Aluminium Rot Claim - How thick is your paint?

[amwebby]

Having spotted aluminium rot on the bottom of the doors of my CL500 I contacted MB Customer Service, who advised me to take it to a local dealer for an inspection.

I've just done that and, during the inspection, they measured the thickness of the paint with a micrometer. It was significantly thicker on the doors and rear wings, giving an average reading of 140 microns, which they seemed to think was high.

As far as I know there has been no previous bodywork done on the car. The car is Almandine Black, a notoriously hard colour to match, and the colour is uniform all over the car. The car has a FSH with all services at MB approved outlets.

As the front wings and boot are plastic I'm not surprised the reading is different there and really do wonder if there has been any previous work and if this will be cause for MB to reject the claim.

If anyone has any similar experience to share I'd be interested to hear it.

 

[Dieselman]

It does sound exceptionaly high.
Probably the wings have been done before but now the doors are going. The paint will have been blended to cover the join into the old paint.

 

[amwebby]

The paint on my 1979 Aston Martin (just resprayed) is 140 microns but I do understand Mercedes paint is applied less thickly.

The rot is on the door bottoms and wheel arches which, to be honest, is where I would expect any rot to first surface. It also struck me that the main difference was between the aluminium panels and the plastic ones, with the latter being below 100 microns and the aluminium ones being over. Is this normal, or is the micrometer giving faulty readings switching between ferrous and non-ferrous?

If it has been repaired for rot before, what is the drill?

 

[glojo]

As far as I know there has been no previous bodywork done on the car. The car is Almandine Black, a notoriously hard colour to match, and the colour is uniform all over the car. The car has a FSH with all services at MB approved outlets.

Hi amwebby,
I note with interest your wording and of course the thickness of the paint.

Has your car always been serviced by Mercedes-Benz Main Dealers and has it DEFINITELY not had any bodywork repairs?

I am very sorry if I appear pedantic but these questions can be very relevant.

There is always a chance that the repairs might be carried out as a goodwill gesture.

Good luck
John the pedantic

 

[amwebby]

Hi John.

As I'm not the first owner I can't say for certain that there have been no previous repairs, but I have no evidence to suggest there has. The car has been serviced by Main Dealers until the last two, which were MB approved, as opposed to main dealers.

I'm aware these may be sticking points, hence my queries.

 

[glojo]

Hi John.

As I'm not the first owner I can't say for certain that there have been no previous repairs, but I have no evidence to suggest there has. The car has been serviced by Main Dealers until the last two, which were MB approved, as opposed to main dealers.

I'm aware these may be sticking points, hence my queries.

Thanks for taking my post in the spirit it was meant.

I have no personal knowledge of any approved independants that can carry out the servicing of a modern Mercedes-Benz, but living away from big cities might explain that. Does this agent carry out free mechanical warranty work and of course all the free technical upgrades for our vehicles?

I would be grateful if you could let me know the names of the approved service agents as there are a number of folks who have asked this question without getting any replies.

I understand what your saying about the bodywork and it might explain the slightly thicker paint?

Good luck again,
Regards,
John

 

[amwebby]

Hi John,

being the administrator of the AMOC forum I am well versed in the ways of the interweb.

The stamps I have are for Merc-Care - Independent Mercedes Specialist, and MB Motor Group, ditto, both of Leeds.

I assumed Independent Mercedes Specialist implied some form of approval from MB, just as Aston Martin Independent Specialists are certified by AML. Is this an incorrect assumption?

 

[Flash]

I've just done that and, during the inspection, they measured the thickness of the paint with a micrometer. It was significantly thicker on the doors and rear wings, giving an average reading of 140 microns, which they seemed to think was high.

Don't worry - IF your claim is turned down then re-submit a claim else where and try your luck.

I know of a MB approved body shop (you do not need to go through the Stealer) that does NOT measure the paint thickness and they just take digital camera photos of the rust. Your claim will go through for sure...

 

[Dieselman]

Expect the standard paint job to be anywhere between 60-100 microns. The plastic won't have had repairs due to not corroding so is giving the original thickness.
It does sound as if the metal parts have been repainted once already. If the car is over 2-3 years old this isn't surprising.

 

[Flash]

I assumed Independent Mercedes Specialist implied some form of approval from MB, as Aston Martin Independent Specialists are certified by AML. Is this an incorrect assumption?

As long as the service work has been carried out in accordance with the MB service schedule then you are ok. At least you have the service stamps to verify this.

 

[amwebby]

Repainting for rot at just over 2-3 years old does sound surprising to me. The car is 6 years old and, to be honest, I'm surprised at any rot on a car of this quality and age.

 

[Dieselman]

Don't worry - IF your claim is turned down then re-submit a claim else where and try your luck.

I know of a MB approved body shop (you do not need to go through the Stealer) that does NOT measure the paint thickness and they just take digital camera photos of the rust. Your claim will go through for sure...

If it's been declined once by Mercedes Warranty Dept, you won't get it through on a straight resubmission.

