Body Repairs

**MD4x4 Fireman** · 07-15-2007, 06:31 PM

I am not sure if this is in the right place. But I am about to start to work on fixing some rust spots on mytruck. Can someone give me some pointers, I have never done it before. Ideas on what to buy as far as tools and bondo brands and things to watch out for. Any help would be great.

**Paul M** · 07-15-2007, 09:22 PM

In my case, body repairs are usually left to the experts. I will clean up surface rust on the underside of the vehicle with a wire wheel on an electric drill, clean with a chem cleaner, rinse, let dry, and then prime and paint. Also, undercoat if desired. I am in Az so I do not always undercoat.
I never bondo. I guess you can do the repair this way if you are just looking for a quick aesthetic repair, but it is not a good repair.
The rusted metal needs to be cut out and a metal patch installed; or better yet - the panel is replaced. Vehicles have sheetmetal panels heli-arced in place. These panels can be replaced. They have the proper shape and form.
Paul M.

**tbplus10** · 07-15-2007, 09:37 PM

If your repairing rust spots it'd be much better to do patch panels and panel replacements instead of bondo. Bondo gets moisture behind it most times and creates more rust later.
LMC truck sells patch panels or replacement panels for all rust prone areas on almost every GM truck ever built.

If you decide you must use bondo the Bondo brand is pretty good.

For bondo repairs remove all the corrosion and paint in the affected area with a grinder or very abrasive circular style sander.
If you have rust through you'll need to repair it with fiberglass patches behind the panel, then use bondo over top to recreate the body lines.
Mix up only enough bondo to do 1 spot at a time.
Apply bondo no more than a quarter inch thick.
Allow an appropriate time to harden.
Use a grater to bring the bondo close to the body lines then sand it down the rest of the way to match.
You may have to use more than one layer of bondo to get things perfect.
After you have the panel smoothed and the lines matched up use spot putty to fill in any small holes and imperfections.
Wet sand the panel with very fine sandpaper.
Dry the panel, and then use a tack cloth to remove any debris, or oils.
Primer the panel right after completing the work to protect the metal.
I'd find an old fender or door to practice on before attacking the vehicle.
If your working on any dents or gouges that are over a quarter inch deep you need to pound them out with a dolly and hammer prior to applying bondo.
Air tools make the work go much faster.
Items required:
Longboard
Sanding block
Grater
Masking tape
Primer
Bondo
Bondo spreader
Bondo mixing plate
Different grades of sand paper
water bucket
Tack rags

**MD4x4 Fireman** · 07-15-2007, 10:07 PM

i am fixing some rust holes in the cab corners. well i think i will try it on wednesday. i will let ya know how it goes. thanks for the help so far

**dwill3015** · 07-15-2007, 10:25 PM

For patching any rust holes, you will want to use Duraglas fiberglass filler as it mixes and spreads just like plastic filler (Bondo) but is waterproof and rust-proof. USC also makes the best plastic filler IMHO.

**Cableguy** · 07-15-2007, 11:06 PM

Ah the cab corners of a Chev truck what a classic repair. They do make after market corners to be welded in this is the only way to do them IMO. Then spray under coating in that cavity from behind.

**tbplus10** · 07-15-2007, 11:07 PM

Duraglas is good stuff but if your a novice trying to learn while doing the job it can be hard to use, it hardens fast.

**dwill3015** · 07-16-2007, 12:11 AM

Originally Posted by tbplus10

Duraglas is good stuff but if your a novice trying to learn while doing the job it can be hard to use, it hardens fast.

It would be much easier to use for minor rust instead of panel replacement depending on the severity of the rust, and of the ability of the repair person.

**MD4x4 Fireman** · 07-16-2007, 10:37 AM

i dont know how to weld or have anyone near me who can. i was thinking of using some kinda patch then fill it the little area to made it even with the body. i just need a fix to get it to pass inspection then i will find someone to weld it later.

**84fiero123** · 07-16-2007, 05:50 PM

Originally Posted by Cableguy

Ah the cab corners of a Chev truck what a classic repair. They do make after market corners to be welded in this is the only way to do them IMO. Then spray under coating in that cavity from behind.

Agree completely, but then I do know how to weld, all to well.

But for the welding impaired there is always, rivets then take it to a local welder to weld it permanent. Then you grind out the rivets. Do the mud work as described above. And your done.

Welded on the line at GM for 3 years.

Shame you ain’t closer.