Can I Fix Rust Spots Without Repainting Entire Car?? - PeachParts Mercedes-Benz Forum

#1 06-30-2006, 12:18 PM

I have an 85 300TD wagon that I recently bought. On first look she looks mint, but I notice the beginings of what looks like some rust about the wheel wells and around the rear windshield seal and around the antenna. I found a body shop advertising on craigslist that just opened and claims to do good work at half the price of a regular shop. I bring the wagon up there for an estimate. The guy pulls off a couple of the lower moldings and to my surprise there is rust down there with a few small holes. ALSO AT THE BOTTOM OF THE PASSENGER DOORS THERE IS WHAT LOOKS LIKE SURFACE RUST, ITS NOT ROTTED THROUGH but it looks like only on the surface. So I tell these guys I want to keep this car forever and it fixed properly, not just bondo over the rust like maaco. The guy says I should paint the entire car because he cant match the paint. They give me a price of $2500.00 to paint the entire car, pull off all the trim and moldings and repair ALL the rust with sheet metal and no bondo. So I am contemplating what to do. I love the car, but I really did not think it needed an entire paint job. Granted after 20 years it could use it. SO I am in between a rock and a hard place. also my concern is the quality of the paint, it may now be as nice as the factory original. should I just fine a place that can fix and patch only the rust? Another concern is, It may be $1500.00 just to fix the rust, and if I go that far am I better off letting them paint her too? Please help someone!!!

rrgrassi · #2 06-30-2006, 12:35 PM

It all depends on how much you love the car, and what is the price of that love. The replacing sheet metal is the best way to go to get rid of rust, and that entails a lot of cutting out the old, rusty metal. A good shop will cut where there is no rust found. $2500 for all that work is not bad, if you plan on keeping the car for the long haul. A full repaint hides the repair, kinda like repainting an entire wall in your house after doing some sheet rock repair.

tobybul · #3 06-30-2006, 12:41 PM

I am also working on some minor rust spots on my 85 300D that I recently got. depending on on how fancy you wanna get, there are plenty of paints and materials out there to use.

One of the first things I did was go to an automotive paint supply place and had them mix the paint of my car. I went to Sherwin Williams's automotive paint store. the color code can be found stamped under the hood. mine is 702 for the color of my car. I got a pint of it for $16. got small brushes and just hand brushed them (after doing the necessary preps). I happen to have a detail sander which was handy for getting as much rust out as possible.

theres rust converter solutions also that you can apply b4 u paint, primers, sand paper, etc.

#4 06-30-2006, 12:51 PM

Quote:

Originally Posted by rrgrassi

It all depends on how much you love the car, and what is the price of that love. The replacing sheet metal is the best way to go to get rid of rust, and that entails a lot of cutting out the old, rusty metal. A good shop will cut where there is no rust found. $2500 for all that work is not bad, if you plan on keeping the car for the long haul. A full repaint hides the repair, kinda like repainting an entire wall in your house after doing some sheet rock repair.

YEs I agree, $2500.00 is not bad, but I am just wondering if they will really do as good a job as they say. There are 2 yound guys that just opened, they dont even have a phone in yet so I can see that they are hungry for the business. Perhaps thats a good thiong or maybe its a bad thing, I dont know. I am wondering what it will cost just to fix the rust and patch it with the entire paint job. Although it probably makes sense to do the paint since they have to strip the car anyway

KCM · #5 06-30-2006, 12:59 PM

What you have found out is the hidden secret of rust: even though it only shows up in small spots or bubbles visually, it is usually heavily entrenched under body mouldings or undercoating. Once you start poking at it, it will quickly enlarge to holes through the panel. Thats why people need to be very cautious when any rust is seen on a car they are considering purchasing.

I know for a fact that you do not need to repaint the whole car to fix certain areas, though it is a good idea to repaint a whole panel (or at least up to a body line). But even patch painted areas can be buffed to blend in with the surrounding area.

I had a local bodyman take a dent out of my car and repaint some rusted areas I fixed myself. My color is a hard to match gold metallic, and he matched it 100% perfect to where you cannot tell it had ever been repainted. And I know he did not paint the whole panel in certain areas.

If you plan on keeping the car and it is good shape mechanically and interior-wise, cutting out the rust and replacing the metal is the way to go. Body filler is the cheaper and quicker way, and if done right, will hold up well. But even with that, any holes should be welded shut to prevent moisture from coming from behind and being absorbed by the filler. In addition, rust inhibitors should be used to prevent the rest from seeping around the filler and showing up years down the road. Rust is like cancer, you are better off catching it early.

rrgrassi · #6 06-30-2006, 01:21 PM

If the shop just opened, you may be in luck as far as quality of work. If they are fresh from Auto Body school, then they might not have been taught the "how to cut corners, but look like you did not" trick. Plus, new shops that are hungry for work usually do really good work, since good work brings business and shoddy work will cause them to shut down as word gets out. If it was my car, I would have it fixed right.

The problem with bondo, fiberglass repairs, etc, is that rust can come back to the repaired place, due to air bubbles and other imperfections. Undercoating not applied properly can be a nice rust haven, since it can hold water.

