Beretta.net

is this oxidation? this is the center cap and all of the wheels have it. i have tried cleaners, degreasers, rubbing compound, sand paper, and even aircraft stripper on a small spot. i want to paint the wheels later but i want the surface to be prepped perfectly.

if you tried all that then im sure you already ruined it..especially sandpaper.. are your rims aluminum/polish aluminum?

aluminum gtu wheels.

the whole surface of the rim is covered in the black(some are yellow) splotches. i plan on painting or plasti dipping. what ever it is has started pitting and leaving a texture which is why i tried light sandpaper. the cleaners, rubbing compound, and chem stripper did absolutely nothing to the surface. nothing recognizable any way

Sounds like oxidation got through the clear coat and into the aluminum and has turned into corrosion on the aluminum surface. The only way to get through it is to sand through the corrosion into good aluminum. But, you've gotta do the whole wheel, and then paint and clearcoat before you run the wheel again. It's tough, and a lot of work to make it look good. If it's that bad it's probably better off in the hands of a professional wheel refinisher.

Is there supposed to be a picture in this thread? I think it would help with identifying what it is...

refinishing a wheel isnt easy, i used to work for a shop where we did them, we'd dip them in an acid to remove the paint/clearcoat, powder coat, ect... and sandblast them with little plastic beads(sand would have destroyed the alluminum), paint them, file the lips and they'd look like brand new again...

my bad. here it is

Its oxidation, aluminum that isnt polished or have clear coat/ a wax of some sort on it will oxidize. The oxidation is like rust, it will eat the metal aluminum away, your problem might be how deep it is, if you sanded ect and it didnt come off than youd have to sand more to remove the pitting than polish ect..

^ Only thing is though, if he sands too much he will mess up the light machine finish that the GTU rims have, then he's stuck polishing them completely smooth to make the finish match unless you can find a way to recreate the factory machine finish pattern, hmmf, unlikely...

GTU rims should be clear coated, but thats where the clear has cracked and its either oxodized below or brake dust has made its way in and under the clear. Either way yes the rims have to be refinished if you want to get rid of that.

kinda looks like fallout damage

GM does this all the time and it's retarded. They machine and then clear coat wheels...but the machined surface doesn't have the bite for the clear to stick.

Since you are painting them you can fix this pretty easily. A primer and then paint and clear should fill in the oxidation pits if they are small enough after you scuff the wheels for good adhesion. Or you can powdercoat them. They would have to be pretty serious craters to show after powdercoating.