Painting/Powder coating wheels

[stevan]

Hey mate, saw your other thread and noticed you got the wheels repainted. Lookin good. Outta curiosity, which method did you end up using to paint the wheels?

Hey Andrew, From what i saw the front face was rubbed back and repainted in gloss white.

Word of caution to others in the future, make sure the painter masks and doesn't paint the tappered lug area...

[mrntegra]

wanting to change the colour of my rims(not just the face) by painting or powder coating..

Ive spoken to a few different people and they keep saying powder coating will not hurt the rims. they have all said Paint will chip easily and ill be forvever getting them fixed.

Cant find any actual facts that powder coating is bad.. just alot of people saying its bad.

[EG30]

Getting my rims powder coated atm, not concerned about the heat involved AT ALL.

they are blasting off the bogan black paint off 1st before powder coating them silver for me.

will post some pics once I get them back.

[ChargeR]

wanting to change the colour of my rims(not just the face) by painting or powder coating..

Ive spoken to a few different people and they keep saying powder coating will not hurt the rims. they have all said Paint will chip easily and ill be forvever getting them fixed.

Cant find any actual facts that powder coating is bad.. just alot of people saying its bad.

Here are some facts:

• Many cast and forged aluminium alloy wheels will be heat treated to improve their strength
  
• Any time spent at elevated temperature will continue this heat treatment, potentially over-aging the material to a point where the strength decreases from the new condition or even less than the as-cast/forged condition. The higher the temperature, the shorter the time required for over-aging to occur.
  
• The point above includes heat from general use, or track use, so a hard used aluminium wheel may have a finite lifespan
  
• An intelligent wheel designer will select an alloy such that typical temperatures reached during use will not affect the strength significantly enough to affect safety over a typical wheel lifespan, but not everyone is intelligent. Also has the designer assumed that someone is going to put the wheel in an oven again for a couple of hours?

Getting my rims powder coated atm, not concerned about the heat involved AT ALL.

they are blasting off the bogan black paint off 1st before powder coating them silver for me.

will post some pics once I get them back.

Why are you not worried at all? I'm not saying you should be but for me, the potential for a wheel failure on track is enough for me to be cautious.

[Apu]

I'd question the logic of "don't worry because there will be heatsoak from the brakes".

How much heatsoak is there going to be? Anyone suffer a burn from touching a wheel of a car that just came off the track? Sure it's hot, but it's not like you can light a cigarette on it.

Lighting a cigarette on a brake rotor on the other hand...

Plus, much easier to repair / touch up a wheel with small scrapes. Try powder coating that!

[tinkerbell]

Anyone suffer a burn from touching a wheel of a car that just came off the track?

errr, is this a serious question?

i got burnt simply from the air that came out of the tyre,

my wheels get wayyyy too hot to touch with bare hands after only 5 circuit laps...

[Apu]

No kidding? I've never deflated a tyre directly though - always used the bleeder on the guage.

But like I said, yes, wheels get hot and I should have clarified that I've worn gloves...not fireproof special doohicky gloves, just regular cotton gloves/mechanics gloves.

They're hot, but you can still handle them so I doubt if they're hitting powdercoating temps.

Will be interesting to see if anyone's measured the temps of their wheels?

[tinkerbell]

caught without a bleeder? gotta go direct...

optimal surface temp of tyres can range from 60 to 100'c

this will nearly always be colder than the gas inside of the tyre in a circuit racing situation, as the brake disc heats the wheel (both by radiation and conduction) more than is caused by friction (if you are driving properly)

methinketh you guys underestimate the temperatures experienced by a wheel during circuit racing, particualry the hub mounting face...

particualry since it is not even...

e.g. when the car is stopped after a session, the top half of the wheel will will get heated more than the bottom half, as heat rises!

[tinkerbell]

so since it might seem like i am advocating powder coating (i am not, i am pointing out that the rims get really HOT during circuit racing)

i just had a dig, and it does seem that there is plenty of hearsay on this, but nothing that would convince me that powdercoating will potentially harm every type of wheel,

but the risk is there depending on; what elements are in the alloy; the age of the rim; the original manufacturing process; any existing damge (whether it can be seen or not); and what method of processing (eg existing paint removal) is used by the coater...

so maybe asking the manufacturer is the best option for each personal situation...

[tinkerbell]

http://www.eng-tips.com/viewthread.cfm?qid=151053

and

http://www.m3post.com/forums/showthread.php?t=370990

[Apu]

Thanks for sharing that tinkerbell. Thinking about it more, we do tend to handle a hot wheel by the tyre or spokes. I don't recall ever grabbing it around the hub face...in fact, I don't think I ever have in any situation!

I never thought any of it would hit 100degC...having touched a boiling hot kettle many times, I've not received the same nasty surprise from a wheel.

Hot rotors...well us (former) smokers have had a lot of fun with those.

[tinkerbell]

Thinking about it more, we do tend to handle a hot wheel by the tyre or spokes.

and do you handle it the instant it comes off the track? (maybe you do?)

next time you take a rim off immediatly after a session, grasp the wheel nuts in your bare hand and count to ten...

(don't do this!)

[Apu]

Point taken! I guess when we've taken it off there was always a reason for us to take it off, so no stuffing around and in those moments you don't "feel" as much if you know what I mean!

[mrntegra]

thanks for the info tink! ill go and ask alot more questions about temps etc... then make a decision! But guessing im gonna prob end up painting them