Hi,

I was wondering if some of you DIYer body type would lend some discussion on rust concerning these body styles.

I have been looking for another 300D/CD and it seems anything I consider has some amount of rust expecially if it a northern car. My question is simple.. how much rust is too much? I have been told that MB rusting in certain spots should be avoided and used as 'parts' only type cars.

What places are harder to fix then others? How hard is it to fix and replace rocker panels?

Hoping to see a good discussion get started.

Thanks,

Morph

Where you dont want rust is on the frame or the floor pans. Just crawl under and look, its pretty easy to see. I recently sold my 82 300SD that looked like swiss cheese, but had no structural rust, so I bought it, had fun with it for a while, cleaned up some of the rust then sold it.

This car sat from 5/98 to 7/01, not being started once. It had 253K, put a new battery, glow plug, and a glow plug fuse in, and it fired right up in 3 cranks.

Morphous,

I don't know where you live but consider going south to get another 300. Mine lived in Atlanta for its first 15 years and there is zero rust anywhere. Worth a road trip to find one without rust problems. And they are relatively cheap north or south. Do watch for "southern" cars that are near a beach....thats probably just as bad as road salt.

Nic in SC

Okay, so what does one do when they think they see two rust blisters on the lower rear quarter panel of their 85 300D? Is there a zinc product to put on to avoid the bubbles from getting bigger???

A good approach is to get a CarFax report to review the title history of the car. A lot of "old buzzards" retire to Florida and take their "rustbelt" northern car with them.

It seems like a tradeoff to some extent. Northern car = rust. Southern car = sun damage. True, the rust is more serious.

Maybe North Carolina cars are the best?

I have a small rust issue behind the right rear wheel on my '82 300D. It looks like it probably started from a rock ding that wasn't treated, rather than salt eating away from the inside. I can see where there are other rock dings on the other side that need to be treated.

So, to build on the thread, what is good to treat the rust before covering it over with that most glorious of products, Bond-O :) ???

For minor surface rust (i.e. not the cancerous bubble type) Trak Auto sells a spray-can rust treatment that converts the rust to "sandable primer" after a few coats. It works well - I used it in the trunk area where there was some rust from the rubber plug decaying. Replacement plug less than $1 - why do people ignore this type of thing?

Ken
'82 300D

The crazy thing about my two small bubbles are that they are on a part of the rear quarter that is coated with undercoating then painted the color of the car. They are tiny, I think they are rust-like? I think they can be treated, but don't want to ruin the paint...

Good points all,


However, I want to stress the fact that if you must consider a car with rust... how much is too much? What places are the hardest to fix and should be avoided?

I am hoping that others that have restored these cars with new paint and fixed rust spot can contribute to this discussion.

If I can purchase a car rust-free, that's always my first choice. But if I must settle, then what is the dividing line of buy vs avoid?

Morph :confused:

Randall,

The "bubble" you describe, unfortunately, is probably a spot where rust has completely eaten away the metal underneath leaving only a thin skin of intact paint. My '83 240D had two such spots, one on each front fender immediately behind the wheel well, beginning underneath the lower rocker molding trim and growing upward. I recently had the rust repaired and the whole body repainted, and when the body shop guy took a look at those spots he just tapped them with his fingers (!) and the paint crumbled away to leave a gaping hole.

Photos of before and after, just click on the links that say "Rust spot" and "no rust spot":

http://home1.gte.net/res0holb/index.htm

Good luck with it.

- Nathan
'83 240D "Steiner"
'00 New Beetle TDI

My brother and I are about half way through a resotration of a 1975 300D.

All the body parts can be replaced by welding in new sheetmetal, but cost is prohibitive if you have someone else do it. Most 123 sheetmetal stampings are probably still available if you dig long enough and will pay what is required ($$$$$$$$).

There are a couple of places that have OEM and replacment stampings, and one can always hammer out replacments from flat sheetmetal if willing to spend the time. Again, don't plan on having a body shop do this unless you are rich and want to keep someone employed for long periods of time!

If you have a welder and can learn to weld sheetmetal, or have a buddy you can bribe into the job, these cars aren't too bad. The body is made up of a series of stamping spotwelded together, so it can be completely disassembled by drilling out the spotwelds and re-welding new stuff in. Rocker panels are a typical repair and are easily available, as are floor pans, usually complete with seat brackets.

One thing to watch for is a leaking rear window, ina addition to plugged water drains in the rear fenders and under the dash -- water on the floors will rapidly rot them out, specially if there is any salt in it. Both of out 115 chassis have rotten floors from leaking windows, front and rear.

If you can take six months or so, and do the work yourself, resoration isn't too bad. Better to find a car with the engine and transmission trashed with a good body, though.

Avoid anything that has been wrecked, though -- takes a special frame puller and expert operator to get them straight. The last word I've gotten is that if the floorpan or roof are distorted, pass. Bent front and rear crush zones can be replaced or straightened fairly cheaply.

Peter

Actually, my two bubbles are firm to the touch, I'm thinking and hoping surface only.... What can you do??? I keep them clean and what not. They are really small and hard. I'll have to watch them... Thanks for the advice though...

Randall:

Check the body panel with the rust blisters from the back. Rust "blisters" usually are a result of a scratch and rust under the paint, (like the tops of the doors on my 220D) or a hole from the back covered only by rust flakes and remains of paint. The surface ones arent' too bad. Rust from behind is a problem!

If it is only surface damage, get some sandpaper, some touch-up paint, and some conversion or etching primer.

Sand off the blister to clean metal, then prime. The primer will convert the rust to an inert iron compound, usually stopping the rust. Paint the spot with touchup paint (MB's is good original type laquer or enamel). If the area is large, get it professionally done, an amateur job can usually be spotted from a mile or two.....!

Rust from the back (actually a rust-through) is much worse, and I'd not recommend you fix it yourself unless you know how to do bodywork.

Peter