Frame rust repair
- Thread starter chevchev
- Start date
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DerekTheGreat
Forum Regular
Hmm. Do what the previous owner did and spray more bedliner "rust proofing paint" on it and ship it.
stutaeng
I'm Awesome
No experience on doing this type of vehicle frame corrosion repair.
But I've designed and specified plenty of steel structural repairs to buildings. The first step is to clean all of the scale off with mechanical or blast media. In my experience, once that's done everything looks worse.
Then if the steel section is still salvageable, it's just a matter of cutting out and doing a complete joint penetration welds or slapping supplemental steel (at least as thick as the base metal) and doing a fillet weld all around. Shoring structural members is necessary; in your case, that means supporting the frame so you don't unintentionally weld a sagged frame after you've cut metal out.
It also depends where the rust is and what kind of forces are there on area being repaired. I have no idea what that is on a truck frame, and it depends what part of the frame this is on, but if I had to this, I'd be generous on any thickness for any metal being retrofitted.
If the frame is Swiss cheese, may be better to do a frame swap, or replacing that single member with a good one.
Good luck.
Edit: it's pretty obvious, but if not, I was assuming you had welding experience, preferably welding in all positions, i.e., flat, vertical, and overhead and a good welder.
But I've designed and specified plenty of steel structural repairs to buildings. The first step is to clean all of the scale off with mechanical or blast media. In my experience, once that's done everything looks worse.
Then if the steel section is still salvageable, it's just a matter of cutting out and doing a complete joint penetration welds or slapping supplemental steel (at least as thick as the base metal) and doing a fillet weld all around. Shoring structural members is necessary; in your case, that means supporting the frame so you don't unintentionally weld a sagged frame after you've cut metal out.
It also depends where the rust is and what kind of forces are there on area being repaired. I have no idea what that is on a truck frame, and it depends what part of the frame this is on, but if I had to this, I'd be generous on any thickness for any metal being retrofitted.
If the frame is Swiss cheese, may be better to do a frame swap, or replacing that single member with a good one.
Good luck.
Edit: it's pretty obvious, but if not, I was assuming you had welding experience, preferably welding in all positions, i.e., flat, vertical, and overhead and a good welder.
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DeCaff2007
I'm Awesome
That looks pretty similar to what I had to deal with. I ended up cutting out all of the rotted sections and replacing with 3/8" steel plate. Took damn forever but it's done.
Canadian Rust Bucket
I'm Awesome
That looks pretty rough. Mine wasn't quite that bad, but I basically did what @stutaeng outlined above.
But to strip it down to clean metal, so you can see what you're actually working with, is a pretty involved endeavour. I started by getting a needle scaler and air chisel and mechanically removing the rust. Once you've chipped off the loose stuff, wire wheel and flap disk it. Then follow with a muriatic acid bath to remove trace rust. Repeat as necessary until all you have is bare steel, then you'll see if there's even enough to save.
It is vitally important not to paint over a rust chip; it's like leaving a piece of cancerous tumour behind. It comes back with a vengeance.
If you do decide to go ahead and cut/weld the rusty steel, make sure you cut well past the hole in both directions. Several inches, wherever possible. When I was doing my frame I went almost six inches past the last obvious weak spot.
You might not be able to see it from your perspective, but I can almost guarantee there's more weak metal surrounding the breaks.
It's also important to get some kind of coating on the steel quickly to stop it from flash rusting. I used Tremclad paint and primer and am pleased with the results. Other than the spots where I didn't do a good enough job in the prep stage the first time, the adhesion and rust prevention have been top notch.
Your rust is at the rear cab mount next to the gas tank and on the spare tire crossmember, right? I'd just swap the crossmember if you can find a replacement, and pull the bed / drop the tank to give you good access to the trouble spots.
But to strip it down to clean metal, so you can see what you're actually working with, is a pretty involved endeavour. I started by getting a needle scaler and air chisel and mechanically removing the rust. Once you've chipped off the loose stuff, wire wheel and flap disk it. Then follow with a muriatic acid bath to remove trace rust. Repeat as necessary until all you have is bare steel, then you'll see if there's even enough to save.
It is vitally important not to paint over a rust chip; it's like leaving a piece of cancerous tumour behind. It comes back with a vengeance.
If you do decide to go ahead and cut/weld the rusty steel, make sure you cut well past the hole in both directions. Several inches, wherever possible. When I was doing my frame I went almost six inches past the last obvious weak spot.
You might not be able to see it from your perspective, but I can almost guarantee there's more weak metal surrounding the breaks.
It's also important to get some kind of coating on the steel quickly to stop it from flash rusting. I used Tremclad paint and primer and am pleased with the results. Other than the spots where I didn't do a good enough job in the prep stage the first time, the adhesion and rust prevention have been top notch.
Your rust is at the rear cab mount next to the gas tank and on the spare tire crossmember, right? I'd just swap the crossmember if you can find a replacement, and pull the bed / drop the tank to give you good access to the trouble spots.
Thanks a lot for your replies, it isn’t as bad as it looks in the pictures. Before i took the pictures i hammered all around the cracks/holes to get all the lose rust off, so its mostly "hard" steel left, its thin around the cracks, but it is steel. This is probably the result of an inch of sand inside the frame. Bought it about two weeks ago and found the rust damage a few days ago. The rest of the frame looks good so far so i hope i can patch it safely. Yes the cracks is next to the fuel tank, thats how i found it, need to replace the fuel pump. The first picture is right behind the rear bumper.
Edit: This is a 2002 Tahoe.
Edit: This is a 2002 Tahoe.
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