What to do about a rusty frame?

[strantor]

My daughter and I are fixing up an old truck (91 Chevy S10) and the frame is rusty. We've got the bed off right now but no plans to remove the cab. I can't wrap my head around the rust on the frame. It's all surface rust, nothing bad at all, but it's the ENTIRE frame. Every square inch of it. It's like the frame is only a year old but never got painted. Or like every square inch of paint simultaneously fell off of it a year ago. How does that happen?

Anyway I don't know what to do about the rust. Anything I do is going to feel half-ash since I won't be able to get the front half. But I don't want to do nothing. Someone recommended coating it in ospho, but my understanding is that ospho needs to be followed up with paint or else it's worse than pointless; the rust will pick right back up where it left off and be worse than before. Is that correct? Or can I just spray ospho all over and proceed with confidence that I've done something better than nothing?

Can I just spray old motor oil on it to stop it progressing?

What would you do? This truck will probably only stay in the family for a couple of years until my daughter goes off to college in a newer vehicle and I either sell this or do a frame-off restoration on it.

 

[jaxs]

If you look at frames of cars and trucks more than a few years old,they are exactly as you describe. Forgetaboutit and move foward with mechanicals and noone will ever know the differene.

 

[ponytug]

If it were me, I would vote to cut your losses. If it isn't going to be with you long term, avert your eyes and move on.

If you really are considering a frame off restoration, I wouldn't do anything that is too hard to undo. (E.g. diesel/motor oil is ok, painting isn't, unless you have a local stripping tank.) Given where you live, it probably won't get too much worse in a few years.

My bet on the all over rust would be some beach off roading to sand things off and a quick dunk through some waves to get salt everywhere and the rust started. Or just a gentle dunk in storm surge. Whatever it was, it happened.

Have fun!

Peter

 

[RustyA]

Up North in the salt belt rusty frame means something different. 2004 models you can see through the frame, shackle supports rusted off with spring penetrating bed, fuel tanks held up with ratchet straps because nothing left of frame member supporting tank straps. That's frame rust!

 

[LouNY]

Given your intended usage I'd just coat the frame and the under body with fluid film or a similar product.

 

[Jstpssng]

I haven't tried it yet but this stuff https://www.amazon.com/Magnet-Paint...hvlocphy=&hvtargid=pla-4584207577478177&psc=1 is supposed to work good.

 

[dodge man]

If it really is just surface rust and it isn’t damaged, I’d use something like fluid film. They make kits for spraying it on.

 

[ROUSTABOUT]

I've got trucks all the way back to 1941. Frame never messed with and it's still fine. But, I have one that is bad. In the glove box I found papers from Michigan, so I understand.

 

[ChuckT]

Only one solution - IF & only IF, because of the effort and price involved, is to remove the frame from the body and the engine & running gear, strip and repair as needed, then high zinc primer then paint with "undercoating" (covers and still allow the frame to flex) then put everything back. Of course you could also do the smart thing and replace the frame with an after-market "box" frame and ... etc. But it doesn't sound like you want to

 

[bdhsfz6]

As others have said, unless you're doing a complete restoral on the vehicle, I wouldn't worry about it since you aren't going to keep it long term.

That being said, I would check the frame where the front suspension is attached. I had a 1994 S-10 where the frame rusted to the point where I had to weld on reinforcing plate. The truck had 120K hard miles on it and was stored outdoors before I bought it though.