Powder coating
#6
General Pimpin'
iTrader: (7)
I'd have them painted if it was me but saying that...
I'm tired of people talking about metal fatigue when they don't know what they're talking about. If you take your wheels to a REPUTABLE professional the chances of crack failure do to metal fatigue wouldn't increase due to the powdercoat process... not even the cleaning process unless the shop is stupid and uses a cleaner not compatible with aluminum.
The PC process is under 400 F and WELL under an hour.
Go run your car on the track and take a thermo scan of your wheel temp.
356-T6: aging at 305 to 315 °F for 2 to 5 hours
Yield stress = 185 MPa
Ultimate stress = 262 MPa
Fracture strain = 0.05
356-T7: aging at 435 to 445 °F for 7 to 9 hours
Yield stress = 165 MPa
Ultimate stress = 220 MPa
Fracture strain = 0.06
I'm tired of people talking about metal fatigue when they don't know what they're talking about. If you take your wheels to a REPUTABLE professional the chances of crack failure do to metal fatigue wouldn't increase due to the powdercoat process... not even the cleaning process unless the shop is stupid and uses a cleaner not compatible with aluminum.
The PC process is under 400 F and WELL under an hour.
Go run your car on the track and take a thermo scan of your wheel temp.
356-T6: aging at 305 to 315 °F for 2 to 5 hours
Yield stress = 185 MPa
Ultimate stress = 262 MPa
Fracture strain = 0.05
356-T7: aging at 435 to 445 °F for 7 to 9 hours
Yield stress = 165 MPa
Ultimate stress = 220 MPa
Fracture strain = 0.06
#7
Registered User
iTrader: (1)
Join Date: Jun 2004
Location: Sonoma, CA
Posts: 548
Car Info: 02 WRB WRX
That looks familiar.
http://www.eng-tips.com/viewthread.c...151053&page=10
I would definitely have them painted. I've seen first hand what happens to powdercoated wheels at the track. Not pretty and very expensive. I know plenty of "reputable" shops that won't powder coat wheels because of the liability.
Bill
http://www.eng-tips.com/viewthread.c...151053&page=10
I would definitely have them painted. I've seen first hand what happens to powdercoated wheels at the track. Not pretty and very expensive. I know plenty of "reputable" shops that won't powder coat wheels because of the liability.
Bill
#9
General Pimpin'
iTrader: (7)
That looks familiar.
http://www.eng-tips.com/viewthread.c...151053&page=10
I would definitely have them painted. I've seen first hand what happens to powdercoated wheels at the track. Not pretty and very expensive. I know plenty of "reputable" shops that won't powder coat wheels because of the liability.
Bill
http://www.eng-tips.com/viewthread.c...151053&page=10
I would definitely have them painted. I've seen first hand what happens to powdercoated wheels at the track. Not pretty and very expensive. I know plenty of "reputable" shops that won't powder coat wheels because of the liability.
Bill
I know plenty of reputable shops that do powdercoating... so I don't know what that has to do with anything.
I've seen painted wheels explode at the track so I'm not sure how that disproves the science. A 10 to 20 minute bake in 400 degrees should have less than 1 percent effect on the integrity of a well built wheel.
But still... I also recommend painting because its not worth it ON THE TRACK. If this for show use and street only I don't think it matters. But that's just me. This is a topic that comes up A LOT on mountain bike forums. That's actually where I got the information for the cleaner effect on aluminum as many of the frames the kids want to PC are aluminum.
this is one of those topics that has strong support on both sides and on my car personally I er to the side of caution... and in this case that's paint.
#10
Registered User
iTrader: (1)
Join Date: Jun 2004
Location: Sonoma, CA
Posts: 548
Car Info: 02 WRB WRX
It really is a good site. There is a lot of technical information on that site that's helped with a few builds in the past.
For street use only, I could live with it. But, if you put some sticky tires on, you playing with fire. Most coaters that I take things to, leave items in the oven for 30 minutes max. These are tables and chairs and such. 10-30 minutes is more than enough to age the metal. If you read the second post in the link I posted, one of the members states that common casting alloys can age in as little as 10 minutes at 325 degrees.
10-20 minutes at 400 degrees will age your wheels. To what extent? You would have to do some testing to find out. But, rest assured, it will age them. BTW, where did you get the "less than 1%" figure? I'm not trying to argue, mind you, I just want to get the facts out there. Based on what I've read in the past, 400 degrees "should" have a greater effect on the aging than just 1% if held at that temp for at least 20 minutes.
I have first hand experience with one set of wheels that broke on the track and I have been there to see 2 more sets break as well. The only thing they had in common was being recently powdercoated and running on Khumos at the time. These were all good quality OEM and aftermarket wheels. One set was an original set of Ford Cobra R wheels in 1995.
Bottom line is, do what you want but, do your research first. And I'll second the fact that it's better to er on the side of caution when dealing with your life and the lives of others.
Bill
For street use only, I could live with it. But, if you put some sticky tires on, you playing with fire. Most coaters that I take things to, leave items in the oven for 30 minutes max. These are tables and chairs and such. 10-30 minutes is more than enough to age the metal. If you read the second post in the link I posted, one of the members states that common casting alloys can age in as little as 10 minutes at 325 degrees.
10-20 minutes at 400 degrees will age your wheels. To what extent? You would have to do some testing to find out. But, rest assured, it will age them. BTW, where did you get the "less than 1%" figure? I'm not trying to argue, mind you, I just want to get the facts out there. Based on what I've read in the past, 400 degrees "should" have a greater effect on the aging than just 1% if held at that temp for at least 20 minutes.
I have first hand experience with one set of wheels that broke on the track and I have been there to see 2 more sets break as well. The only thing they had in common was being recently powdercoated and running on Khumos at the time. These were all good quality OEM and aftermarket wheels. One set was an original set of Ford Cobra R wheels in 1995.
Bottom line is, do what you want but, do your research first. And I'll second the fact that it's better to er on the side of caution when dealing with your life and the lives of others.
Bill
#11
General Pimpin'
iTrader: (7)
blame it on the khumos...haaa.
I'll try and find the stuff I read on fatigue rates.
I'm going to sign up for that site. I've been getting interested in casting lately and motor building. I have my 53' caddy motor almost back together. I just have to put together a custom PCV set up.
I'll try and find the stuff I read on fatigue rates.
I'm going to sign up for that site. I've been getting interested in casting lately and motor building. I have my 53' caddy motor almost back together. I just have to put together a custom PCV set up.
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305f, businesses, ca, coat, coated, coating, county, motorcycle, powder, powdercoating, rim, rims, sonoma, valley, wheels