Today i had the tires taken off my BBS wheels to get powder coated. i need opinions on if i should go simi flat of just flat. (i think they call it Solar black)
fyi the flat matches the plastic fender trim and the tires, but my side repeaters and other painted black stuff is semi flat black
OH, and on another forum, most people are saying that flat will look rattle caned and too cheap, so i should go for a semi gloss....

 

Are you going to go solid color or leave a polished lip like on the Red/black MINI in your las pic?

 

solid color

 

umm well why not get them painted the color of your MCS?

 

I don't mean to rain on your parade or anything, but just want to be sure - are you are aware that powder coating weakens the wheels? I just happened to have seen this topic come up on a forum recenty and as it turns out the high heat required to powder coat used on finished wheels effects their integrity (the extent and potential damage varies based on the wheel from what I can glean, and I imagine forged vs cast makes a diff too). Anyway, I don't know if it matters to you, but if it does you might want to search around about that and maybe ask the manufacturer or dealer about the temps if it does.

 

Semi gloss, polished lip!

 

I like them the way they are, but that's because I'm not a fan of black wheels. I'm sorry

 

Semi will be easier to take care of than flat.

 

Semi will show less brake dust that flat, and it will be easier to clean too,

BUT as previously stated, by BAKING on the powder-coat you will be annealing the wheels (which means you will make the metal more flexible, or prone to dents)... doesn't matter if they are forged or cast, as annealing will remove any work-hardening from forging...

DO NOT USE THESE WHEELS for any Track work or even Auto-Cross (you probably will not pass Tech anyway with them...)

Have you looked in anodization to change the color?

 

well im an idea man, i thrive on enthusiasm.
I'll definately be using these wheels on the track and in Autocross. If they break they break. Im really not worried about it, and im sure ill pass Tech inspections. Anyway i really wanted to go flat but with the maintenance and possibility of a cheap look, ill probably go semi gloss.... or bright blue or green or something like that

 

If they break while your on the track or on the freeway that might be a bigger deal than you think-possibly fatal. I understand youre desire to have a certain look but please becareful that you are not creating an unsafe situation for your or your MINI. As for color opinions-I like them the way they are or maybe black anodized with a polished lip

 

If they break they break....

Please do not get on the same track as me. They are not going to call you on the mobile and say in a nice polite voice; " Hello sir, I think we will break now, please slow to a crawl or stop" It will more likely be a catastrophic failure at high speed at an apex point where the most stress is on them. IF you are lucky it won't dig in and flip the car over. At the risk of being flamed this is a very irresponsible stance you are taking. I do believe people should not alway be protected from themselves but in more then one forum you have been told that powder coating these wheels will weaken them. Take them to a proper wheel refinishing shop and have them painted. Wheels America will do the job right and they are somewhat local to you.

 

I've been powdercoating things like bike frames and their rims for years without problem and had never heard of this issue with weakening the metals, not that I asked or use places that seem like my safety is their number one concern...

Is there something different about rims as the powdercoating process is specifically used on metal surfaces. Makes me wonder why a process that weakens the material would be so popular for a variety of applications....

I saw the post on the high heat being responsible for this, but I would think this would effect almost anything powdercoated.

 

BBS's are forged wheels, when you powerdercoat them the heat will anneal the metal. This ends up softening the metal.

Other wheels that are not forged are safe to powder coat.

Again, this warning is for forged BBS and other forged wheels. Wheels that are cast are safe to powdercoat.

 

The microstructure of aluminum will be affected at a much lower temperature than steel. Most powder coats have a cure temperature in the range of 400 deg F which will do essentially nothing to steel but can make a real difference in aluminum. According to my ASM aluminum handbook here, reheating many grades of aluminum to 400 deg F will reduce strength- some grades can handle a short stay at 400 deg (like 15 min), while others can not. There are some low temp cure powders out there (I think in the 200-250 deg F range) and my guess is that low temp powder is used by OEM's on wheels- thats purely speculation on my part.

