Alloy Wheels-Paint or What - PeachParts Mercedes-Benz Forum

haasman · #1 03-22-2003, 12:19 AM

Note: for some time difference reason, the original post is below my response

_______________

From the Detailing section, Wheels and Tires, a posting makes the following suggestion:

"Try the search function first and get creative. Try "painting rims" or "refinishing rims" or "refinishing wheels", etc."

Keep us posted,

Haasman

oldsouth · #2 03-22-2003, 01:20 AM

On a 1995 S-Class 140 Series, are the alloy wheels painted or what. Looks like some sort of paint to me. Mine are showing signs of wear in the holes. Is it acceptable to sandblast and powder coat the wheels if they are painted? Or does this weaken the wheel. What is the best way to get them back to factory new looks?

Kestas · #3 03-22-2003, 11:02 AM

Sandblasting and powder coating should not weaken the aluminum alloy unless overly aggressive sandblasting seriously thins the section (hard to do) or excessive temperatures (>350°F)are used to bake the powder coat. In fact, sandblasting imparts a mild strengthening effect on the metal surface by its shot-peening effect.

rdanz · #4 03-22-2003, 11:29 AM

I have a 94 which I think are the same wheels 8 hole. they are polished with a clearcoat. Spray wheel cleaners ruin the clearcoat .
One way to redo is to have the wheels media beaded and then polished, which will make them look better than new almost like chrome.
Another way is to sand and paint them which looks like the newer wheels on MBs but I prefer the first the only problem is that you have to keep up with the polish about once a month. Unless you clear coat them again which dulls them down somewhat.

The wheels can be beaded with the tires on which is a plus.

suginami · #5 03-22-2003, 11:56 AM

I have 1995 E-class 8-hole wheels on my car that I purchased used and had to have them refinished.

The 8-hole wheels on W124's are painted w/ a clear coat from 1992-1994, and machined w/ a clear coat on 1995 only.

Before having my wheels refinished, I looked at the 8-hole wheels on the W202 C-classes and W140 S-classes, and found that Mercedes seemed to follow no particular pattern. Some cars had silver painted wheels, and some had machined wheels. It wasn't as if the older cars were silver and the newer cars were machined.

Just to clear up a point, none of the 8-hole wheels are "polished". They are actually machined on a CNC (a large mill). If you look very closely at the wheels, you will see small lines, or grooves, around the wheels, that look like the lines on a vinyl record.

If you want to get polished wheels, you first get them machined, and then they polish them with a diamond wheel / buffer. Polished wheels are so reflective that they look like a mirror - much the same as chrome. The problem with polishing is that the surface is so smooth, that the clear coat won't stick.

If your wheels are painted silver, you really couldn't machine them. The wheel refinishing guy told me that if you stripped the paint off, you would have a dull, alloy finish. Wouldn't be appropriate for clear-coating. You'd be looking at a cast alloy finish that you could paint right over if you wanted to paint, but if you like the machine look, you'd have to send them out for machining on a mill.

Further, whether you re-machine or re-paint, the wheels are still vat-dipped chemically stripped. He couldn't imagine how you could effectively strip them otherwise. Didn't recommend trying it at home.

Fwiw, they only powder coat the clear coat on machine finished wheels as powder coating leaves a fairly dull finish.

If they paint them, the refinishing guy told me they use a urethane based spray-on paint, and they don't always clear coat over paint. It depends on what look the customer wants. If they want a brilliant silver finsih, then they don't clear coat. He says the urethane is so durable that the finish won't come off. If the paint doesn't need that much gloss, then he clear coats over the paint.

joe p · #6 03-22-2003, 12:11 PM

Send 'em to Ruiz and let him polish 'em out then clear coat them.

Get that 208 look on a nicer looking wheel. (I like the look of polished alloy over chrome any day)

In all seriousness I think the polished wheel set off a car but, a nicely detailed set of painted and clearcoated ones look nice as well. There is nothing that brings the look of a car down like crappy wheel finishes.

Joe

GregS · #7 03-22-2003, 04:04 PM

I saw a w115 coupe at the Carlisle, PA foreign car show last year that had painted/clearcoat inner wheels with a polished outer rim. It looked very unique and very classy. I never saw anything like that before.

GregS
'84 300D, 173k
'90 300CE, 162k

rdanz · #8 03-22-2003, 06:21 PM

suginami

My brother owns a body shop and they Media blast and paint or polish wheels quite often the paint is silver paint with a clearcoatand comes out quite nice. The polish is done with a product called semi chrome and a buffer yes the polished wheels can be clearcoated by using a spray base coat that sets up the wheel for clear you can get the retail brand of this at Pep Boys.the only thing is if you use the clear some of the shine is lost.

Been there done that!

oldsouth · #9 03-22-2003, 08:32 PM

After closer inspeciton of my wheels, I believe they are polished and clearcoated. Just doesn't look like paint to me, but there are no machine lines around the wheel. I will see about getting a close up photo and posting it.

rdanz · #10 03-23-2003, 04:10 PM

Old South
In a cpl of week my brothers going to fix a 95 wreck he's doing the wheels also. I will try to get before,during and after pics
The wheels are being beaded and polished.

Steve Gutman · #11 03-25-2003, 01:44 PM

After refinishing my winter set of old Bunt Cake rims I have learned that it is quite a major job to sandblast rims down to the metal. It cleans up any areas that are corroded easily, but if you want it perfect, it takes forever. Maybe I needed a bigger machine but the cabinet was 3x3x4'. I wound up dusting them off with the sandblaster and painting with aluminum paint. There are blemishes but they look good from 2 feet away.

I have a set of 1985 AMG rims that were originally painted then turned on a (CNC) lathe then clear coated. There was corrosion. I had them stripped, painted, turned (the bespoken lines or machining marks) then clear coated. The problem is that when the wheels are forged there is a layer of higher density on the surface. By the time they are turned at the factory then turned again at the refinisher it has removed the higher density layer and exposes a more porous surface, which show up as microscopic bubbles. They look 1000% better than before but it is far from perfect. I do not recommend having rims turned for this reason. Have them polished and/or painted.

Kestas · #12 03-25-2003, 01:51 PM

Exposing microporosity in aluminum can turn a rim into a leaker. Oftentimes, leaky aluminum castings or forgings such as rims, intake manifolds, and heads can be salvaged by epoxy vacuum impregnation techniques - usually done at the manufacturing facility.

rdanz · #13 03-25-2003, 03:08 PM

NEVER I repeat NEVER sand blast alum. wheels Media beading removes the clearcoat and if painted paint also without damaging the wheels. The place we use has a room that he beads cars with and removes every bit of paint without damage. He does all four wheels with the tires still on and come out beautiful.

oldsouth · #14 03-25-2003, 03:31 PM

Rdanz, where are you located? Close to Louisiana?

Below are some photos of one of the wheels. Not bad but not perfect.

oldsouth · #15 03-25-2003, 03:32 PM

Close-up