This might just be a dumb question but..

[Fieldtester96]

If i were to take the used motor oil i get when i change the oil, heat it up and spray the undercarriage in places where it usually doesn't get any oil spray. Would that help with corrosion prevention. I know i should go ahead and just paint everything but i dont want to do that until i have the time to properly prep the surfaces. Also it seems like the front end is rather rust free due to oil on literally everything, so maybe it would help out the back end. What do you guys think?

 

[OSS]

Heating up used motor oil (on the kitchen stove?) or anywhere has got to be up there with taking a hike through a SuperFund site.

Yes an oily coating will slow down the rusting, but don't be so cheap trying to use used motor oil. Get something specific for that purpose. Corrosion-X, boiled linseed oil, HinderRust, NEW motor oil - but don't use USED motor oil. Super toxic.
But if you really are planning on painting one day - don't use oil . You'll never be able to fully get it off and the paint won't stick to it well. Use linseed oil instead. It eventually polymerizes to a flexible rubbery coating. Not oily at all

 

[Fieldtester96]

Heating up used motor oil (on the kitchen stove?) or anywhere has got to be up there with taking a hike through a SuperFund site.

Yes an oily coating will slow down the rusting, but don't be so cheap trying to use used motor oil. Get something specific for that purpose. Corrosion-X, boiled linseed oil, HinderRust, NEW motor oil - but don't use USED motor oil. Super toxic.
But if you really are planning on painting one day - don't use oil . You'll never be able to fully get it off and the paint won't stick to it well. Use linseed oil instead. It eventually polymerizes to a flexible rubbery coating. Not oily at all

Most likely im going to have to patch work on the rear frame when i paint. So i dont have any problem spending the time to de-grease everything. Also wouldn't used motor oil be better than new? The higher carbon content would provide for a stronger bond with the metal than the carbon content of un-used motor oil?. Again i dont know much i just wanted more or less a proof of concept.

Also i planed to use the heating element out of an old deep fryer to heat it up. then put it in an old bed liner spray gun then coat the underside.

 

[SteveH]

Motor oil makes an ok rustproofing compound, but there are other ways to do this.

Most motor oil (new or used) isn't viscous enough to require heating. Personally, I would buy several cans of Fluid Film at Lowes and use that. Fluid Film does not dry (critical) and is viscous enough to last. Can be wiped off for resto purposes. The aerosol cans go a long way. If you want a creepy oil to get into frame seams, thin 90wt gear oil with some solvent and pour it in. The solvent evaporates and leaves the 90wt behind.

In Michigan, we mixed 90wt gear oil and roofing cement (the gallon can of runny stuff) and sprayed that on the bottom of a Toyota motor home. It never hardened and made a decent rustproofing. Very messy to apply! You can also make rustproofing from ATF and paraffin, heated, and spray or brush that on. Then drive down a few dusty roads.

Just don't ever apply 'spray tar' (hardening) to a rusty surface. When water gets underneath it (and it will) it traps in the water and salt and accelerates rust. The only place I used spray tar was on the backside of the lower portion of the front fenders on my FJ40 to prevent thrown rocks from denting the fenders.

 

[Fieldtester96]

Motor oil makes an ok rustproofing compound, but there are other ways to do this.

Most motor oil (new or used) isn't viscous enough to require heating. Personally, I would buy several cans of Fluid Film at Lowes and use that. Fluid Film does not dry (critical) and is viscous enough to last. Can be wiped off for resto purposes. The aerosol cans go a long way. If you want a creepy oil to get into frame seams, thin 90wt gear oil with some solvent and pour it in. The solvent evaporates and leaves the 90wt behind.

In Michigan, we mixed 90wt gear oil and roofing cement (the gallon can of runny stuff) and sprayed that on the bottom of a Toyota motor home. It never hardened and made a decent rustproofing. Very messy to apply! You can also make rustproofing from ATF and paraffin, heated, and spray or brush that on. Then drive down a few dusty roads.

Just don't ever apply 'spray tar' (hardening) to a rusty surface. When water gets underneath it (and it will) it traps in the water and salt and accelerates rust. The only place I used spray tar was on the backside of the lower portion of the front fenders on my FJ40 to prevent thrown rocks from denting the fenders.

That was extremely informative, i think ill go with the gear oil treatment. Thanks SteveH

 

[MarkBC]

It isn't environmentally friendly but it will work. Drive down a dusty road after application. Wd40 also works this way too believe it or not

 

[Cruzerman]

I can say that on the 80s forum, they talk about two products : fluid film and woolwax. Both get good reviews but I have no first hand experience with either.

 

[YooperCruiser]

I've been oil spraying my trucks for decades, gear oil works great because it sticks so well, so does chainsaw bar oil, the winter blend is easier to spray, and yes I've heated oil many many times it's not a big deal unless you're really stupid about it. This year I bought a 5 gallon pale of NH Oil undercoating and I"ll be using this from now on. Spraying my Tundra and my wifes Tacoma tomorrow.

 

[Fieldtester96]

I've been oil spraying my trucks for decades, gear oil works great because it sticks so well, so does chainsaw bar oil, the winter blend is easier to spray, and yes I've heated oil many many times it's not a big deal unless you're really stupid about it. This year I bought a 5 gallon pale of NH Oil undercoating and I"ll be using this from now on. Spraying my Tundra and my wifes Tacoma tomorrow.

What do you use to spray the oil on?

 

[YooperCruiser]

What do you use to spray the oil on?

For gear, bar or motor oil I use a schutz gun. I now have a nice oil spraying gun I got from NH Oil and it has different wands to get inside frames and get to places you can't shoot direct. It's a real nice setup.

 

[macdaddy59]

I buy fluid film by the 5 gallon bucket and coat all of my trailers and undersides of the vehicles. I also use it on most repair work and especially on bolts or threads.

 

[Shes Mad]

I buy fluid film by the 5 gallon bucket and coat all of my trailers and undersides of the vehicles. I also use it on most repair work and especially on bolts or threads.

I do the same thing

 

[cruisedeisel]

Keep her lubricated! Used atf/old diesel/ used engine oil. Free is always cheaper.

 

[NookShneer]

Paging @Kleatus for all the best rust prevention you could ever need.