It can be that an original submission is submitted on a paintwork code. This will probably be refused if the car is outside the three year paintwork warranty.
If the second, or first, submission is submitted on a corrosion code it is much more likely to be sucessful.

They will only use pictoral evidence on cars that they either know very well or have had previous corrosion claims which will affect a thickness reading.

 

[Dieselman]

Repainting for rot at just over 2-3 years old does sound surprising to me. The car is 6 years old and, to be honest, I'm surprised at any rot on a car of this quality and age.

Sorry to be the bearer of bad news.

Do you not follow the corrosion threads we regularly feature on this forum?

I suggest you don't look under your car or closely at the C pillars behind the wing panels, or maybe they've already been done. (very likely)

 

[Flash]

If it's been declined once by Mercedes Warranty Dept, you won't get it through on a straight resubmission.

It can be that an original submission is submitted on a paintwork code. This will probably be refused if the car is outside the three year paintwork warranty.
If the second, or first, submission is submitted on a corrosion code it is much more likely to be sucessful.

They will only use pictoral evidence on cars that they either know very well or have had previous corrosion claims which will affect a thickness reading.

This body shop is a officially MB approved and they do not measure the paint thickness on any vehicle - DC have inconsistencies and flaws in their warranty dept/process flows. Trust me a re-submission would go through...

If the claim is turned down then the gentleman with the W215 has noting to loose what so ever in re submitting the claim through this particular body shop which will NOT measure the paint thickness.

 

[amwebby]

I looked very closely all over and under this car before I purchased it in August last year. I saw no visible signs of rot or rot repair and, as the owner of a 1979 Aston Martin, I know what to look for!

I might expect rust on entry-level and steel panelled models but not on an aluminium and plastic bodied flagship automobile.

 

[Dieselman]

I looked very closely all over and under this car before I purchased it in August last year. I saw no visible signs of rot or rot repair and, as the owner of a 1979 Aston Martin, I know what to look for!

I might expect rust on entry-level and steel panelled models but not on an aluminium and plastic bodied flagship automobile.

Not being funny here, you should have measured the paint or asked for it to be done.
I would always do it on any prospective purchase given what we all now know.

Your comment about entry level cars corroding is a bit patronising, however Mercedes make no such distinction, as you have found out.
In fact the A class is the most resistant of all the models, and steel is easier to treat properly than aluminium which corrodes nearly as quickly as steel in the right circumstances.

I am not gloating over your corrosion but am merely pointing out that the "flagship" models are just as bad and sometimes worse than the lower end cars, and in all reality there's no reason why they should be any different.

Just because MB make a shed load more profit from a high end model, doesn't mean they spend any more money making it, that's how they make more profit.

 

[amwebby]

Fair points Dieselman. I didn't intend to sound patronising and apologise if it came over that way. My point was more one of astonishment that Mercedes could allow their flagship vehicles, of all vehicles, to be so prone to rot.

I guess my main astonishment comes from having people on the AMOC forum castigate Astons for aluminium rot and other short comings and then to buy a Mercedes (any Mercedes) and find the same faults and worse!

I'm off to buy an FNF Micrometer!

 

[Dieselman]

I'm off to buy an FNF Micrometer!

Make sure you get one that can work on non ferrous material otherwise it's useless on plastic and aluminium.

Seriously on an expensive purchase such as a luxury car the £200 for a paint gauge is money well spent and will throw any dodgy salesman well off course.

I hope it all works out Ok, it probably will as MB probably have a record of repair. That's not being sarcastic, just a fact.

Like you I think it's shocking that these cars corrode but it's a sad fact, they do.
Cars after late 2004 are galvanised but unfortunately that doesn't help aluminium bodies.
If you intend to keep the car get it rustproofed...seriously.

Edit.
Not sure on this but isn't the door frame steel and the skin aluminium, thus causing galvanitic corrosion.
Something is telling me this is a common fault so MB should cover without pressure.

 

[amwebby]

FNF means Ferrous Non-Ferrous. Oh, you knew that. Doh!

Seriously, if it has been resprayed before because of rot, what does that do to the Mobilio cover? Invalidate it?

 

[Dieselman]

FNF means Ferrous Non-Ferrous. Oh, you knew that. Doh!

Seriously, if it has been resprayed before because of rot, what does that do to the Mobilio cover? Invalidate it?

I didn't actually make the link about what you meant by FNF. Doh!.

If the car has already had "warranty" work, that will actually increase your chances of a goodwill claim as the work is finished to MB standard and they take over the warranty of the repair after the first year.

From what I understand it's not a failed repair but a different area of the car in question. The initial repair will have been to the rear wings near the wheelarches and maybe the C pillars. This repair is the doors.

The paint on the doors will be the blending coat.

Your only sticking point might be the non dealer stamps in the service book. the two garages you mentioned are independants and I am sure are not MB approved.

Just persue it and see how it shakes out for now.

At least being aluminium once it is properly repaired and coated over it will not corode again, unlike steel which can have rust deeply embedded in the metal.