Rust Veto - 342 (Cosmoline) Undercoating

Didn't ask at the dealer, was just wondering before I dive in, I'm a Fleet mechanic at a utility company and we use Fluid Film on the new trucks when they come in but I'm well aware of its shortcomings....I'm also aware dealers like to try to nullify warranties any way they can.

 

Salty water from the gulf is just as bad. This was after 2 trips to the beach on which my 2nd Gens frame came into contact with salt water. I wish I would’ve known about FF earlier. I know this may not seem all that rusty but for only being 2 day trips to the beach, the damage is quite potent.

 

I took my truck to the beach the very next day after I FF’ed the truck. Gave it some thorough rinsing to knock off as much sand as I could and now my frame is nice and matte. Dirt and grime don’t seem to stick onto the surface as bad as people say it does.


Edit: you can kinda see my rear differential and how nice it looks. I understand it’s new, but it it’s gotten pretty dirty after I drove my truck through streets flooded with muddy, murky water.

 

Thats exactly how my tundra looked after a 4 month winter being here in connecticut. I also wished i'd used fluid film from day one. The fluid film did slow the rusting process well, but it did get gradually worse every year after melting snow, and deep water puddles washed it off by spring. I didn't wait for winter with the new tacoma, using cosmoline this time to stop the washing off effect, which was the ticket to having a well coated frame year round. This stuff is not your crappy undercoating that traps moisture that ends up destroying a steel chassis. I go to long island on fishing trips with the boat....its trailer was getting some rust from the salt water to. I hit it with a can of cosmoline pretty good in the leaf spring/axle area. Well see how that goes after a year...so far so good.

 

Looks like a decent deal on those cans straight from Cosmoline

SPECIAL ONLINE PRICING (reflects 27% discount)::

• 1-Can (1 Aerosol Can): $17.50
• 3-Pack (3 Aerosol Cans): $38.00
• 6-Pack (6 Aerosol Cans): $72.00
• 9-Pack (9 Aerosol Cans): $99.00

https://www.cosmolinedirect.com/cos...wi6uTmAFbrfSKBTYtKnJXmqrL9E5ncIBoC6o0QAvD_BwE

Mine is just a lease but given my experience with Toyotas I was going to grab a few cans of Fluid Film and just hit the most obvious rust-prone areas, plus some key bolts and things (for future maintenance, someone down the line will silently thank me). I think I'll use the Cosmoline instead as it sounds like it will last a lot longer.

 

Unless your driving off-road a lot scraping the chassis with stones and logs, cosmoline won't come off that easily. I drove my truck though a bunch of harder packed snowbanks last winter...it didn't seem to affect the cosmoline coating a bit.

 

Do you guys think applying cosmoline over bar chain oil/paraffin mix would work?

I undercoated my truck with a mixture of 3/4 bar chain oil and 1/4 paraffin wax about 4 years ago. It worked great and stopped the rust dead in its track. However, the film coat is getting thin now, maybe because this waxoil mixture collected soot dust over time.

I want to switch to cosmoline, but cleaning the waxoil before application would be near impossible. Any idea what happens if cosmoline goes over waxoil ?

 

I think you are asking a question that very few will have an answer to. My suggestion, TRY IT! On a readily visible area (frame rail) and see. \

If it looks good after a week, Do the entire truck!

Tell us all what you find out!

Mix and match is likely OK for almost any surface where the original coating has been depleted. Maybe not so much for the protected areas.

If it looks good, it probably is good!

ETA

I just ordered a case of the P-B Blaster surface shield from Home Depot.
about $10 a can.

I'll give it a try on the bumper and tailgate. ;-)

 

I just had my Taco Krown treated. At my age cannot lay underneath a vehicle to spray that shit on and get it all over me. Krown is done and I am happy and clean. Just saying

 

Hay!, I'm 70 and was able to spray undercoat my truck. How old do I need to be before it's "Your too OLD!" ;-)

 

70

 

So I’m in RI and just like many of you salt is liberally used in the roads I travel daily. Unfortunately I’ve never protected my Tacoma I try to keep her as clean as possible but regardless of efforts I know what’s happening under there.

With that being said, after a good power wash what would be the next step, apply the cosmoline directly to clean metal or should I do something to any areas that have begun to rust?

 

Don't apply cosmoline over any petro base rust inhibitor or even fluid flim for that matter. You will end up with a dripping mess as my buddy did doing a similar thing. You'll probably need to power wash everything well first to coated with cosmoline.

 

Wire brush any surface rust away best as possible, the apply rustoleum rust inhibitor, and wait till it drys. You can the apply the cosmoline. I got sick of applying fluid flim every year, only the see it wash off by spring with surface rust begining to show. This RP-342 cosmoline stuff works unreal, going on my 2nd winter here in connecticut after cosmolining my trucks chassis. Inspected it well this summer and it still looks like it was just done. Probably be that way for years with a minor touchup or two.

 

That’s great! Thanks! Now just gotta find the time and it’s getting cold.

 

Mid summer is best outside for the cosmoline...stuff likes to be sprayed on in 90 degree heat.....less dripping in the long run

 

Looks like I’ll be holding off until then. Thanks zoo truck again

 

I’m 99% sure that Cosmoline won’t stick to anything “oily”. By “oily” I don’t necessarily mean a petroleum product, I just mean something wet and gooey.

I seem to recall a thread where a dude tried Cosmoline over a typical wet undercoating. I think it just sorta streaked and didn’t set up properly.

You’re probably best off sticking to what you first used.

 

If you’ve already got rust starting, personally I’d recommend a more traditional undercoating. Something that will flow and creep to the rusty areas that are not visible.

 

What if a did a cosmoline coat for the gross amount and something with a little more flow/creep to it for detail after the cosmoline set up? Obviously all would be after cleaning and knocking down the surface rust that’s begun.