Endust · #7 06-30-2006, 03:42 PM

When they say no bondo they dont mean it. For the price they quoted you they will have to at least skim coat the patches so hide the imperfections. Not that there is anythong wrong with that if done correctly. Correctly done filling can last for a VERY long time. However, very few shops will do it correctly due to the time it takes. A good chunk of the $2500 will be in the paint job. That doesnt leave many man hours or materials for the repairs.

If you want perfect, replace the rusty doors with donor rot free doors. Just pick and pull the shells and swap your stuff into them. Then its just paint work. Otherwise expect them to cut out the rotted sections, weld in new ones and skim coat bondo over the area to smooth it out. Done well can last a real long time. Done wrong on a door you will see rot bubbles in 2 years.

One this to ask them would be the welding method they plan to use. The best long term method is a butt weld. A skilled person with many hours can butt weld a patch in and finish it without bondo. Takes a LONG time that way but its like the rot never happened. However, the faster more common method is to overlap the patch by using a flanger on the patch piece. Then you can drill holes in the original sheet, fit your patch with the flanged section under the good section, and plug weld the holes. Much less time involved im making the patch area and easer to grind down and finish. Also leaves a nasty overlap thats rarely sealed from the back side and rots like crazy in no time.

Bottom line is you get what you pay for so ask lots of questions!!

t walgamuth · #8 06-30-2006, 04:52 PM

if the paint is not a metallic you can patch in touch up paint mixed to match from the original colors pretty successfully.

i am always reluctant to do a full paint job cause it will never be as good as the original one and usually there will be areas that werent fixed quite right or sanded quite right that peel or bubble soon after the new paint.

the exception is a rust free car that just needs a shiny surface.

tom w

300SDog · #9 06-30-2006, 07:42 PM

Yeah and what color is the existing paint? Some colors are obviously easier to match then others. For example, if it's silver or black I'd opt for a partial paint job without hesitation. But not necessarily if it's red or green or blue.

Hatterasguy · #10 06-30-2006, 08:00 PM

I can't see how they can do that kind of work for $2,500. I'd expect the price to be double or triple at least.

Is the rust on the doors? If so it would be cheaper, simpler and better to get good used rust free doors. Then just paint them and bolt them on. Buying a used rust free door is cheaper then paying someone $70 an hour to cut out and weld new sheet metal on your old doors.

Good body work is extremly time consuming, cheap body work is not.

#11 06-30-2006, 08:45 PM

The color of it is Grey according to the title, but it really looks llike a cream or color or a grey with a hint of light brown. Not a silvery grey. The doors are really not that bad, there is no rust on the outside, just the beginings of surface rust on the lower inside door near the rubber. But if I am better off buying new doors, than maybe I should just say the heck with the doors and just sand it down a bit and put some eastwoods on it and just get the lower fenders done. The question is where should I take it and how do I know they are doing it right?

tobybul · #12 06-30-2006, 10:47 PM

One of the areas that rust hides in this car behind the rubber moldings attached to the bumper on each of the 4 corners. Theres metal bracket each held by 2 bolts and a screw to the body that holds the moldings. In mine, these were practically disintegrated by rust. I took them all out and are doing without them for now. Also, the rubber on top of the bumper is held to the body by a metal strip with about 8 screws. These were also just about gone. In some spots where the screws are, there were rust contaminated by the metal strip.

I can't imagine what the autobody shop would do about this.

These are mainly the areas I repaired.

I too got a quote from a shop initially for $2600 but the proposal sounded a bit unclear. To do it right, you need to bring it to an outfit that restores vehicles probably buckooo bucks.

Hatterasguy · #13 06-30-2006, 11:02 PM

The "right" way to fix bad rust is to cut out the affected area and replace it with fresh metal. Surface rust can be sand blasted and then the metal can be repainted. Of course their are other options, some are very good.

Their is a very good body shop in my area that does do restorations. They have done some amazing work but good body work does not come cheap. They wanted $3k to properly remove and fix the rusted shelf below the rear window on the SDL. They would only put their name on it if it was a proper job, they would not entertain the idea of anything short of cutting out the bad metal and making a new part. I could not afford it at the time so I did it myself and encased the rust to buy a few years. In a couple of years it will be delt with.

Depending on how bad the rust is, and this is close to impossible to determine online, having a top notch body guy cherry out one of these cars will cost a fortune. I'd expect about $5k for one with a pretty straight body to upwards of $10k quickly if it has issues.

#14 07-01-2006, 01:16 AM

Quote:

Originally Posted by Hatterasguy

I'd expect about $5k for one with a pretty straight body to upwards of $10k quickly if it has issues.

At least, I have an estimate for about $2K just to clean up a few stone chips and dings, stuff you can't even see from 10 feet away.

bgkast · #15 07-01-2006, 02:11 AM

I will be doing some similar repairs on my car in the next few weeks. I have to cut out a 1/4 sq. foot of panel in the trunk and weld in a patch, then repaint the patch. I plan to take some photos and do a write up so keep an eye out. If I am able to get the bodywork to look decent than anybody should be able to.