• We’re currently investigating an issue related to the forum theme and styling that is impacting page layout and visual formatting. The problem has been identified, and we are actively working on a resolution. There is no impact to user data or functionality, this is strictly a front-end display issue. We’ll post an update once the fix has been deployed. Thanks for your patience while we get this sorted.

Repair rust damage?

T

TheKub

Golden Member
My girlfriend drives a 2002 Malibu and there is a rust patch just below the gas door on the rear fender. Its about the size of a baseball but I can see that it is starting to bubble the paint beyond what is rusted now.

What is the best way to fix this? We don?t care what it looks like in the end really we just want to stop\delay the rust eating a hole through the body.

I assume it involves chipping away all the bubbled up paint and grinding\wire brush\sanding away the rust then covering it with paint\primer\whatever.

On a whim I swung over to the paint isle last time I was in the store and they had spray on ?rust converter? or something like that. Would that be a worth while thing to use or just a normal spray on primer\paint.

Again we are not all that concerned with how it looks after the fact as she will likely be driving the car until it dies anyway.

Just wondering your guys thoughts.
 
Originally posted by: TheKub
I assume it involves chipping away all the bubbled up paint and grinding\wire brush\sanding away the rust then covering it with paint\primer\whatever.
Click to expand...

^ this is the only right way to do it.
 
The rust converters use some kind of acid (sulfuric?) to chemically change the rust into a hard, black substance. I don't know the chemistry or specifics behind it, but essentially it shouldn't rust again. However, it'll be very ugly, and there's still a chance that the areas with bubbled paint will still allow moisture in, causing rust to spread even further. Rust is like cancer to cars.

The best way is to simply sand it down to bare metal. Start in the middle and sand outward until you get past the bubbled paint, and go a centimeter further from that to ensure you get everything. Grab some primer (a good rattle can works fine, look for the ones with the "wide spray" tip, Duplicolor makes cans like that, and they work great), some paint, and go to town. If you want it to look decent, you'll want to sand the primer and paint smooth after you spray them, and end with a clear coat. It won't look anywhere near as good as if a body shop did it, but it'll certainly look better than rust, or the result of using a rust converter.

Finally, make sure to wipe / wash any gasoline that drips out after you remove the nozzle when filling up. Gas is a solvent, and it'll eat through paint and cause rust like this.
 
Originally posted by: CurseTheSky
The best way is to simply sand it down to bare metal.
Click to expand...

By this do you mean actual sand paper? And if so is there a particular grit(s) I should use?

Originally posted by: CurseTheSky
Finally, make sure to wipe / wash any gasoline that drips out after you remove the nozzle when filling up. Gas is a solvent, and it'll eat through paint and cause rust like this.
Click to expand...

Which is likely the casue of the rusting to begin with.
 
The cause is that the paint wore through and bare metal was exposed to air.

Yes, you need to sand all of the rust out, spray it with primer and paint it. But chances are that you're job will only last a few years.
 
Originally posted by: CurseTheSky
Finally, make sure to wipe / wash any gasoline that drips out after you remove the nozzle when filling up. Gas is a solvent, and it'll eat through paint and cause rust like this.
Click to expand...

This.

This is the main reason I never let the gas station attendants touch my car. I always shoo them away and insist on pumping it myself. Those guys don't give a fuck, they'll spray gas all over your car when pulling the nozzle out and not think twice about it.

As far as fixing it, do as others have said. Wirebrush all the rust away, primer and paint. If you want to get fancy, get some Bondo and a smoothing tool (paint scraper or similar) and apply it to the repaired area before priming / painting so you don't see the rust pits left behind. These look hideous if you just paint over them. Sand the bondo down so that it matches the body lines, primer and paint. Even a noob can usually achieve a presentable (if not professional) repair doing it this way.
 
