Looking to powder coat my oem wheels, any cons i should be worried about,ie reduced strength, increased weight, etc... anyone with experience good or bad would be appreciated.
thanks
ast78

 

The heat treating process in powder coating can change the compound composition of the wheel making it weaker. this is as per my consultant at champion. painting is the way to go. good luck.

 

I painted my OEM wheels from silver to powdercoat black (my car is black), the result was great, I was recommended to go with a semi gloss finish (not full gloss), actually I think the painter was rigth!!, the final result was great!!. the only setback is that after a few track days the finish is not the same, the wheels are losing the nice gloss and depth of color. Maybe the brake dust has stained the wheels during the heat cycle on the track, I think this has not hapenned to original OEM black wheels. I have to poit out that in my case I have been always very careful with my car and always have keed the wheels clean.
just my $0.02

 

Paint will do just fine. The wheels will have to be prepped properly to make the paint stick.

 

Thanks guys. Gus, do you have any pics?

 

should be fine on the wheels

 

You have to ensure the time/temp cycle is kept low and short enough otherwise you will affect the heat-treatment of the forgings. You can powdercoat, if you're careful. We do it everyday. We switched all of our standard colors to powdercoat once they developed metallic powdercoats and got the cure temps down to an acceptable level, so these days it is possible if done properly. We find powdercoat to be more robust, but you get more color options with paint so we still have to use paint for color matched wheels unless we've had a custom color developed in volume (Arctic Silver for example).

 

Mine are powder coated with no problems.

 

Hot much hotter does powder coating get the wheel than the temps from brakes at a track day?

If the wheels are cast and not forged then would painting of powder coating be more durable?

 

What temp. do you powder coat at and for how long on the wheels?

 

I believe the aging temp for T-6061 is 350, so if your pre-baking then cooling, then baking again and again cooling, will this affect the properties or over cure/age the part?

 

i was just about to contact you guys! i got a set of chrome OEM SRT-10 wheels from you guys. amazing set! i'm wanting to go black now. how do i go about that?

 

Exposing a forged aluminum alloy to 375 degrees for 30 minutes can have a negative effect on the strength of the alloy. It will "over-age" the alloy and begin the annealing process. DO NOT DO IT. You will no longer know how strong your wheels are.
Since forged wheels are usually weight optimized for the vehicle, reducing their strength is unwise.
Most wheel companies, and Porsche, will void the warranty on the wheels if you refinish them.
As for chroming, don't do that either. The chroming process causes embrittlement of the alloy, weakening it and making it susceptible to damage under high load.

 

With the greatest respect, this is an engineering question. It is not for refinishers or chrome platers to decide. Many forged wheels have been weight optimized for a specific load on a specific vehicle. That is, the weight is reduced to the absolute minimum required by the vehicle load, otherwise why bother? Therefore, any loss of strength compromises the reliability of the part and its load carrying capability as well. And potentially, the safety of the driver.

The chroming process reduces the ductility and strength of the forged alloy to varying degrees, depending upon the methods used and the specific plating alloy used. This phenomenon, known as hydrogen embrittlement, is well documented scientifically and carefully tested for in aircraft/aerospace components.

Wheels can certainly be designed with chroming in mind. Excess material and mass can be added during manufacturing to compensate for losses in the chroming tank. This thread, however, deals with REFINISHING.
It is our opinion that there are simply too many unknowns in these processes to risk weakening the alloy. Therefore, for forged, heat treated alloys, we do not recommend powder coating except by trained expert facilities with quality systems and Brinell hardness testing systems.
And we do not recommend chroming forged wheels, unless the wheel was designed for this finish.

 

I appreciate your input. But your very general data does nothing to change the facts, or our recommendation.
A cure temp of 375 degrees fahrenheit for 30 minutes will overage the alloy and begin the annealing process. This is not recommended by us, HRE, OZ, Champion Motorsports (who forbids powder coat entirely), BBS and most other forged wheel companies. This also includes the 50 or so forged wheel companies worldwide for which we supply the blank forgings.
Many of these companies will void the warranty for any refinish not done under their control. We don't blame them.
As far as the OEs are concerned, if you refinish or plate a factory wheel and ANYTHING goes wrong, you are on your own: ZERO warranty.
Safety and liability are the issues. We don't know anything about your company, its processes, quality systems or technology. But if a wheel is refinished and then fails in service, or someone gets hurt, we all know who gets served with a lawsuit. The USA has 4% of the world's population and over 50% of the world's lawyers.
Regarding the chrome plating, the issue is really the same. But temperature is not the culprit, hydrogen is. Follow this link:
http://www.misumi-techcentral.com/tt...embrittlement/.
It is an excellent tutorial on hydrogen embrittlement and how devastating it can be to ductility and tensile strength.
We are not being critical of you or your company. We know nothing about what you do or how you do it.
Our concern is knowledge and the safety it brings. We work hard to build wheels that are light, strong and beautiful. When we are going to powdercoat a wheel, we intentionally underage the part, knowing EXACTLY how much temperature it will see in the process. And then we check the Brinell hardness afterwards to be sure that the part is perfect. We think that people who drive $150,000 cars at 150 MPH appreciate the precision.
And we don't want a well-intentioned third party to put all that work at risk.
I hope you understand.

Sorry for the long post.