Deteriorating alloys

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bernieg

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Hi everybody,

I've got a 2001 facelifted SLK230 and the 4 alloys are at various stages of deterioration. By deterioration, I mean that moisture has ingressed beneath the lacquer and started damaging the alloy itself. Close-up it looks like a form 'cancer' is attacking the alloy.

As part of the deal in purchasing the car, the owner got the worst one at the time diamond cut to take it effectively back to new.

Is there any advice for how to stop this in it's tracks or even avoid, or is it simply a price you pay for having a MB car (as well as the rust corrosion which forms on the bodywork - see my other thread).

Thanks in advance.



bern
 

antijam

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With a lacquered wheel, the deterioration you're encountering is impossible to stop permanently. Professional refurbishers rarely guarantee the finish beyond 6 months.

If you want a bright metal finish rather than a painted one, I've found it is better to leave the polished metal unlacquered but polish it with autosol and then protect the surface with Autoglym High Definition wax. I've done this on the wheels of my SLK and it's been very successful.
 

drivencrazy

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W203/2003/2.7L
I had a similar problem with my W203. I had all 4 wheels powder coated in the correct MB colour by Diamond Wheels of Stockport. The appearance is very close to the lacquered, bright metal finish. Only a knowledgeable person would spot the difference and even then only if they were looking for it. Now I can forget about the problem. The bright metal finish is 'more trouble than it's worth'.
 

television

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2002 SL500, 216 CL500, all fully loaded
I had a similar problem with my W203. I had all 4 wheels powder coated in the correct MB colour by Diamond Wheels of Stockport. The appearance is very close to the lacquered, bright metal finish. Only a knowledgeable person would spot the difference and even then only if they were looking for it. Now I can forget about the problem. The bright metal finish is 'more trouble than it's worth'.

That is the only way to go and with the nice bright chrome paints now on offer. MB only use these now on the new wheels.

Clear lacquer has no strength as it has no pigment, any more than the one coat on the body and it will craze at the first frost
 

stats007

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MB like most manufacturers are still offering machined faces on their wheels. They do look very good but as mentioned their is a price to pay in longevity. I now use a product called Jetseal 109 on bare alloy (when polishing rims for example) - much more durable than the waxes or polishes such as Autosol. It isn't cheap however though goes a long way.

Malcolm not sure what you mean by multiple coats of lacquer crazing? Show cars get anything from 10 to 20 lacquer coats with flatting in-between. I apply two coats to wheels.
 

television

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MB like most manufacturers are still offering machined faces on their wheels. They do look very good but as mentioned their is a price to pay in longevity. I now use a product called Jetseal 109 on bare alloy (when polishing rims for example) - much more durable than the waxes or polishes such as Autosol. It isn't cheap however though goes a long way.

Malcolm not sure what you mean by multiple coats of lacquer crazing? Show cars get anything from 10 to 20 lacquer coats with flatting in-between. I apply two coats to wheels.

Am I a little out of date Stats, my data sheets from ICI and Silkens say that for multi coats of clear, 10% of the colour coat should be added to avoid crazing. I know that ICI have now moved out of the car finishing products

I can understand that two coats are needed on wheels
 

stats007

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Given my colour is water-based and lacquer solvent I don't think that would work!
 

joe1972

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Yours are probably no where near bad enough to do what I did with the old 8 hole MB 15" alloys on my w124 e300d (which incidentally are identical to the ones on the 190e, but very slightly smaller than the wife's SL)....

Took all four off, took them to local tyre fitter, all 4x tyres were shot..lots of tread, but seriuosly cracked. so I got him to take them all off and promised I would be back to have 4x new ones fitted in a week or so....

Got back home, and got to work with detail sander!
finished them with simonez alloy 5 wheel spray (which, incidentally found is a perfect match for the top bodywork! lol), finished off with some acrylic laquer. (cellulose is too soft)
Left to harden, then took them back for new rubber and balancing. The fitter didnt beleive that they were the ones he'd seen a week earlier, which seemed a good sign!

Accidentally, I also found that the simonez steel 5 wheel spray being slightly darker silver then the alloy 5 wheel spray is actually a darn good colour match for the bumper and lower trim!!

The other end of the spectrum I know, and the wheels aren't as good as you'd get if taking them in to a pro'.....but for about £20 of paint and a lot of elbow work the car looks 100% better for it....the tyres would have been replaced anyway.

A budget DIY method if the car only cost £300 in the first place ;)


P.S. The £10 replacement fuel sender and 99p instrument cluster (for me to salvage from) arrived yesterday...I now have a working fuel gauge and a non' flickering oil pressure gauge....and all the bulbs now work. a result! (just a shame I couldn't replace the spring for the trip meter...far too fiddly for me and my fat fingers!)
 
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