Exactly. I always keep a sponge / squeegee tool in my trunk, similar to the ones usually available at gas stations, so that I can wipe away any rogue drops of gas after filling up. People always look at me like I'm paranoid, but it pays off when I get to smile and nod at the owner of a less-than-ten-year-old-car with a rust patch below the gas door. I just dunk it in the nasty fluid they make available for cleaning your windshields (how is it by 10:00 in the morning, every container's liquid is already brown?), wipe the area, squeegee it off gently, and tie the sponge tool's head in a plastic shopping bag to keep it from getting my trunk wet. Every so often I rinse it out to keep from contaminating everyone's windshields with extremely diluted gas (hey, I wouldn't want someone else doing it to me!).

If I can find a spray or squirt container that won't leak, I'll start carrying a bit of water around too. That way it won't suck so much when there's no windshield fluid available at the station. Anything with a screw-on top (like a usual spray bottle) seems to magically come open in the trunk after a while. Apparently the two small toolkits (~100 pieces total, but they're life savers), roadside kit (jumper cables, crank-up flashlight, reflectors, etc.), and snow brush / ice scraper in the trunk are doing some screwing (well, unscrewing) while I'm not looking.

I don't drive anything fancy (currently a 2008 Fusion, previously a 2003 Malibu), but it's such an easy thing to do and it makes a world of difference over time.

Anyway, back to the OP:

You can sand it down with whatever you're comfortable with. A power tool of some kind with a wire attachment (drill, Dremel, or "dedicated" tool) will probably be the quickest, but it may jump on you and accidentally hit perfectly good paint if you aren't used to using them. If you have a junk car or even a piece of scrap metal or hard plastic to practice on (old steel wheels may work), try that first to test how steady your hand is. Otherwise, sand paper will be a LOT of manual labor, but it's hard to screw up.

Keep in mind you'll have to sand down a good amount of perfectly good-looking paint to really get the job done right (probably an inch of "good" paint outward from the area in all directions), since rust spots will often have pockets or "veins" running beneath nearby paint. It doesn't hurt to mask off a large area outside of the rust / nearby paint using masking or painters tape to keep from scuffing the clear coat if you go too fast with the sand paper and jump or miss. Chances are it will polish right out, by why make the extra work for yourself?

The key is not to rush anything. No, it won't look perfect, but if you do a half-assed job, you'll get half-assed results (rust returning in a year, etc.). Sand it down to metal, mask off nearby good paint with tape and newspaper, grab a "wide tip" spray can of primer (such as Duplicolor, the tip should be advertised on the back), spray a coat, sand it lightly if it looks uneven, spray again, etc. Black88GTA's suggestion of body filler will give the absolute best results, but it can be a pain to get right. If you notice any major pits in the metal after sanding it down, it may be necessary (do this before primer). If you've ever used drywall mud to patch a hole, Bondo is somewhat similar in concept. Apply it, run a scraper over it so it's smooth and matches the curve / lines of the body, and primer / paint.

Finally, when you've painted it and lightly sanded any drips / imperfections, you can clear coat it and machine or hand buff it to a shine. Read up on car restoration or detailing for advice, but keep in mind that even a cheap buffing compound or polish with hand buffing pad and some elbow grease will give decent results.

I realize that everything I've written may sound like a lot of work, but this is the way I'd do it. If you really don't care how the car comes out in the end (as long as it looks better than it currently does), do whatever you feel fit. It's a decent car, though, and it can definitely be turned into a fun project and a learning experience at the same time.
 
Coincidentally this week I have been working on my Commuter (96 Accord) fixing the rust spots on it. I have one on the rear right fender (gasoline cap on the left side though) and I had some small rust spots on driver door and on front driver fender. In addition to two nasty rust spots on the very front of the car's top.

What I did was as follows:

1- Sanded rust and old paint till bare metal and went further a bit in the surrounding area to get it all.

2- Some spots had me eat much into the metal to get ride of rust, so I was prepared and I mixed some bondo and hardener up according to need and applied bondo filler to metal surface.

I used the bondo on my fender and car top as the rust had eaten up quiet a bit of metal there. Made sure to sand the bondo down to achieve same surface height and smoothness as car's non-rusted surface.

If you use a power sander and buffer you will get near car shop results. If you do it by hand like me, you might not get the smoothness as you like, it depends how picky you are.

