Under carriage undercoating?

I had a friend that told me if I mix diesel fuel and transmission fluid that I can use that to coat my undercarriage, is anyone knowledgeable and has ever done this before? I heard the diesel fuel can eat away the costing that's already on the frame input please!!

 

sounds like a bad idea to me. Diesel not only corrosive. It's flammable. Why not use cosmoline instead? or fluid film?

 

+1 Fluid Film

 

There are companies that make good products exactly for this, for not very much money.

 

Wouldn’t diesel fluid and hydraulic fluid...catch on fire? Lol.

fluid film is good. Although I don’t know the durability. I just do a rubberized undercoat and make sure to check it periodically for any chipping. I know rubberized undercoat gets a bad rep but I think it’s due to improper care/application rather than it rotting from inside out. In theory if it’s applied to a dry, clear surface it shouldn’t rot from inside out.

 

LMFAO

 

Diesel and ATF are extremely flammable and that sounds extremely dangerous considering the amount of heat the engine and exhaust put out. Use fluid film or a specific product designed for undercarriage coating.

 

Cosmoline ftw

 

Bit of an over statement there, diesel is quite difficult to light off under normal circumstances - you can easily extinguish an entire lite book of matches in a bucket of diesel.

 

Cosmoline

 

Diesel is not flammable... its combustable though. Either way probably not the best idea.

 

It’s preventive, once you see rust light a match.

 

Unpopular opinion on here, but I second the rubberized coating. My brother is a lead mechanic over a large fleet of regulated vehicles. Several years ago, they started having frame rust problems with one of the vehicle manufacturers, so the entity my brother works for started coating the undercarriages of new vehicles with a rubberized coating. He said it drastically reduced the number of rust repairs they were having to perform. Good enough for me. Took my truck to Ziebart and will keep up with the yearly service, which I set up to be performed before each winter.

 

I use Fluid Film. Apply it a couple times a year. It’s been holding up ok in the NY salt. After 3 years the frame of my truck still looks new.

 

I just purchased crc 060260. I have watched at least 100 videos. Here and elsewhere. As stated above rubberized holds in water but if you keep at it might work. Fluid film is one which was compared. Do as you like but not diesel and atf. Good luck

 

Undercoating gets a bad wrap because everyone likes to post that 1 video of the guy pulling rust chunks off a coated frame... but they fail to realize that frame was rusty before it was coated.
Undercoating your truck is perfectly fine, infact im going to be undercoating the whole underside of my cab this summer (not doing frame since I already flooded the whole thing with cavity wax) Undercoating the cab will also help with road noise inside of the truck.

 

I did the cab too for the road noise.

 

Diesel in vapor form is extremely flammable. In liquid form, yes, not as flammable, but definitely not smart to spray all over the undercarriage of your truck. As far as dumping a matchbook into a bucket of diesel, keep fuels and ignition sources separate.

 

I would not worry about your truck bursting into flames if you went that route, but diesel and ATF are very thin compared to something like Fluid Film. I imagine that mixture would wash off quickly compared to FF which can last months before needing to be re-applied depending on the situation.

For what its worth Ive always heard of used ATF and diesel being used as a homemade PB blaster or penetrating oil, not as a rust preventative haha

 

Rubberized undercoating specifically is garbage. Same reason that line-x’ing a frame is a crap solution. You get coating defects and water skirts underneath. Some subpar wax coatings allow water ingress between the coat and frame also. A quality coat would make a barrier, which is why semi-fluid petroleum or lanolin coating work so well...