Rust protection

I have an older 4wd Toyota truck that I love. I bought it on the west coast and despite its age it was nearly rust free. Now after 2 winters in upstate NY it is starting to develop surface rust on the body, undercarriage and drive train. Clearly older alloys are more susceptible to rust damage. I really want to keep this vehicle for some time and am willing to spend some money to arrest/prevent deterioration.

What types of products are best for protecting the vehicle? Particularly I’m concerned with the wheel wells, lower parts of the body, axles, crossmembers, transmissions, etc. I was thinking about some sort of spray-on bedliner type material applied after sanding off any surface rust.

What products are least environmentally hazardous?

I have gotten a wide range of advice, from spraying the truck bottom with diesel fuel, to black paint. Obviously this project will take some time and be a lot of uncomfortable work so I would like a more permanent solution that will last several winters. Any advice would be appreciated. Thanks.

I’m afraid you’re a little too late. If you see rust anywhere outside of the body, that’s only 30% of the rust that’s actually there. So there’s no product that can permimently stop rust. The proper way to fix rust on a body is to cut out the rusted section and weld in a repair panel.

Once rust takes hold, it’s hard to stop.


Yes, exactly. Once rust starts it cannot be stopped. You can try sanding, of course, and then try any of the spray products available at any auto parts store. You may at least slow down the spread and get a few extra years out of your Toyota.


For what it’s worth, some people like using a spray Loctite product called Extend Rust Converter (neutralizer). I have used it, but never went back and checked long term results. I would be careful using it near painted body surfaces. It’s to use on rust. Read the directions carefully. A hardware or maybe an auto parts store should have it.

Here’s a link to click:

Good Luck!

I have used rotating wire brush attached to a power drill before with good success. I grinded out the rust until I only saw clean steel. Then primed and painted the spots. Rust has not come back or if so it has been severely retarded. Plus, I do not know if the technique you are talking about would be well-suited for structural elements like the vehicle’s frame. At-least not from a cost stand-point. Do you not think that a thick coat of a petroleum based product would at least diminish oxygen and moisture contact with the steel?

Don’t worry about the frame. That’s made of a thicker metal than the body. Worry about the body.

Sure! You can stop rust if you can seal the metal from the air. But how do you get into all the pockets of the body to back spray these rust infected areas? You have to cut the rusted metal out to see what’s happening behind it.


thanks common sense answer,
I will give it a try. I feel that a combination of physical removal and chemical neutralizer such as this should be pretty successful if temporary. What techniques do professional car restoration folks use other than “cut and weld”?

Also, what do you guys think about undercoating, again to prevent/slow further rust damage?

You’re welcome !

“Rustproofing” and “undercoating” generally aren’t worth the effort, and in many cases can trap moisture against the steel and promote rust. It’s also easy to clog drain holes. Don’t bother.

Light surface rust on heavy structural members is usually harmless. As mentioned before, worry about rust on thin sheet metal.

Professional restoration people use cut and weld to remove rust. And to make sure it doesn’t come back.