Jason

 

I'm no metallurgist but I think it has to do with a several things - the fact that the wheels are made from an alluminum alloy and they ea are finished at the factory at different temps depending on what the manufacturer deems as optimal and that it then becomes 'aged' and weakened by exposure to re-curing at high temps. Since auto wheels handle such heavy loads I'd think that they more apt to be stressed enough to fail from any weakening then some other applications - no idea how it might manifest, cracks around the lugs or spokes perhaps? I've also heard that the after production surface powder coating may start to crackle since it expands/contracts at a different rate then the aluminum wheel beneath it - but that sound like just a cosmetic thing.

 

Better answer I had the reply window open while this was being posted

 

I'm not too sure about that-

Even looking at a A356 cast aluminum, the aging temperature can be as low as 300 deg F-

I'm not an expert, but I'd not feel comfortable with a set of cast aluminum wheels that were cured at standard powder coat cure temps.

Jason

 

so you think that i can just get them painted? will that hold up.
at least i'll look good with sweet black wheels if they do break and i go rolling around a corner. jk
im not trying to be wreckless here, but the wheels are definately not staying the way they are because i already preped and sanded them. If paint is an option that will hold up, i'll do that, or if there is a low temp poder coat, id go that route too. but some people are telling me that it really is not a very big deal. guess ill have to call some podercaot places and get some more input

 

I suppose its 'not a big deal' until it is - things may not happen to people with some circumstances with some types of wheels and usage whereas someone else may not have the same luck (aside from the individual wheel and powdercoating street vs track use could make all the difference). If it were me I'd contact the manufacturer or someone associated with them vs a powdercoater just because they will be more educated about your specific wheel (and I imagine the powder coating people might be somewhat biased..).

 

back in the day I had the cradle frame of my BETA trials bike powder coated.

Now this was a trials bike so it took a serious beating in it's time. Prior to the powder coating I had no issues with the frame. It was inspected before it went it to be treated and it looked perfect.

About 8 months and a few events after the treating the frame developed a crack right around the head where the forks and triple clamp meet up with the frame. I had to have the frame re-sand blasted and re-welded. When it came time to re-finish i just had it painted black. After that it was never a problem.

As i said totally different application... and not sure if it even applies. If you've ever seen a trials event you will know the kind of drops and crashes this bike would have had to sustain so...

that's my .02 fwiw.

 

If someone is heating a wheel in powder coating to the point of weakening the wheel you need to find a new pc shop. That's bunk.

I've done wheels for over 20 years as wel as hundreds of calipers and other aluminum parts. The process does not take temperatures high enough to do damage. I'd have melted many a rubber seal on a caliper if it did well before damaging the body.

The biggest problem with pc wheels is having the nuts come lose or the hub face slip on the hub. Scuffing both and or taping the lug seats prevents this. The pc will compress and act as a lube if you don't take action on that area first.

 

Did a little search and found a similar topic on another forum that has some interesting info in it:

http://forums.nasioc.com/forums/show....php?t=1263238

There is no shortage of opinions and experiences when it comes to powder coating wheels - I guess the bottom line to me would be when there is some real testing to determine what does and does not age or weaken the wheel and over how much time/punishment any issues might surface, etc. Realistically I don't know if any tests could cover all the wheels, methods and circumstance however.

Anyway, in absence of that, a written warranty from a powder coater would be very convincing, but considering the liability of a wheel failure I wonder if any would. Guess if were my neck on the line I'd rather be safe then sorry and especially on a track I'd hope others would feel the same way.

 

I raced an SVT Cobra with Powder coated wheels for 7 years without any problems...these were Factory Cobra R wheels done in Gloss Black. The SVT was a Hell of a lot Heavier and faster than my mini.

 

Did you hit anything? In that thread I posted I found the info interesting about the heating potentially causing the alloy to become more brittle and that if you do happen to hit anything it can be more extreme as a result of the loss of ductility. Of course, every wheel design, alloy and pc process is different (not to mention the usage/circumstances) so anecdotal accounts all around have limited use - testing would be the only way to really know it seems.