300D (W123) Weld repair of rusted chassis & floorpans - PeachParts Mercedes-Benz Forum

Graham · #1 10-02-2012, 10:01 PM

I have posted about the hidden rust that I have been uncovering on my 85 300D. To recap, I started off noticing some rust on the inner rear wheel arches. Then I checked under front carpets and found floorpan to door sills rusted. PLus some rust on floorpan. Then found more on passenger side firewall to cabin wall joint. And more at front end of rockers.

There is a guy who will do the weld repairs for me, but it will probably get into $3k range and I won't know if we have got it all (without stripping all undercoating).

I think it is best to just sell it as-is. But what is it worth?

1985 300D
- 420k km on chassis, <100k km on replacement engine rebuilt 2001.
- Transmission & rest of drive train seem good.
- Exterior sheetmetal, chrome and paint excellent (repainted 7 years ago)
- New front fenders installed when repainted.
- Interior very clean - just one defect on driver side seat.
- Car runs very well and no known mechanical problems.
- A/C disconnected

More pictures here (just after repaint, but still looks same)
Post your diesel!

Some, but not all, of the rust:

Oracle12345 · #2 10-02-2012, 10:04 PM

i would start at 2k or best offer honestly

Graham · #3 10-02-2012, 10:28 PM

Quote:

Originally Posted by Oracle12345

i would start at 2k or best offer honestly

I would be happy with that!

vstech · #4 10-02-2012, 10:31 PM

Hmm those are some BAD places to have rust... but they look fairly easy to repair, most shops in your area should be experts in this minor amount of cancer.
full disclosure, you're looking at maybe 1500...
I'd keep shopping for a welder that'll work on it for less. I'd think under 1K to fix that well, perhaps under 500 if you help, and you treat the metal after the welds are done...

Graham · #5 10-02-2012, 11:00 PM

Quote:

Originally Posted by vstech

Hmm those are some BAD places to have rust... but they look fairly easy to repair, most shops in your area should be experts in this minor amount of cancer.
full disclosure, you're looking at maybe 1500...
I'd keep shopping for a welder that'll work on it for less. I'd think under 1K to fix that well, perhaps under 500 if you help, and you treat the metal after the welds are done...

The welder doesn't charge much. I didn't post all the pics. There are really 8 repair jobs. They add up

I need to find a buyer who knows how to weld!

Zacharias · #6 10-02-2012, 11:21 PM

I assume you are in southern Ontario, Graham?

If so that is good news. There is a market for these cars there. Here in eastern Ontario and western Quebec, not so much.

That said, I have to agree that this isn't unreasonable rust for mid to eastern Canada, for a w123. The car is repairable.

Give yourself a bit more time to think about this. Be sure you won't be kicking yourself a few months later, if you do let it go.

Stretch · #7 10-03-2012, 02:59 AM

I applaud your honesty - I get the impression that many people out there would just fibre glass it and paint it black - even on the more structural areas.

Well done that man.

Graham · #8 10-03-2012, 09:06 AM

Quote:

Originally Posted by Zacharias

I assume you are in southern Ontario, Graham?

If so that is good news. There is a market for these cars there. Here in eastern Ontario and western Quebec, not so much.

That said, I have to agree that this isn't unreasonable rust for mid to eastern Canada, for a w123. The car is repairable.

Give yourself a bit more time to think about this. Be sure you won't be kicking yourself a few months later, if you do let it go.

Because welder has a backlog of work, I have been thinking about it while doing prep work, like removing fender liners, stripping floorpans etc. Problem with winter coming, I likely wouldn't be able to get at car after weld repairs until next Spring.

If I needed car to drive, I would go ahead with the repairs - If it cost, say $3000 with me putting in the finishing work, the car would likely be good for say another 5 years. But, if there is someone out there who has the ability and interest to repair the car, I would be happy to see it gone. Just can't see it going to the crushers!

I am in Kingston, so Eastern Ontario. I had three responses to my original Kijiji ad - I will give them a call first before re-advertising.

Zacharias · #9 10-03-2012, 12:31 PM

I sincerely hope that you have luck with the callbacks, if that is how you want to go.

