[exi]

Recent owner of a CPO M850i coupe.

There are a few areas of stained or etched interior, aluminum trim, demonstrated in attached photo, that do not clean off with typical quick detailer interior products.

Seems like somebody used an inappropriate product, but I'm not sure.

Before trying more harsh things, wanted to check in and see what was most effective for folks these days. Formerly spent a lot of time detailing cars when I had the time to do so, but I am not quite up to speed on most recent/best products lately.

(Also a few areas of staining on interior surfaces, like the glove compartment panel, also stubborn to remove; currently preferred products there?)

[John in VA]

It certainly looks like overspray, possibly from glass cleaner. You might try a MF towel moistened with warm water before trying a polishing compound.

[David70]

If it's actually etched into aluminum it isn't coming off. Can you feel it in the material?

If it's a stain and you have used standard cleaning products I will also be amazed if going with something harsher will remove the stain but also not change the finish of the rest of it.

If you use something to polish it out it won't have the same matt finish the rest of it does when you are finished.

[tracer bullet]

Agreed to all the above.

Some (most?) Interior cleaners are water based, and so water tends to get them off afterwards. Next step up could be IPA / isopropyl alcohol - usually safe and can undo things that water has left behind. After that... you might try a citrus cleaner like one of the goof-off versions.

Down the rabbit hole things do get more harsh. Acetone, xylene, and so one are probably going to melt the plastic.

A scratch remover like the Meguiars "Scratch X" could indeed work, but only if there's a layer of clear coat on top that's smooth and can be polished into a little bit. If it is matte on the top coat then yep all you'll do is shine it up.

Worst case consider shopping for interior trim and DIY's on how to get access to it.

[omgzirra_exe]

something acidic like drain cleaner, such as drain-o or a pure vinegar based solution.. wipe and clean off immediately.

works well with water spots stain on windows too.

[exi]

So far, I've tried:

1. Usual interior quick detail products;
2. Chemical Guys APC ("Nonsense"), undiluted;
3. Household white vinegar, with dwell times between 0-30 seconds.

No significant change.

I even spot tested -- very carefully, and with very short contact time -- CLR, which didn't help.

No damage appears done, but the spots remain. Have yet to try the abrasives in hopes I'd find a chemical option and not have to worry about scratches.

Any other product suggestions?

[Raimo5]

Try melamine. If the stains are aluminium oxide caused by chemical etching, then melamine might remove them without altering rest of the surface too much.

[Snave01]

Originally Posted by Raimo5

Try melamine. If the stains are aluminium oxide caused by chemical etching, then melamine might remove them without altering rest of the surface too much.

Mr Clean magic erasers are melamine I think...handy little things

[Raimo5]

Originally Posted by Snave01

Mr Clean magic erasers are melamine I think...handy little things

That is correct. All magic eraser type cleaning foams are made from melamine. I just prefer to use term melamine sponge/foam, as magic eraser is a product name, not a category. But I think for more people it is far more recognizable name than melamine.

[John in VA]

Melamine/magic erasers are abrasive. I read of owners using them on leather seats, steering wheels, etc., but instead of "cleaning" they are actually removing the surface finish (similar to polishing paint, I guess). Can be dangerous in the wrong hands!

[David70]

Originally Posted by John in VA

Melamine/magic erasers are abrasive. I read of owners using them on leather seats, steering wheels, etc., but instead of "cleaning" they are actually removing the surface finish (similar to polishing paint, I guess). Can be dangerous in the wrong hands!

Agree and count me out on using them on something that is somewhat fragile. Scrub a dark colored wall with one and watch the sponge turn the color of the wall as the paint comes off.

If you've ever had a cleaning job that was almost impossible you may have turned to Mr. Clean Magic Erasers. This might blow your mind but Mr. Clean Magic Erasers and generic melamine foam don’t have a chemical cleaner or soap inside them, it’s literally just an abrasive foam that makes them work. Unless of course, you get the kind that specifically comes with soap in it.

https://www.abcactionnews.com/news/n...the-same-thing

[DrVenture]

I won't even use them on my walls. They take a small mark and make it even more of an eye-catcher by altering the texture over a larger area.

One might be useful for lightly scuffing something like plastic, before painting. Or cleaning a sink.