Rust Veto - 342 (Cosmoline) Undercoating

All i can say after using fluid film for years and now cosmoline for the 1st time starting with clean no rusty frames....the cosmoline one looks awesome. It sure stinks bad if you get overspray on the exhaust. I did my truck on a 90 degree plus hot day, but i'm pretty confident it creeped into most places that needed it before it setup, and dried. Biggest pita was all the prep work getting the truck fully ready to spray this stuff on vs my tundra that was more open to service.

 

I was surprised how easy cosmoline wipes off with a rag using mineral spirits or even acetone. Soap and water?...lol. Pretty sure it was cosmoline they coated my brothers 400 trans am with back in the 70's...that car is still perfect like just came from the showroom. I always told myself if i ever find out what that dealer used i'd do the same on a new truck.

 

I actually don’t mind the smell of Cosmoline burning off. It’s subtle enough that it doesn’t bother me. I didn’t mask off anything either, so there was a decent amount to burn off.

 

Lost my beloved 2003 Taco to frame rust. Hope to not let that happen to my new one. My gallon of Cosmoline arrived today and applied it by hand to where the 2003 rusted.
4-inch foamie and a chip brush seemed like the best applicators.

This is all I used.

 

Excellent post!
I just finished undercoating my truck with the rp-342 black spray cans, couldn't properly do the inside of frame rails however.
How did you yours sprayed ? Did you use some special hose for inside of frame rails ?

Thanks

 

Post up some picks! Would like to see more of the “black”.

I used the wool wax “Pro” stray gun kit. It included 2 wands, one with nozzles 360*. It worked “ok”.

 

I just pulled what frame rubber plugs their were, and sprayed it in there using the red straws provided. There were several other holes in the frame to use also. Ended up using a complete can between both sides. All in all i felt pretty confident i did a decent job for now.

 

Thanks for sharing!

 

Thanks for sharing fellas! I just did a quick spray this year, used 5 cans of the black stuff. next year i gotta properly coat inside of the frame and touch up whatever i missed.
In the past i used numerous coatings on different vehicles, krown, (rubberized and asphalt coatings, rust check - everything available from canadian tire), crc marine corrosion inhibitor (similar to rp-342, also good stuff but difficult to find in toronto) and so far rp-342 seems like its the best fit for me since i dont want to respray every year but can just touch up and its dry to the touch unlike fluid film or wool wax.
Toyota canada offers rust proofing with some kind of similar product, it looks exactly like rp-342 when sprayed, they guarantee 10 years no rust after initial application and touch ups by them every 2 years (cost around 20$). This service from them costs 1000$ cad + tax. So just buying some rp-342 is a much cheaper solution.
I am happy that i used a full body painting suit (alternatively you can use some old clothes) and a full face organic respirator. Having done similar things in the past (rubberized and asphalt coatings) i remember coughing my lungs out for next few days when doing it without the respirator. Having covered open skin saved alot of time on cleanup as well, otherwise be prepared to be washing it off with a bucket of acetone.

For the wool wax nozzles, do you know the diameter of them ? do they easily fit into the frame openings ?

fyi, i own 4runner no tacoma

 

It’s unfortunate that rust never sleeps. The auto manufacturers don’t seem to mind though

 

Auto manufacturers are in the business of making money, can't blame them, its the owners interest to keep their vehicle for as long as they can.

 

Is it okay to apply cosmoline on top of rubberized coating?

 

I don’t see why it would be a problem. If water gets behind the rubberized coating, it will still cause problems. Just be thorough in the application, and put it on thicker.

 

I would think a thinner product like the red rust check would be best for doing the interior of body panels. Like the inner and outter rockers, front fenders and bed sides. Also that black stuff in the pictures of the 4runner looks great until you realize it completely rotted out behind that pretty black coating. For high wear areas that Cosmoline stuff looks great. My $0.02

 

“That black stuff” on the 4runner is Cosmoline FYI

 

I don't know which solvent cosmoline has in it, but if it's not alcohol or toluene you should look into its compatibility with plastics and rubber. Some stuff, like MEK and other ketones can destroy/melt some plastics in seconds and swell rubber while also making it very easy to cut/tear. Probably the product manufacturer will put a warning label on the container if it's that aggressive towards plastics.

 

it looks dried out to me. I know in the past the rust proofing with the black dye or colour in it tended to dry out and crack/flake off. Maybe this stuff is different, time will tell I guess

 

You must not be very familiar with Cosmoline. It all “dries” to a matte finish. Be it a golden translucent colour (the original stuff) or tinted black like you see above.

 

so does this stuff remain soft if you take something like a screwdriver and scrape it? Or does it dry all the way through where it meets the metal you’re trying to protect?

 

It remains “waxy” and firm. I can scrape it with my fingernail.