cab an inch or more. In the end I just replaced the box 2 years ago, and try not to over do it with loads. Hopefully theres a good remedy out there now for it!

 

When i sprayed my trucks chassis with cosmoline it appeared to have gone on thinner than some of the pics here. Didn't use the black, but regular amber. I was careful to stay away from any rubber, plastic or electrical parts of the undercarriage. From what was told to me by cosmoline it shouldn't be an issue, but to be safe your better to avoid coating them. Didn't coat anything with a hinge either...got oils for them when needed. I lightly coated the wheel for the spare tire and chain assembly after remembering how rusted they can get under there. As of 9 months, and a salty winter later the cosmoline still looks like i did last summer. Any dirt or salt just wash's right off it. If i did this with fluid film...you can bet there would be spots like the chassis welds with surface rust appearing this spring. Its turned out even better than i hoped.

 

If that's a statement from actual use then you didn't apply it good enough. 3 full salty winters. Used spray cans fluid film when I brought the truck home. Wool wax with pro gun following fall. Wool wax with pro gun and fluid film cans this past fall. Looks new under my truck. And I'm in Massachusetts salt capitol. You can rave about what you used but don't knock fluid film .

 

Well, i'm a couple miles from the border of ma. and ny in the nw corner of ct. Plenty of salt and brimed roads here. In fact theres piles of white salt still at every road intersection. Believe me i did a decent job every year with ff on my tundra. It still had the same frame after 19 years...rusty but all there. Imo, theres nothing wrong with ff, its just needs to be re-applied every fall but it wash's away by spring. Cosmoline is just so much less labor intensive. You put it on, its a done deal. I'll inspect the undercarriage well months from now hoping just a touchup or two, but right now all looks great.

 

Did you need to thin it out before spraying?

 

I didn’t, just ensured it was at room temp before I started.

 

CdnSldr- I saw your post on this Houghton 342 cosmoline coating and would like to know where you purchased it and how much the 5 gallon pail cost. I live in Nova Scotia. You did a great job on the application and photos. I have been doing my own undercoating for years and generally use Dominion Seal NO-Drip Undercoating. The cosmoline will not wash off, like most other undercoatings, but it looks like it ideally should be applied to a new vehicle. Does it creep enough that you can spray into the frame rails and doors? I use a Titan paint sprayer with Lemmer 45 degree high pressure wand (2000psi) to apply various undercoatings, including Canola Oil (believe it or not). The Canola Oil (Costco 18 litres for $22.00) seems to stick better than RustCheck or Krown. Look at Repair Geek YouTube for his undercoating tests. He found cosmoline very good also. wadepcyorke

 

My buddy had used fluid film on his 2019 trd, and a few months later sprayed it over with cosmoline rp-342....in short he ended up with a dripping mess. DO NOT USE COSMOLINE WITH THE FLUID FLILM, THEY DON'T MIX.
I use 6 cans of cosmoline rp-342 on my tacoma a year ago...still looks the same and didn't wash off like fluid film. Imo, if you don't like doing a job rustproofing over every year or sooner this stuff is best.

 

Oh, one other thing speaking with a cosmoline rep.....try to avoid any rubber, or plastic components. While they said its unlikely it'll do harm if used on a very warm day due to it quick drying properties, it can damage plastic or rubber if it doesn't dry quickly.

 

Lol duh.

Of course if you spray a liquid product on first, nothing else is going to bond. Seems like common sense to me.

 

So I’ve gotta know- how did it hold up through the long northern winter? Would you do anything differently? Do you have any current pics? thanks in advance!

 

Mine held up great. After 1 bad winter job i did a year ago looks as if just done. I have to drive on my 2 mile rudy dirt road year round to get to my home. At times the truck was really muddy for a few days unless hosed off. Didn't seem to affect the cosmoline like fluid film used on my old tundra in the past every year.

 

Thanks! Doing it to my 4runner when I get it all painted. I’m a belt and suspenders kinda guy apparently lol.