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Discussion Starter #1
Wondering if anyone has had their wheels done like this or had any experience with powder coating in general.
Just had my GW wheels done in a nice silver, the rear wheel is good, but the front one is not at all good. It has some bubbles in - the tech said this is my fault as it's a defect in the wheel - gas leaking out of alloy during heating process. It is also impossible to put the nuts back in to hold the brake discs onto the wheel - the threads on the bolts holes just won't take the bolts despite being masked up for the job. Again apparently my fault! The grooves for the wheel bearing had to be cleared out of debris before I could push the bearing back in - again that was my fault too!!
While the shop decide if I should have a refund, just wondered if any of you guys know about powder coating?
Next time I think I'll have them polished.
 

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There have been a quite a few guys that have had theirs done over on the 1800 site.Don't remember reading about any problems like you have.Sounds like maybe you need another powdercoater.Doesn't really sound like the threaded holes or bearing area was properly taped off.Powder coating is pretty thick and if it got in the threads you might have to run a tap into the holes to clean the coating out.
 

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Wondering if anyone has had their wheels done like this or had any experience with powder coating in general.
Just had my GW wheels done in a nice silver, the rear wheel is good, but the front one is not at all good. It has some bubbles in - the tech said this is my fault as it's a defect in the wheel - gas leaking out of alloy during heating process. It is also impossible to put the nuts back in to hold the brake discs onto the wheel - the threads on the bolts holes just won't take the bolts despite being masked up for the job. Again apparently my fault! The grooves for the wheel bearing had to be cleared out of debris before I could push the bearing back in - again that was my fault too!!
While the shop decide if I should have a refund, just wondered if any of you guys know about powder coating?
Next time I think I'll have them polished.
"gas leaking out of alloy during heating process", That is totally normal with all aluminum and the reason why aluminum parts need to be OUTGASSED which is a hot pre-bake before coating the parts.

Bubbles in powder coat is NOT your fault, and not a defective wheel either.
They should have cleaned the wheel really well themselves then pre-baked it to drive out the gasses. Aluminum is porous and stuff like brake cleaner, wheel cleaners, and other chemicals get absorbed into the pores of the aluminum. When heated the chemicals and such turn to a gas, and they will make bubbles. That is why all aluminum parts need to be Out Gassed first which is basically baking them at a higher temperature than what's needed to cure the Powder Coat.
If say the powder coat needs to be baked at 420F to cure then the part should first be baked at 475-500F to drive out the gasses. Once it's been baked at the higher temps correctly, say 500F, all the gasses should be out of the wheel that will bake out below that temperature so baking at 420F to cure the powder after it's been coated will not create any more gasses or bubbles.

Bolt holes I'm not sure what's wrong. Check for any powder that may have got in them. Carefully use a thread chaser or a correct size tap to clean the threads, but be careful not to cut or damage the threads.
Masked? Did they use plugs to fill the holes or try to tape over them?
If high temp tape, it could have let some powder under if not sealed down really well. Powder gets everywhere when spraying, it's a very fine dust.
Plugs should have sealed the bolt holes and not let in any powder.

If you had to clean out areas of gunk before putting the bearings in, it sounds like a sloppy job to me. What kind of gunk? You mean powder coat over spray or what?

By the way, Aluminum needs to be out gassed as I said, but steel does not as it's not porous. Do they actually do aluminum parts much?
 

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I have a powder coating gun (set up) and was thinking of making my own oven (wife won't let me use hers anymore......) and taking a crack at doing the wheels myself.

I did a couple grape presses a few years ago and they came out really nice. Wasn't hard to do, just can't be in a hurry.
 

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I think chromo said it pretty well. You need a new powder coater. I have tons of fork tubes ,wheels etc powder coated & never have any problems but my coater makes sure he outgasses stuff really well. Its just like painting its all about prep work.
 

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Discussion Starter #6
I really appreciate your replies.​
Chromo: the debris in the recesses for the bearing seems to be dirt & muck from inside the wheels. The guy who pressed the bearings in said that the acid bath the wheels were dipped in prior to powder coating brings all sorts of dirt out from the inside of the wheel ( through the holes in the "spokes") he thinks it's this dirt he had to clean away. He also said I should blast the wheels with an air line through the holes as he can hear lots more debris still inside. I suspect it's a combination of that debris & the acid which have damaged the threads. He's tapped out the threads & put 2 helicoils in the two worst threads so now I can at least get the bike back together.
The wheels were masked with tape & a certain amount of powder coat had bled underneath & that also had to be removed so I could get the brake discs to sit in place.
This has cost so much extra money & time that I'm just gonna see how the front wheel lasts - just can't be hassled to take it anywhere else just yet. Fortunately by the time I get my rotor cover on, I won't be able to see the bubbles at all.
The company still say it's my fault. So annoying to now have to waste more time pursuing them for a refund.
thanks for the assistance, at least I know they have done a bad job.
 

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Did you pay with a credit card? If so contact the card company and see about a charge back for shoddy work if the place don't make it right themselves!

Mistakes happen, but it sounds like they really screwed up your wheel!
Bubbles from not properly out gassing the part.
No excuse for bad bolt holes!
Just baking aluminum to about 400F and letting it cool will not harm threads!

I don't know what powders they used so I say "about" because some powders require lower or higher bake temps than others, some require more or less time at the bake temps also. 380F-420F is about the range for most normal powders.
Some High temp powders like ceramic for use on header pipes or exhaust manifolds require a hotter bake.
 

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I have a powder coating gun (set up) and was thinking of making my own oven (wife won't let me use hers anymore......) and taking a crack at doing the wheels myself.

I did a couple grape presses a few years ago and they came out really nice. Wasn't hard to do, just can't be in a hurry.
I have seen on the net a guy who made his over out of an old refrigerator a tall one, he used a oven heater element in the bottom raised off the floor a bit and with insulation underneath the element bar.

:toast:
 

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Discussion Starter #9
He finally agreed to give me a refund. He offered to re-do the wheel. I said no thanks, don't want him near my wheels again.
Fortunately now things are back on the bike, the flaws aren't visible as the rotar covers hide the bubbles. Thanks again for the help.
 

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They should have cleaned the wheel really well themselves then pre-baked it to drive out the gasses. Aluminum is porous and stuff like brake cleaner, wheel cleaners, and other chemicals get absorbed into the pores of the aluminum. When heated the chemicals and such turn to a gas, and they will make bubbles. That is why all aluminum parts need to be Out Gassed first which is basically baking them at a higher temperature than what's needed to cure the Powder Coat.
If say the powder coat needs to be baked at 420F to cure then the part should first be baked at 475-500F to drive out the gasses. Once it's been baked at the higher temps correctly, say 500F, all the gasses should be out of the wheel that will bake out below that temperature so baking at 420F to cure the powder after it's been coated will not create any more gasses or bubbles.
I agree. This isn't the first time I've heard of corners being cut with powder coating wheels.
 
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