B-tsai

Sup all

I'm getting a bit tired of looking at my dingy/rusting running board plates and was wondering if anybody has considered refinishing them?

Mainly, I was thinking about having them chrome plated or powder coated.

Powder coat would likely be silver, or just black (my car is black w/ black wheels).

Any suggestions on what the costs of coating are these days?

TIA.

roadrutz

How would you avoid damaging all the little rubber inserts?

B-tsai

I thought that the rubber nubs were a separate piece from the actual top aluminum cover... I envision perhaps having to enlarge the holes to accomodate the rubber nubs poking through.

jralstondr

you can use any good aluminum polish on the running boards and they will look as good as new.

roadrutz

Pure aluminum reacts very easily with water in the air, particularly in the presence of road salts, forming aluminum oxide, a greyish, powdery substance. I think that is what people mean when they talk about "rust" on the running boards. (True rust is a reddish brown oxide of iron, not aluminum.) So I can't imagine any manufacturer leaving any aluminum part uncoated. I believe the ML running boards are treated with some kind of plastic protectant. Where that protectant wears off for any reason is where the underlying aluminum oxidizes. If you use an aluminum polish on it, you will simply wear off the protectant faster and hence make the aluminum even more likely to corrode. Which leads to a vicious circle in which you have to keep cleaning the aluminum as it keeps oxidizing ever faster.

Aluminum oxide is unsightly but, unlike true rust, it actually protects the aluminum underneath as it stops water from getting to the aluminum, so it really shouldn't be cleaned off. That is why you never polish an aluminum boat -- the oxide that forms on the surface protects the hull from further corrosion. If you keep cleaning it, it gets thinner and thinner and sooner or later it wears away, which, in the world of boats, is generally considered to be a Bad Thing.

The running boards aren't pure aluminum, of course, but an alloy. But even so, I would think it best not to use polish on them any more often that you absolutely have to.

B-tsai

Well, I tried to polish the boards tonight.. but stopped because it's gonna take me forever to get around each nub and to scrub out the extra dark spots/rust dots.

I'm instead going to try uninstalling it... and then just work with the aluminum cover plate itself... hopefully the nubs really are a separate piece underneath the aluminum.

Here's a pic of how bad my boards are.. and the little bit of section that I polished tonight.


Edit... crap.. I don't think the rubber nubs are separate from the aluminum. I think I'm going to try polishing with a brush instead of a towel to get faster results.

GateKeeper

Just wondering.......

do you live near a railway track ?

I have been told this type of (rust spots) are enviromental fallout, and are even worse if you are near a railway track, due to the fact as the trains go by, they kick up metal dust, from the wheels and track contact, this becomes airborne and settles on our cars, which in turn looks like the cars are rusting.....

Look closely at the rest of your vehicle and see if you notice these rust spots anywhere else, you will find them even on the plastic bumpers, to remove from the body of the vehicle I hear a good clay bar session is in order and will remove those contaminants..

B-tsai

I just bought the truck 2 months ago (Ex-leased vehicle).. so I don't know much about the history other than the carfax and MB maintenance reports.

No other rustspots on the body, though the muffler's look a little tinged in color.

Now that I think about it... I think I'm going to have the bottom of the car coated in some kind of rust-proof application if I can find it for cheap. Maybe install some kind of sacrificial anode or something.

GateKeeper

Was this a private deal, or from MB

perhaps the truck was detailed, and this might be why you don't see any of the rust spots on the rest of the truck

I wish I paid more attention to how the rubber nibs are attached to the board, I just installed a set of boards on my ML, but did not bother to see or look at this, perhaps if you take them apart you might be able to pull off all the rubber nibs and it will make cleaning the boards much easier.

I am sure I will fall into the same situation soon, I had these rust spots on my BMW X5 as well, replaced by BMW once, but they would not do it a second time, didn't matter it went back after the lease was up anyways

roadrutz

Be careful! Mercedes specifically recommends against aftermarket rust-proofing treatments, so your corrosion warranty, if you still have one, may be invalidated if you go ahead.

I don't like the treatments as they often plug up drain holes, thus making rusting problems worse than they would be without the treatment.

I would hazard a guess that your running board discoloration is some kind of environmental thing -- maybe acid rain. Or perhaps the previous owner tried cleaning them and removed the protective covering.

etpos73

Did you ever try removing them? I'm looking at a set of black wheels and think that powder coating my running boards black might look better.

B-tsai

I ended up taking them to the detailers to be power polished for $15... turned out much better, but they missed some spots.. likely it'll darken out again after a year..

etpos73

Thanks!