does powder coating actually weaken a wheel?

[twastheglow]

Before I even begin my post I want to mention that I'm making this thread to try to have an intelligent conversation on TST. That seems to be quite difficult on this forum lately so please help me out here. I don't want this to become a pissing match...period.

With that being said, I wanted to discuss what people's opinions are on whether powder coating a wheel can actually weaken the wheel through the baking process.

I've done a lot of reading on the subject and have heard both sides of the arguement. Unfortunately for me I'm not educated enough in the science behind forging and heat treating.

The theory is that baking a wheel (from what I've read apparently forged wheels seem to be more susceptible) in the powder coating process can weaken the alloy by changing the molecular structure. Now, also from what I've read it depends on many different variables; such as the wheel construction, how the wheel was heat treated, as well as what the powder coating oven temperature is set at, ect.

I did find this article among many that I read that I found interesting...

http://forums.nasioc.com/forums/show....php?t=1793970

This is of interest to me because I just recently had to decide on how I was going to go about painting my wheel centers. Originally I was going to have them powder coated and be done with it. But the more I looked into it and read about it, the more I started to wonder if that's the route I should take. The major downside to having rare wheels is replacing parts (lips, barrels, centers, caps, etc.) can be very difficult. And I'm not sure I could even replace one of my centers if one was damaged. Since my centers are forged the last thing I wanted to do was possibly weaken them. As a result I decided to have them painted at a body shop. But I decided that for a couple other reasons too. Firstly, although this paint wouldn't be nearly as durable as powder coating, it's a lot easier to touch up. I just need to buy some touch up paint in the color code of what I was using. Secondly, I already had a car color in mind that I wanted them painted, so obviously that's easy to match when you're having them painted by a body shop. And lastly (this wasn't a deciding factor in my decision, but it was nice after the fact, LOL) it was pretty cheap.

I wanted to get people's opinion on the subject. And I am in NO WAY putting powder coating wheels down. I just decided to take my wheels in a different direction. That also doesn't mean I think powder coating wheels is a bad idea either. Like I said, I'm not educated enough to determine that. So again, don't make this a bitch fest please.

[rickhigginshtbr]

interesting... never thought of it. So many variables though... and by reading the thread you posted, it seems as if you should be fine (with most wheels) if the temps for powder coating doesn't exceed too far over 400 degrees for only an hour. The main variable is, like stated in that thread, what material is the wheel actually made of? There's no real fool proof way to find out, even the manufacture may not know 100% what percentages of one metal to another it is.

In other words, do what's comfortable for yourself. If your afraid of the wheel weakening... paint them. If your not, powder coat them. The specific color your going after would lean me right into painting as well.

[DaBombDiggidy]

In personal experience i haven't seen powder coated wheels fail. Yes they may weaken them slightly, but if it was as big of a problem as some threads make it to be, i am sure the people would stop powdercoating wheels. I feel like if they would need to replace them they would loose out on alot of profits re-investing into replacements. Paint on the other hand looks good if you take the 5-6 hours to do it right, but after a few months 80% of the time it chips. It would be cool to see someone on here who does powder coating chime in!

[twastheglow]

Originally Posted by rickhigginshtbr

interesting... never thought of it. So many variables though... and by reading the thread you posted, it seems as if you should be fine (with most wheels) if the temps for powder coating doesn't exceed too far over 400 degrees for only an hour. The main variable is, like stated in that thread, what material is the wheel actually made of? There's no real fool proof way to find out, even the manufacture may not know 100% what percentages of one metal to another it is.

In other words, do what's comfortable for yourself. If your afraid of the wheel weakening... paint them. If your not, powder coat them. The specific color your going after would lean me right into painting as well.

I thought it was an interesting point too.

But yeah, the number of variables is pretty high. I think that has a lot to do with why it hasn't been proven/dis-proven. *shrugs*

Originally Posted by DaBombDiggidy

In personal experience i haven't seen powder coated wheels fail. Yes they may weaken them slightly, but if it was as big of a problem as some threads make it to be, i am sure the people would stop powdercoating wheels. I feel like if they would need to replace them they would loose out on alot of profits re-investing into replacements. Paint on the other hand looks good if you take the 5-6 hours to do it right, but after a few months 80% of the time it chips. It would be cool to see someone on here who does powder coating chime in!

Although I haven't seen any fail either, I don't see how you could prove it was powder coating that caused the failure. See what I'm saying? A failure of a stock wheel is just a failure...a failure of a powder coated wheel could just be a failure from the wheel itself...or it could be the powder coating process; how could you tell?

I also think where you get your powder coating makes a HUGE difference. As mentioned in that thread I think, the oven temperature has a lot to do with it. And maintaining that temperature is only as good as the oven used. I would assume most professional powder coating companies have high quality equipment/ovens.

[dangerousatom]

No way does it weaken the wheel. Your only looking at temps of 375-425 to get the PC to flow out.

If it did none of the Indi-Drif-Drag-AutoCross-Rally teams/cars would use them

[rickhigginshtbr]

i think the only true way to see if it's true is to take 2 identical wheels, paint one, pc the other... and stress test them on a machine.

Where's myth busters when we need them?