4- I Gave it multiple coats of Duplicolor Black Primer (Car Color is Black)

3- I Sanded the primer till it became smooth enough (be sure to sand with appropriate grit sand paper)

5- Applied multiple coats of Black glossy Duplicolor spray (matches my car's color)

6- Clear Coat (I haven't done this yet though...maybe I should take care of that tomorrow 😉 )

Here are some pics of that car being naughty before I gave it some rust fixing punishment!:

Fender
Car Top
Car Top 2

The Car Top rust spots were the nastiest of all, because they were deep, had a couple of small holes too, I am glad I decided to work on it before they became an issue (i.e water leaks)

I didn't go about it the right way however (no welding), but I did it in a half assed way that works, I followed the steps I outlined on top, but before applying the bondo, I filled the two small roof holes with a Silicon gun, I applied generous amounts of silicon, waited hours for the silicon to harden up then I applied bondo, then sanded the bondo , then primed it then painted.

I will post pics tomorrow of the done job, it's not perfect, but I have almost no power tools (no buffer no sander none of that ) I just wanted to stop the rust, I am not too picky if it looks perfect...as long as the rust is gone I am glad.

Additionally, I applied silicon to the surrounding area of the rust, meaning all the rubber strips edges got silicon sealer into them to make sure water leaks don't become an issue in the future. Well the foreseen future anyways, if this works for less than a year I am happy...but I am sure it will work for years without issues, but I doubt I am keeping this car that long...I have an etch for something fancy shmancy 😛
 
Ok, thanks for all the tips. Unfortunately I got a chance to take a closer look at it today and looks like it far worse than I thought. Just picking at the loose\semi-loose material with my finger I picked out probably a 1\4? deep pit into the body. Id imagine if I was using some kind of sander\dremel tool Id likely punch through the body before finding clean metal.

Im assuming at this point a chunk of the body will have to be cut out and replaced\bondoed. Which if that is the case Im starting to feel that its out of the realm of what I feel comfortable doing DIY. Anyone have any more guidance or an idea of the cost of having a shop fix this. Again, we don?t want need it to look as good as new, as long as the rust is stopped or at the very least delayed we?ll be happy.


pic1
pic2
 
Originally posted by: TheKub
Ok, thanks for all the tips. Unfortunately I got a chance to take a closer look at it today and looks like it far worse than I thought. Just picking at the loose\semi-loose material with my finger I picked out probably a 1\4? deep pit into the body. Id imagine if I was using some kind of sander\dremel tool Id likely punch through the body before finding clean metal.

Im assuming at this point a chunk of the body will have to be cut out and replaced\bondoed. Which if that is the case Im starting to feel that its out of the realm of what I feel comfortable doing DIY. Anyone have any more guidance or an idea of the cost of having a shop fix this. Again, we don?t want need it to look as good as new, as long as the rust is stopped or at the very least delayed we?ll be happy.


pic1
pic2
Click to expand...

Holy shit. :Q

Just scrap the car.
 
Take it a few places and get some estimates. It's not a big deal to do so.

It will be cheaper to fix now than waiting any longer. There is that one area that's rotten, the rest is more or less surface rust at this point.

IMO that's from banging the fuel nozzle against the body. It probably started with a paint chip then gas running down it made it worse. Unless she's willing to be more careful, a repair would be futile.
 
This is a very common issue on GM's. The rust isn't from gas on the outside of the paint, it is rusting from the inside out from when rain enters in behind the gas door and drains onto the inside sheet metal. The only true way of fixing that would be to cut that area out and weld in a new piece of sheet metal. By the time the paint starts bubbling on the outside it is too late. Your sheet metal underneath is pretty much gone by that time.
 
You should see my van's 1/4 panels if you think that is bad. I'm "fixing" mine today. Just knocked the worst of the rust off and am waiting for the rust converter I put on it to do it job. Then I'll figure something out maybe chicken wire to use to give me a basic shape and bondo the hell out of it. Just has to look halfway decent to pass inspection and thats all I really care about. Its not a structural part and the rest of the van looks like ass anyway.