What I want to warn you about, without prejudging those who inquired, is how it unfortunately works in my neck of the woods all too often when you put an ad up.

As soon as you advertise an older car, particularly in the free ads, guys call and are enthusiastic about wanting to see it. When they arrive, however, they start the headgame on every defect... point being they are warming up to telling you the car is only good for scrap value.

I am only saying this so you don't feel gut-punched if you get one or more of these bozos showing up and telling you the car is worth $250. (Voice of experience.)

That being said, it doesn't hurt to engage in some friendly prescreening chat on the phone with prospective viewers over what they know about these cars, what their intentions are, etc. This can avoid you wasting your time waiting around for people to show up who are half serious, or who go to look at every car under $2100, or with those whose first question when they get there is "What's a diesel?"

Hopefully Kingston is better than the Ottawa-Gatineau area, in this regard, and my advice won't be required. Around here it is truly ugly.

300D85 · #10 10-03-2012, 12:49 PM

who did the engine? receipts maybe?

Graham · #11 10-03-2012, 04:17 PM

Quote:

Originally Posted by 300D85

who did the engine? receipts maybe?

It was done by a reputable Toronto shop that specializes in Mercedes.
And yes, I have the invoice (It was close to $7000!)
Plus a book full of other records collected over the 22 years I have owned the car.

Graham · #12 10-04-2012, 07:29 PM

Quote:

Originally Posted by Army

I applaud your honesty - I get the impression that many people out there would just fibre glass it and paint it black - even on the more structural areas.

Well done that man.

I definitely wouldn't do a cover up and try and sell.

But you gave me an idea. Why don't I patch up the non-critical areas and just have the welder fix the rear wheel well structural problems?

In looking at it today, I think I could do a POR/Rivet/FRP repair on the firewall seams and the ends of the rockers. I also think I could do a riveted plate repair on the floor pan to door sill areas (like one guy is doing in another thread)

I have a background is in marine and I have skills in fibreglass as well as in rigging where we used pop-rivets for highly loaded connections. Could do some welding, but would need to update skills and buy equipment.

One thing I like about the rivet repair of the floor/sill join, is that I would be able to POR and even FRP inside of rockers before doing the repair which would not be possible with welding.

Zacharias · #13 10-04-2012, 10:26 PM

I think you have a good idea there.

Based on some other threads I can recall here, others may not be so enthusiastic.

Some are of the opinion that every square inch of the unibody 'tub' assembly should be considered structural and therefore not a candidate for repair other than welding.

I don't agree, and as an FYI the government of the province where I live was unable to demonstrate that in court either, some years ago, when their refusal to accept riveted floor repairs in safety inspections was challenged.

JimFreeh · #14 10-05-2012, 07:46 AM

Graham,

Perhaps this is an opportunity to learn a new skill and pick up some equipment.

It sounds like your new winter project will involve a nice MIG welder setup and lots of weld repair surface prep.

Like painting, rust repair is highly dependent upon the preparation, and no one is going to be more critical than the owner. The prep is not a highly skilled job, so even if you decide to have a professional do the welding you've cut a significant amount of the cost out of the job.

I just spent the weekend with an old friend and we played around with his MIG welder. He's performed many repairs over the years and waxes enthusiastically about how useful it is to own such a tool. He set up some sheetmetal samples in a vise and I practiced welding. It didn't take too long to see real improvement in my technique.

A MIG welder is definitely on my short list for garage tools now.

Good luck!

Jim

Stretch · #15 10-05-2012, 08:04 AM

I think that all repairs to problems like this should be welded. But that's my personal opinion and that doesn't count! You need to check locally what the rules are.

Fibre glass tends to be a big no no (for rust repairs in "structural" areas - and this can vary from country to country) in the parts of Europe that I know of. I was recently informed that in Germany they no longer accept butt welded joints (such is the TUV's confidence in people with MIG welders!) and you now have to make neat lap joint welds that are welded on both sides. That's not the case in Holland (yet).

So in short I think you need to comply with your local rules and regulations.