[twastheglow]

Originally Posted by dangerousatom

No way does it weaken the wheel. Your only looking at temps of 375-425 to get the PC to flow out.

If it did none of the Indi-Drif-Drag-AutoCross-Rally teams/cars would use them

Again, I don't know that it does or doesn't. But I guess what's becoming more apparent the more I read about it is that there doesn't seem to be any way to prove it either way. Your basis for thinking it couldn't weaken the wheel is because someone else doesn't. So who's to say that person doesn't think it would weaken it for the same reason?

I'm just trying to play devil's advocate here. In my HONEST opinion, I don't think I would put enough stress on my wheels on the street for it to matter either way.

[twastheglow]

Originally Posted by rickhigginshtbr

i think the only true way to see if it's true is to take 2 identical wheels, paint one, pc the other... and stress test them on a machine.

Where's myth busters when we need them?

Actually, I agree.

I would honestly love to see independent testing of both cast and forged wheels painted and powder coated put through stress until it fails. I would also be interested to see how both cast and forged test after being subjected to different amounts of heat.

[vdcoff]

This is very interesting because I am thinking about getting my wheels powder coated when I get them. But I know a guy that does excellent paint jobs and he would do an amazing job painting my wheels, and it would be cheaper. Decisions, decisions

[dangerousatom]

I say no because of the testing and trust the company's and race teams put into their wheels as a component of a high end $100k-million dollar machine. If it can actually be proven that it does, I would not be surprised if the parameters required to get them to fail are far beyond even heavy use and abuse of a race/rally situation.

[vdcoff]

Originally Posted by dangerousatom

I say no because of the testing and trust the company's and race teams put into their wheels as a component of a high end $100k-million dollar machine. If it can actually be proven that it does, I would not be surprised if the parameters required to get them to fail are far beyond even heavy use and abuse of a race/rally situation.

I agree

[twastheglow]

Originally Posted by dangerousatom

I say no because of the testing and trust the company's and race teams put into their wheels as a component of a high end $100k-million dollar machine. If it can actually be proven that it does, I would not be surprised if the parameters required to get them to fail are far beyond even heavy use and abuse of a race/rally situation.

Eh, I'm still not convinced but you very well may be right.

I will say however that I have seen wheels fail during motorsporting events. So if those wheels became even weaker than what they were stock, it would be quite relavant.

[twastheglow]

Dangerous, you do have a pretty compelling point though. Too bad we couldn't speak to those teams to get their opinions.

[sean3]

Do race teams powdercoat their wheels?

I've seen a few broken PC'd cast aluminum wheels (online, not in person). Never saw a conclusive answer but I'd rather not risk it. For street use I don't see it being an issue though.

[twastheglow]

Originally Posted by sean3

Do race teams powdercoat their wheels?

I've seen a few broken PC'd cast aluminum wheels (online, not in person). Never saw a conclusive answer but I'd rather not risk it. For street use I don't see it being an issue though.

I was literally just about to post that question. Great point.

[dangerousatom]

I too have seen wheels fail in the middle of a race lap. I dont recall any of them being a steel wheel, only aluminum/magnesium wheels. I also dont know of any wheel manufacture that ultra-sound scans their wheels after forging to look for microscopic anomalies. Such as micro fractures, air pockets, or metallurgical flaws within the wheels construction. These IMO are there in every wheel and lead to the failures, but it take the rite circumstances, fatigue and environment for all parties to come together to create a failure.

Originally Posted by sean3

Do race teams powdercoat their wheels?

I've seen a few broken PC'd cast aluminum wheels (online, not in person). Never saw a conclusive answer but I'd rather not risk it. For street use I don't see it being an issue though.

Hence the reason they are soo much cheaper than forged wheels. I know there are tons of flaws in cast wheels, nad many are not microscopic.
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[twastheglow]

Originally Posted by dangerousatom

I too have seen wheels fail in the middle of a race lap. I dont recall any of them being a steel wheel, only aluminum/magnesium wheels. I also dont know of any wheel manufacture that ultra-sound scans their wheels after forging to look for microscopic anomalies. Such as micro fractures, air pockets, or metallurgical flaws within the wheels construction. These IMO are there in every wheel and lead to the failures, but it take the rite circumstances, fatigue and environment for all parties to come together to create a failure.

I definitely agree with that. All wheels have flaws, you just have to look harder for them with some.

BUT, what I'm wondering is if the baking makes those small flaws larger...not in physical size necessarily, but in potential for becoming a larger problem.

I also don't think powder coating a wheel multiple times would be a good idea either. lol

[twastheglow]

And dangerous, you obviously don't think powder coating is a problem...do you think that with both cast and forged equally?

[dangerousatom]

You Sir need to talk with a Metallurgists with an Engineering Degree to get your answer

[twastheglow]

Originally Posted by dangerousatom

You Sir need to talk with a Metallurgists with an Engineering Degree to get your answer

hahahaha Yeah, I agree. I wasn't expecting to get an actual real life answer on this forum. I kind of just wanted to open it up for discussion and get a feel for people's opinions on the matter.

But on a serious note, I am interested in knowing the answer...assuming there is one. I wouldn't know the first place to find someone to speak to. lol