No **** Sherlock. But did you know the stock wheel is covered in a UV-cured powder coat that only requires an oven temp of 230*F (110*C)? How about a little more research before you spout off the painfully obvious next time?
You are assuming that the person powder coating the wheels knows wtf they are doing. If the heat is applied and removed gradually, everything should be fine.

The problem is that many places have an oven that is barely big enough for one wheel, so they pre-heat the oven, stick the wheel in, and as soon as it's done, they yank the wheel out and let it cool at room temperature. This way they can get each wheel done 15-20 minutes faster because they don't have to wait for the oven to heat up and cool down each time. It also saves on their electric bill. So what you get is a wheel that goes from 70* to 375* and back to 70* in a matter of about 10-15 minutes. And that's if you use a consumer-grade powder that can be cured in a conventional kitchen oven. Not super-durable, but definitely easy to apply and easy on the wheels.

What they should do is let the wheel and the oven come up to temperature together and then turning the oven off and letting the wheel cool as the oven cools.

And FYI, some professional powder coating is cured in a high end Infrared oven and the part goes from 100* to 475* and back to 100* on 90 seconds. Not an ideal situation for a cast aluminum wheel.

Powder coating is too general and vague of a term and everyone ASSumes they are all the same, and unfortunately saying all powder coating is the same is like saying all paint is the same.

 

Very good info here. What about the forged BBS's on the MR's though ? Do they have the low temp coating too? Being forged and having denser grain structure not a porous casting, I would think the heating process would not affect them or very little any ways. You'd still want them done heated and cooled down properly though as per above.

milburn

 

Actually, forged wheels are MORE sensitive to the high heat of powder coating than cast wheels. The heat can weaken the structure of the forging. Wheels are forged by being heated while under thousands of tons of pressure. This aligns the grain strusture of the aluminum and makes the wheel much stronger. And if you heat the wheel without that pressure, it can allow the grain structure to "relax" and make the wheel resemble more of a cast part than a forged part.

And since forged wheels are so much stronger than their cast equivalents, they typically have thinner spokes and rims. (This is why they are lighter than cast wheels. Because they can be thinner and at the same time, they can also be stronger.)

That's great until you weaken the structure of the wheel. Then you are left with spokes that are only as strong as a cast wheel, but much thinner than they otherwise would be.

The melting temperature of aluminum is around 1220*F, which is well above the 400* or so seen by a powder coating process. But the problem is that the Aluminum that wheels are made of is not pure Aluminum, it is an alloy. Almost every aluminum part you have ever seen has been an alloy. Pure Aluminum oxidizes or "rusts" as soon as it is exposed to the atmosphere.

As such it is the elements composing the alloy that effect how it reacts to high temperatures and cause it to be compromised by the powdercoating process. 6061, which is one of the most common alloys used for wheels, has Silicone, Iron, Copper, Manganese, Magnesium, Cromium, Zinc, and trace other metals in it. It is used because it's easier to machine than 7075, which is a lot stronger than 6061 once heat treated. 6061 is usually heat treated, but there is a big difference between heat treating and powder coating.

 

I guess you win since you got the facts. But the truth is, that it is not common for people to run into problems. I am sure if we started a new thread, with a poll, we will confer the same thing being that you dont come across as many issues (if any) for the amount of people that have done this (not just on evo's but for millions of other parts)


So in the end, its like lowering your car on a cheap set of springs. Many people go thousands of miles without seeing a single problem with struts or shocks, while you have the Anti-Springers that know billions of evo's that blew out stock struts and they say they are the devil.

 

Nah man, aftermarket wheels look cool on the car, not stock. Spend the money on new ones, believe me.

 

Exactly. If you're not hard on your car and use it more as a commuter vehicle, then you'll probably never have an issue. And if the wheels are cheaply cast to begin with, you'll likely never have a problem either. BUT if you have forged (Volk, ProDrive, BBS), or very high-end cast wheels (Advan, OZ, Weds) or drive your car hard and/or race it occasionally, then that's a roll of the dice I would say is just too risky.

 

100% agree. The only question now is why do people waste thousands of dollars to sand down volks and temp them flat black

To answer the other dudes question about just buying wheels, I eventually will, but I am more worried about making my car fast. Sooner or later i will get a nice set of wheels, but modding money is just not there.

 

Just prep the wheels well, and use dupli color wheel paint ....tough to beat for the cost http://www.duplicolor.com/products/wheel.html

My good friend did this on his track (o.e.) wheels for his M3 and they turned out real nice.

 

definitly different i like it though

 

I say do it. It's your car, who cares what other people think.