RP-342 cosmoline.

I use to use fluid flim on my tundra, living in connecticut...right in the center of the salt belt. I got tired of doing it every fall, only to see it washed away by late march with areas on the frame starting to show surface rust. I did this tacoma when new using cosmoline rp-342. No more every year doing the job over. I guess if you live in drier parts of the country, fluid film is ok, but it gets way too wet up here.

 

With it being summertime I'm checking on my existing cosmoline application. Overall seems pretty good after one season. I found a few light areas that have some orange dusting that I plan to lay more RP-342 into. It's a few bracket areas and a couple seams. Probably missed in the first go this winter.

Question for you guys. After I clean the underbody, should I use any iron/rust converter to hit those flash rust spots before more cosmoline on top?

 

When I noticed a couple orange spots on the rear leafs inside the rear wheel wells a year later, I just hit them with 2 coats of cosmoline. Idk, if I totally sprayed them good initially, but it s been 2 years since, and I can't find anything else I missed. This stuff is permanent. I can do other things like worry when should I change my oil next.

 

Yea my initial application was mostly good, but it was middle of winter in my garage before snow/salt hit. Needed to get the majority done but missed some various small spots.

 

I would say yes, or at least that’s what I do

 

How are you guys protecting the internal parts of the frame where you need a long application house to get it covered? It seems like those areas are most prone to road salt/chemicals getting stuck and rotting without showing until it’s too late.

 

it has some corrosion protection from the factory on the inside

 

I did't pop off the plastic covers to go into the transmission boxes yet, but usually, the straws shooting at it works well. You can also get like 3-foot-long universal spray straws to cut to length to get deeper inside.

 

I coated mine with the rp-342 around this time last year with 5k miles on the truck and played in the snow a fair bit this past winter including pushing through drifts that were taller than the frame. I put an extra coat on the bottom rails and the back side of the rockers for the initial application because of the bi-annual chip-n-seal of the roads in my area. I also applied it heavy on service points like shock mount/suspension bolts and nuts, etc.

15k miles later and no signs of rust or bare spots. It's dusty looking with a lite-brown tint from a few wet camping trails, but it's holding up very well. May get under it this weekend and get some photos. Deciding if a drain and fill on the trany is worth it at 20k miles.

I also covered the fill and drain plugs well on 1st application. When I did drain and fill both diff's at 15k miles, all the plugs came out with zero fuss vs. some of the crusty / frozen diff and transfer case plug stories I've read on the forum. After I was done and wiped off the drips, I put a fresh coat of the rp-342 back over to seal them again. The oil and well as mineral spirits does cut the rp-342 quickly if you need to remove it.

 

If you are using rattle cans, you need an extension like this:

$17 DU-MOST Aerosol Can Extension Kit, 24" Flexible PVC Hose, 360-Degree Brass Nozzle, Reusable & Fits Fluid Film Rust & Corrosion Protection Cans, Clear

https://www.amazon.com/DU-MOST-Extension-360-Degree-Corrosion-Protection/dp/B0BRJNFDR8

I flush mine out after use by spraying some WD40 through it so it doesn't get gummed up from the rustproofing product.

I would also suggest doing a test spray into a clear plastic soda bottle to assess the coverage that you are getting.

 

I could be wrong, but that extension will not adapt to the rp-342 cosmoline rattle cans if used. They have an odd nozzle. Years ago I found one to fit from eBay, it arrived with no visible brand name packaged in a plastic bag like someone had specifically made them just to fit their cans. I can't even recall the seller.

 

Some cans require a male to female "graffiti adaptor".

$22 The UPROK Female Adapter and Male Caps Pack (22pc) for Krylon, Rust-Oleum, American Accents, and More! Spray Paint Caps for Home Improvement, Spray Paint Art, Street Art Tips

https://www.amazon.com/Adapter-Rust...335-47d0-a873-65d4ea6c8a44&pd_rd_i=B07HRMWQ7D

 

Finally decided on which undercoating to put in the truck and was looking to do in the next few weeks. Just went to purchase some aerosol cans of this stuff but it's not even popping up on Amazon anymore. Cosmoline direct website showing backorder.
Have any of you purchased recently and if so where from? I'm willing to order from Cosmoline direct but fear it wouldn't show up until it's too late.

 

I saw the back order mention, it's like one week delay.

 

I did 90 percent of my frame with some loctite pc 9660 maxi coat the other day on my new truck that I had from work. It looks to be the same stuff, heavy amber colored wax coating. I ordered a few cans of heavy formula rp-342 and I still have a couple cans of loctite brand. Planning on finishing the job on my off days. I did my old colorado with fluid film regularly and it still rusted where it got blown off by slush and salt in winter. This seems like a much better solution to the rust problem we have with Canadian winters.

 

Got mine from Amazon

 

I bought a gallon of 342rp from Cosmoline Direct and used it on my brand new '23. Went on great and seems to be working as desired but it hasn't seen winter yet. Only issue I have with it is the price. I think living in Canada we get RAPED with exchange and charges. I paid $145 CAN with exchange for the Cosmoline, and FedEx charged me another $50 to ship it! Kinda pricey if you ask me. Anyways, I researched and found a company called Commercial Oil in Hamilton ON. Speaking with their sales guy and reviewing the few different undercoatings they offer, I'm heading there on Friday to pickup a 5 gal pail of Rust Preventative #1 for $200. As per the spec sheet it's a similar product to Cosmoline- an amber colored solvent cutback rust preventative. I hope that it is similar enough that there isn't any unwanted interactions between them. I'll report back my findings.

 

I purchased a pack of 9 cans off eBay when there was a fair deal that a seller had years ago where the price of the product plus shipping came out very close if buying direct. Haven't had any need to buy more. Buying direct, you'll find the overall cost as good as anywhere else.

 

Today, I added some of Commercial Oil's Rust Preventative #1 to some areas that we're not well covered by my Cosmoline job This stuff is a bit thicker than Cosmo, I had to thin it to spray out the siphon gun. I added varsol paint thinner as the freshly opened can had a distinct scent of it. I compared the dried product to cosmo and it is practically identical. Color, odor and consistency was so close you couldn't tell them apart. Where I oversprayed the cosmo with RP#1 there was no difference once it dried. If you're looking for a source of "cosmoline" in Canada for a way better price look up Commercial Oil in Hamilton. I have no affiliation with them, they just provided good service when I ordered and when I picked it up. I'll report back on this thread in the spring to say how well it held up to this winter's salt and brine.

 

Hi -- First post. I'm reading this cosmoline post with interest -- trying to fight off rust here in the Midwest. Are you guys spraying cosmoline on your suspension springs? Or are you using some other product on springs? Just wondering how the cosmoline holds up on the springs since they can obviously flex. Thanks!