I'll see if I can get a pic of it later.
 
Originally posted by: boomerang
Take it a few places and get some estimates. It's not a big deal to do so.

It will be cheaper to fix now than waiting any longer. There is that one area that's rotten, the rest is more or less surface rust at this point.

IMO that's from banging the fuel nozzle against the body. It probably started with a paint chip then gas running down it made it worse. Unless she's willing to be more careful, a repair would be futile.
Click to expand...

it'd probably be a better Idea to just get rid of it, seeing as its a 2002 MALIBU. ick.
 
Originally posted by: thedarkwolf
Finished mine
before
after
before
After
lol
Went 1/4 assed on those. I ran out of bondo and decided I didn't really give a crap and just painted it after one coat. It will pass inspection now and thats all that really matters.
Click to expand...

What did you use inside the hole as a scaffold\base for the bondo? As ?ugly? as that looks that would be fine in my book because the car is mechanically sound and really only has to last a year or two.
 
Originally posted by: TheKub
Originally posted by: thedarkwolf
Finished mine
before
after
before
After
lol
Went 1/4 assed on those. I ran out of bondo and decided I didn't really give a crap and just painted it after one coat. It will pass inspection now and thats all that really matters.
Click to expand...

What did you use inside the hole as a scaffold\base for the bondo? As ?ugly? as that looks that would be fine in my book because the car is mechanically sound and really only has to last a year or two.
Click to expand...

Chicken wire and card board. I could have made it look just as good as from the factory with more sanding and more coats of bondo but didn't see much point. The rest of the van looks like this lol and that is the good side. It a beater and just needs to pass the state inspection.

Actually it wasn't chicken wire but pretty much the same crap. The dude at the hardware store called it hardware mat or something like that.
 
Originally posted by: thedarkwolf
Originally posted by: TheKub
Originally posted by: thedarkwolf
Finished mine
before
after
before
After
lol
Went 1/4 assed on those. I ran out of bondo and decided I didn't really give a crap and just painted it after one coat. It will pass inspection now and thats all that really matters.
Click to expand...

What did you use inside the hole as a scaffold\base for the bondo? As ?ugly? as that looks that would be fine in my book because the car is mechanically sound and really only has to last a year or two.
Click to expand...

Chicken wire and card board. I could have made it look just as good as from the factory with more sanding and more coats of bondo but didn't see much point. The rest of the van looks like this lol and that is the good side. It a beater and just needs to pass the state inspection.

Actually it wasn't chicken wire but pretty much the same crap. The dude at the hardware store called it hardware mat or something like that.
Click to expand...

Give us an update on how it holds up after 6 months.
 
Originally posted by: LeetViet
What did you use to attach the chicken wire to the panel?
Click to expand...

Can't really tell in the pics but there is an outer and inner piece of metal in those spots and I just jammed the chicken wire in between them. If I couldn't do that I would have just used tape or just held it with my hand long enough to get the bondo in place and then it would hold itself. Had to hold it with my hand anyway to keep shape.

As for how it will look in 6 months? I don't give a shit. Just has to look good enough to pass inspection in a couple days. I imagine it will look much the same in 6 months though. 2 or 3 years from now is a different story. The whole car may have been crushed by then if not I'll throw more bondo at it.
 
Originally posted by: canadageek
Originally posted by: boomerang
Take it a few places and get some estimates. It's not a big deal to do so.

It will be cheaper to fix now than waiting any longer. There is that one area that's rotten, the rest is more or less surface rust at this point.

IMO that's from banging the fuel nozzle against the body. It probably started with a paint chip then gas running down it made it worse. Unless she's willing to be more careful, a repair would be futile.
Click to expand...

it'd probably be a better Idea to just get rid of it, seeing as its a 2002 MALIBU. ick.
Click to expand...
On behalf of the OP, I'd like to thank you for your helpful post. Post count +1, eh?
 
You must log in or register to reply here.

TRENDING THREADS

Back
Top