undercoating for rust (1 Viewer)

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looking at a truck that has been in New Hampshire the majority of its life about 7 years. the owner had the dealership do an undercoating for rust prevention. He says the surface rust was sanded and then treated. it looks good almost a linex type coating. How will this do on slowing or stopping the rust?
 
As long as you remove (seal against) oxygen the rust cannot happen.

I recently "undercoated" my frame, after welding on my sliders, with the 3M spray on fender well rubber coating - no sanding just sprayed right over the little rust spots that were starting to show.
 
As long as you remove (seal against) oxygen the rust cannot happen.

I recently "undercoated" my frame, after welding on my sliders, with the 3M spray on fender well rubber coating - no sanding just sprayed right over the little rust spots that were starting to show.

That won't stop it from rusting from the inside out. That is the problems Toyota's have had over the years, Toyota uses a fully boxed frame instead of the traditional C-frame. What happens is mud and/or road gunk clogs up the drain holes in the frame. any moisture that gets up inside the frame can't get out, causing rust. I don't think I've ever seen a Toyota truck rust from the outside in. The undercoating certainly won't hurt anything though and it makes it look better
 
toyminator-

Good comments! :cheers:

I forgot about rusting from inside that boxed frame.

You are exactly correct, I was trying to convey similar info to help keep the frame from rusting from the outside in - there isn't much to do about rust from inside out.
YEP - rust preventative is better than letting it go and it looks nice too!
 
I just received the "it's not a recall but we'll fix or buy back your truck" notice from Toyota for this very problem. I'm in the desert so no problems here.
 
That won't stop it from rusting from the inside out. That is the problems Toyota's have had over the years, Toyota uses a fully boxed frame instead of the traditional C-frame. What happens is mud and/or road gunk clogs up the drain holes in the frame. any moisture that gets up inside the frame can't get out, causing rust. I don't think I've ever seen a Toyota truck rust from the outside in. The undercoating certainly won't hurt anything though and it makes it look better

Toyota Pick Up trucks had fully boxed frames. But Tacoma's (95+) all have a C-channel frame from the cab back. It still doesn't prevent rust. Just look at the thread about the Toyota buy backs on the earlier Tacoma's due to frame rust.

Anyway, you should prep the areas you spray, because moisture can also seep in through a poorly sprayed area and will build up rust. I've seen it on truck beds with a poorly sprayed bedliner.

I also live in a state that sprays salt like crazy during the winter time. I just make sure to spray out under the truck maybe once a week or so. Looks good so far.
 
Coating the outside is only part of the battle. As mentioned, they go from the inside out. You need to spray the inside of the frame with a wax or oil type substance, easy stuff to fog in there. All interior cavities and seams like this stuff too.
 
One trick that people use in the rust belt is to spray old motor oil inside the frame with a garden sprayer......spray it in all of the holes, trying to coat as much as possible. It's not the most eco friendly solution, but one way to get rid of your old motor oil.....LOL
 

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