WD-40 as rust-prevention? (5 Viewers)

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Any downside to spraying the axle housings, frame rails, control arms, radius arms and pretty much the underside of the truck as a form of rust-prevention?
What say the MUD community?

PS- I did search, and found a few obscure posts of some members doing this but wanted to hear some more weigh-ins.
 
Any downside to spraying the axle housings, frame rails, control arms, radius arms and pretty much the underside of the truck as a form of rust-prevention?
What say the MUD community?

PS- I did search, and found a few obscure posts of some members doing this but wanted to hear some more weigh-ins.
I would not use WD -40, but I would use Fluid Film or WoolWax.

You can get Fluid Film in a spray can either online or at O'Reilly's or Menard's.

WD-40 is actually a water based product and will wash off.
 
WD-40 is actually a water based product and will wash off.
It may or may not wash off, but it is not a water based product. WD-40 - Wikipedia

Interestingly, per the above link it 'was originally designed to be used ... to protect the outer skin of the Atlas missile from rust and corrosion.'
 
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I say send it!!!!!! It would certainly be better than nothing
 
Any concern with it penetrating threads and causing a nut to break lose?
 
Grease works really well, though it's messy. I'm sure Fluid Film or Wool Wax are more sensible options.

Oil leaks can definitely help preserve undercarriages, if in the right spots. If you're already working on a vehicle that has rust, adding grease to threads and smearing on spots where the paint is wearing thin isn't a bad idea. But it's not the ideal fix of course. I can't imagine WD-40 or anything similar making bolts just fall off, unless they were already too loose.
 
As others said, use fluid film or woolwax. PB blaster surface shield is also excellent - think that's what I'll use next time I do a treatment this spring.
 
Any downside to spraying the axle housings, frame rails, control arms, radius arms and pretty much the underside of the truck as a form of rust-prevention?
What say the MUD community?

PS- I did search, and found a few obscure posts of some members doing this but wanted to hear some more weigh-ins.
I say it’s fine, but you would have to reapply somewhat often. The “WD” stands for “water displacement”.
 
Used ATF and candle wax; best multipurpose do-it-yourself brew in the shop.
 
I covered some rotors and hubs of an exposed axle with wd-40 and it did not work. Solid surface rusting all over raw metal in just a few months and I applied it 3-4 times.
 
Any downside to spraying the axle housings, frame rails, control arms, radius arms and pretty much the underside of the truck as a form of rust-prevention?
What say the MUD community?

PS- I did search, and found a few obscure posts of some members doing this but wanted to hear some more weigh-ins.
Why would you not use a product that is designed to do what you want it to do?
I spray Fluid Film from tip to tail every October and daily drive in the northeast. Woolwax works well too.
 
I would personally prefer to use a non-toxic, or less toxic thing if I was spraying the whole undercarriage deliberately and not merely spreading some grease around on a truck that's already leaking oil.

From what I've heard, Wool Wax and Fluid Film are supposedly non-toxic. I don't think the same can be said about ATF mixtures.
 
WD40 is terrible at preventing rust.

Before my machine shop was heated in the winter it was very troublesome to deal with large temp swings from cold to warm. A couple million lbs of iron doesn't warm up very quick. The cold iron would condense the moisture from the warm air. I tried hosing things with WD40 a couple times. It never worked at all. Rust almost seemed worse after WD40. It was like the WD40 instantly emulsified with the water droplets. Made a real mess.

Light hydraulic oil like ISO 32 in a weed sprayer works OK. ATF would do the same thing, but it's red and more expensive.

To clean the oil off I used diesel fuel in a weed sprayer and some rags.
 
WD stands for Water Displacement. While the stuff will displace water and initially protect steel, eventually (in short order) its no better or even worse than using nothing.
My experience with it is that it eventually attracts rust.
My advice is don’t use it for undercarriage rust protection (it has a gawdawful odor anyway). It won’t work.

There’s plenty of other choices that do work.
Look into linseed oil. That stuff definitely works. I used it for 30 years.

 
I use linseed oil mixed 50/50 with mineral spirits to seal the deck on my trailer. I apply every year at the beginning of the summer. After I read the above post I went to look at it and the bolts that hold the wood down are surprisingly rust free after 3 years (last time I replaced the deck) sitting outside. Might be a good choice.
 
Great discussion and great suggestions! I have linseed oil lying around from when I used to finish axe handles. Also like that it is non toxic.
 
Any downside to spraying the axle housings, frame rails, control arms, radius arms and pretty much the underside of the truck as a form of rust-prevention?
What say the MUD community?

PS- I did search, and found a few obscure posts of some members doing this but wanted to hear some more weigh-ins.
So you live in San Diego California, last time I recall is you have no real rust issues there, ( Born and raised 1963-2003) so I would not worry
 

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