Well you don't reach the speeds or the high heat range that you would on race track, but I would always inspect the wheels for any cracks. Which means cleaning the brake dust off after or before every event and really giving the wheel a once over. If you see a crack anywhere on the wheel, it has been my experience that it is pretty serious. The wheel is trash! A wheel falling off a car at 50 or 60 at an autocross is still going to do some serious damage. Then comes the problem of getting home.

Always err on the side of safety !!

 

Just to give an update on this. I spoke with the owner of the wheels from the first post yesterday and they were powder coated. After the incident he had the others stripped down and inspected them and found one more that had a pretty serious crack developing in it.

 

Ha Ha! Called it

 

Glad you saw him as I won't see him until the end of February.

 

We were talking about this in the North Tx forum and DonJ posted this. I think It is some good info so I am posting it here.



"I did some research and came up with the following information:

The Aluminum Association Inc. describes it this way: Heating aluminum alloys above 275°F causes granular rearrangement of the metallurgical structure resulting in a significant change of bulk properties. Essentially meaning, the tensile strength of the metal is dramatically lowered.

Aluminum billet material and/or alloys change crystal structure at about 410°F. The crystalline realignment at 410°F causes the previous ductile aluminum to become brittle; thus the cases of powdercoated wheels shattering under stress.

Peak substrate temperatures for aluminum should be below 300°F--ideally 275°F."

 

That article with it's unsupported reference was linked earlier in the thread .

 

oop's, It's been a while since I read the entire thread.

 

Yes, who cares about science when you can just listen to what Voodoo_S2K tells you instead?

Good thread (except for a momentary diversion into the merits of putting racing stripes on a Mustang): http://www.corner-carvers.com/forums...ead.php?t=5368

 

I was wondering how long it would take you to make that comment.

I offer zero scientific evidence, only observation such as all of the cracking of aluminum engine blocks and calipers.

 

How DO you prepare a wheel before painting if glass blasting is not ok?
Sanding?
Remove the paint with paint stripper?