I've seen some comments here and there that powder coating (with uneven heat, which can happen sometimes) can weaken lightweight aluminum wheels. Any truth to that statement? Could anyone elaborate on how improper heating weakens the structure?

I guess the other alternative would be anodizing then, has anyone on here done this? Any idea of price? Powder Coating also seems nice since it's only around $40-50/wheel or slightly more for custom colors. It also appears to offer more finishing options - metallic colors, etc.

I love the wheels, but silver on silver isn't for me ; )

Thanks a lot!

-st

A bit off-topic, if you are simply unhappy with the color, you could sell your current wheels (lots of people like the STI BBS wheels) and use the proceeds to buy wheels with the color that you like.

I would imagine that powder-coating BBS wheels would decrease their value if you ever sell them later since they are so desireable as-is.

the heat used in th epowder coating process will anneal the metal of the wheel thus, making it much softer and prone to bending

There seem to be some people who think the heating/annealing problem is overstated. They argue that if you feel the brake heat after a day at the track, it feels about as warm as a power-coating oven. Also, some people say that it is UNEVEN heating in the oven that causes problems and that most good powercoating places do not have such problems.

However, I tend to agree with Luke here. On a car, the wheel is in open air and the heat from the brakes is blends with cool atmospheric air. If the car is in motion, the wheel is being constantly cooled. On the other hand, heat from an oven subjects the entire wheel to heat for an elevated time.

I suggest you sell your wheels in the classifieds here - STI BBS wheels are highly desireable - and buy yourself some new rims in the color that you like. Heck, you can take this opportunity to upgrade to 18" wheels.

I have powder coated several sets of wheels with no issues. The time in the over is minimal and the heat is not that intense. The wheels have to be completely stripped of any paint or coatings. Another very safe option is to paint them. They are painted from the factory so just have a good quality urethane paint shot on them Any color you like.

Yeah, my main concern is that the stock BBS are only going for about $1600 with tires on Ebay. I can't buy high quality forged aluminum wheels and rubber for that price.

-st

Thanks for the info Luke.

-st

No 18s for me thanks - I live in Pittsburgh and I like the look of 17s on the STi. I already have to dodge tons of potholes on the way to work : )

-st

From my understanding, wheel collision is about the best refinisher and I've seen their wheels chip quite badly. They also charge quite a bit for refinishing - over $100 a wheel and then there is shipping also.

-st

What temp is a powder coating oven?

Likely the oven will over-age the aluminium, the BBS web site doesnt say but I'd gues that they heat treat the wheels to a T5 or T6 heat treatment to provide the highest strength. once the aluminium is held at temperatures high enough (which temp depends on the alloy, some are held below 0degF until put into service they get stronger at room temp) it looses both yeild and ultimate strength.



nick

PS I'll test your BBS wheels for ya, I'll need all four for a few months (next summer) w/tires please.

Being that the wheels are forged....heat would have very little affect on the strength. Much like using forged rods in a motor.
Powder coating is really not hot enough to have any negative affects.
BTW: most motorcycle wheels are powdercoated no problems at all. Chrome will weaken a wheel a lot more.

Explanation of forging:
http://www.tech.clayton.edu/eddins/Forging.htm

Umm really....

Forged aloys are sensitive to heat, without knowing the chemistry (say 7xxx or whatever A356 etc...) of the alloy then it is impossible to say wether a Powder coating oven is hot enough to cause a problem.

Again.... How hot for how long would a wheel be in the oven?

nick

Thanks for all the replies people.

-st

we have had many people with forged wheels that are heat treated from SSR, OZ, BBS, etc. powder coat their wheels only to find them extremely soft afterwards ...... many have even had them bend when installing tires on them ...... just watch Jesse James from Monster Garage make a fuel tank for a chopper and you will see how easy it is to anneal metal .....

Yeah, I've decided to try to get them painted. Now I just need to find a good place. My friend had Wheel Collision in Bath, PA do his Volvo wheels, but he hasn't been real happy with the finish - chips, etc. Any recommendations?

-st

Find a local body shop to do it. If you have a connection the painter may do it as a side job. Body shops doo wheels all the time. You don't need a special wheel refinisher. If there is no damage they just need to be cleaned and painted. I recomend using a urethane paint for durability. Enamel won't last long. Urethane clear top coat for extra protection.

Thanks for the tip - I actually have a really good PPG shop and a very good Standox shop near me. I'll see if they can help out. Maybe they will unmount/remount the tires for free too : )

-st

For the record, we went to the Rally-X today and one of my friends has BBS STI rims powdercoated black. Coming around a turn his front passenger rim got bent and scraped his brake caliper pretty bad. First hand evidence that the process DOES affect these rims. For the record there were probably 15-20 STIs there and I don't think anyone else had problems. Even my WRX stock 16s held up great.

Hey Nick,

Powdercoating oven temps are typically 400F and parts are in the oven for approximately 20 minutes.

My first hand experience (two sets of powdercoated wheels) is that Detroit area roads are hazardous to any wheel and that the powdercoating has not affected them.

Todd

Proof of my post yesterday ... pics in this thread on page 4... check em out...

http://forums.nasioc.com/forums/show...64#post9321464

I know actual cases of STi wheels getting bent after chroming or powdercoating and then taking turns

Todd- Considering that the T6 heat treatment (one of the strongest) is performed around 300-350F I definately wouldnt powder coat any forged wheel. There is no way to know what alloy BBS uses and there is no way to know what heattreatment they use. I just dont see it being worth the complete destruction of really nice forged wheels cause they are the wrong color....

Is it ok to powder coat non forged aluminum wheels? Like WRX wheels?

-Jason

Ahhh.. Id been waiting for this one... I cant see any reason why Powdercoating would hurt any cast wheel... Unless the wheel is cast from A356 or other heat treatable alloy...

Well considering that no-one knows what alloy any wheel is made from you may just have to live with this SWAG:

Powdercoating of alloy wheels can have unknown effects on the strength. The likelyhood of damaging the wheels increases with the value of the wheel. If the alloy is heat treated using any of the age hardening processes there could be a significant reduction in the strength of the wheel. It is however unlikely that the less expensive OEM and other wheels are age hardened.

So YMMV and powdercoat at your own risk.

Ive had mine powder coated for about 16K and not one ploblem. They are gloss black and it helps with brake dust and makes the car look awsome. Here is a link to an old for sale post with pics
http://forums.nasioc.com/forums/show...20#post8177220