GM Truck Club Forum banner
1 - 17 of 17 Posts

·
Registered
Joined
·
1,106 Posts
Discussion Starter · #1 ·
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. :confused: :confused: :confused:
 

·
Registered
Joined
·
83 Posts
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.
 

·
Premium Member
Joined
·
6,542 Posts
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
 

·
Registered
Joined
·
1,106 Posts
Discussion Starter · #4 ·
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
 

·
Registered
Joined
·
4,151 Posts
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.:great:
 

·
Registered
Joined
·
2,966 Posts
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.
 

·
Premium Member
Joined
·
6,542 Posts
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.
 

·
Registered
Joined
·
4,151 Posts
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.
 

·
Registered
Joined
·
1,106 Posts
Discussion Starter · #9 ·
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.
 

·
Premium Member
Joined
·
1,625 Posts
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.
 

·
Registered
Joined
·
1,106 Posts
Discussion Starter · #11 ·
yup.... im about to just say who cares and rivet it and leave em there and use bondo to even out the surface
 

·
Registered
Joined
·
233 Posts
Which welder would you use for this mig or tig? ive done some welding in a shop class, but i dont even remember what is was, i wanna purchase one and start practicing, as if i had had one many times before, it would have made my life much easier lol and woulda brought some cash in. so like for exhausts, and body repair, what would you reccomend.?
 

·
Premium Member
Joined
·
6,542 Posts
Which welder would you use for this mig or tig? ive done some welding in a shop class, but i dont even remember what is was, i wanna purchase one and start practicing, as if i had had one many times before, it would have made my life much easier lol and woulda brought some cash in. so like for exhausts, and body repair, what would you reccomend.?
Assuming your skill level is a beginner I'd recommend a wire feed MIG welder with an optional gas setup. 110v would work o.k. for the jobs you listed, but if you can afford it 220v would be a better machine that'll do more jobs as your skill level gets better.
I have both machines (110 and 220 both with gas), I find myself using the 110 with flux core wire for most jobs unless I'm bulding a structural component that needs deep welds.
TIG's are very nice versatile welders but the purchase cost prohibits them from being bought for use in a home garage.
Arc welders (cracker box) are real handy to have around in a pinch and you can usually find a decent used 220 for under a $100.
And last but not least an Oxy/acetalene (sp?) welder is useful to have. You can do brasing and lead filling, and heating to bend items.
 

·
Super Moderator
Joined
·
3,410 Posts
When I get the chance, I'm going to get me an oxy/acetylene torch for cutting and heating, and a 200v MIG with gas setup. I have some access to an arc, oxy/acetylene, and a MIG, but I have to drive 45 mins to get to them and can't really do big projects where they're at. I don't particulary care for arc, I've never had formal training (or really any for that matter, I just kinda figured it out on my own) and I tend to either burn the metal or get the welding rod stuck to the piece :eek: .
 

·
Premium Member
Joined
·
6,542 Posts
When I get the chance, I'm going to get me an oxy/acetylene torch for cutting and heating, and a 200v MIG with gas setup. I have some access to an arc, oxy/acetylene, and a MIG, but I have to drive 45 mins to get to them and can't really do big projects where they're at. I don't particulary care for arc, I've never had formal training (or really any for that matter, I just kinda figured it out on my own) and I tend to either burn the metal or get the welding rod stuck to the piece :eek: .
After 20+ years using arc welders I havent quite mastered it either, I blow holes in the metal and leave boogers at times. Arc is the cheapest to buy and when used correctly by a skilled welder can do awsume welds on anything from heavy gauge structural steel to light weight sheet metal.
I'm saving my pennies for a Plasma Cutter. I cut with my gas rig but after seeing a friend cut with the Plasma it's the only way to go.
 

·
Registered
Joined
·
83 Posts
Truck Repair

Hi Matt. Does a Maryland inspection actually fail you for rust in this type of location?
 

·
Registered
Joined
·
83 Posts
Ok Tim. You blow holes in the metal with an arc welder and you can cut real well with a plasma cutter BUT what can you use OR is available that will be more forgiving? How is heli arc? I thought this is the way they do body panels. I have no experience but am thinking of taking a step forward. I have some old cars so I do not know if heli arc was around then but we are talking about 80s to 2007 trucks.
 
1 - 17 of 17 Posts
Top