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11-03-2012, 04:46 AM | #1 |
Senior Member
Join Date: May 2010
Location: Bozeman, Montana
Posts: 997
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Powder Coating and Cracked Wheels
A local Model A'er sent 4 wheels to get powder coated and two came back cracked. I sold him two very nice wheels and one came back cracked.
Now it could be that the three wheels had minute cracks that weren't noticed before being sent to the powder coated. However, could it be that the heat used in the curing process stresses the wheels and causes the cracks? Has anyone else had a similar problem? Is it common for a high number of wheels to reveal/develop cracks during the powder coating process? Thanks for your answers in advance. Dean |
11-03-2012, 06:13 AM | #2 |
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Join Date: May 2010
Location: Asheville,NC
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Re: Powder Coating and Cracked Wheels
Dean, the wheels were probably cracked before the powder coating process. When the powder goes on, it is dust and covers everything that is not masked, hiding cracks that may be seen or not with the naked eye. When the powder coat is heated it draws tight and the metal expands so, any gap, no matter how small will show. The only way to insure no cracks would be to have the wheels magna-fluxed before the process.
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11-03-2012, 06:34 AM | #3 |
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Join Date: May 2010
Location: Virginias Shenandoah
Posts: 21
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Re: Powder Coating and Cracked Wheels
I too had one returned to me cracked....after sand blasting.A crack I hadn't seen because of paint and dirt.It hadn't gotten to the powder
coat process.It otherwise looked like a good wheel,so close inspection is warranted. Bud |
11-03-2012, 06:51 AM | #4 |
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Location: Eastern CT
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Re: Powder Coating and Cracked Wheels
Cracked wheels can be repaired. they usually crack in the hub area, where the short spokes attach. That area is a deep draw of thick metal, and is under considerable stress. The only other part I can recall that is similar is the brake drum, and that has a rolled lip which seems to prevent the cracks.
The crack must be ground out in a V shape on BOTH sides, and welded from both sides, to insure complete penetration of weld. Heating the weld area after welding and allowing it to cool slowly will help prevent re cracking. |
11-03-2012, 07:26 AM | #5 |
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Join Date: Jul 2012
Location: California
Posts: 1,696
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Re: Powder Coating and Cracked Wheels
How big of a deal is it if your wheel has a crack in the short spoke area of the hub? It the wheel going to fly apart someday? Could he just drive on it and be safe?
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11-03-2012, 07:47 AM | #6 |
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Location: Liberty, KY
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Re: Powder Coating and Cracked Wheels
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Dale. |
11-03-2012, 07:54 AM | #7 |
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Join Date: May 2010
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Re: Powder Coating and Cracked Wheels
Maybe you are getting back someone else's cracked wheels, not the ones that you gave to powder coater!
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11-03-2012, 08:53 AM | #8 |
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Location: Durango CO
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Re: Powder Coating and Cracked Wheels
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11-03-2012, 11:07 AM | #9 |
Member
Join Date: Aug 2010
Location: Holly, Michigan
Posts: 30
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Re: Powder Coating and Cracked Wheels
Sent eight wheels to powder coater, just to get five good ones, the blast process is very hard, it shot holes in two hubs and one rim. Weak metal is hard to spot when there is paint, rust and other junk. The vender saw the weak area after blasting and stopped. I did get back five very good wheels.
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11-03-2012, 01:36 PM | #10 |
Member
Join Date: Jan 2012
Location: Central Connecticut
Posts: 44
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Powder Coating and Cracked Wheels
I send 10 wheels off to our coater, 5-19" 5-16". they called and said they were ready. When i picked them up i now had 20 19" wheels. I was told that was what i had brought in. After a short heated conversation, i asked if anyone else had brought in "A" wheels. Well guess what, after a quick call to the other customer, he realized that what he had were my 16" wheels. Now my special order powder had to be reordered to recoat my wheels. All that aside, they did do a superb job with the powdercoat.
As far as the cracks go, in my opinion they were already there and masked by previous paint. One thing that i was impressed with was the prep work before powdercoat.They were placed in an oven to soften the previous paint and actually turned the paint to a dust, then they were blasted. I believe that this step helps keeps the blasting down to a minimum. One thing i did notice on one of my 16" wheels that i knew was a little pitted, if the pitting is not removed prior to coat, it's still going to be there after coating. Maybe the pitts could be taken care of with powdercoat primer and sanding but someone is still going to have an awful lot of sanding to do. |
11-03-2012, 04:01 PM | #11 |
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Join Date: May 2010
Location: Mpls, MN
Posts: 27,582
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Re: Powder Coating and Cracked Wheels
I have a cracked wheel in the hub area that I've been running for years. The crack hasn't grown. Some day I'll weld it.
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11-03-2012, 05:09 PM | #12 |
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Join Date: May 2010
Location: Jacksonville, FL
Posts: 292
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Re: Powder Coating and Cracked Wheels
As a suggestion, as I do, take your wheels to the powder coater an let him sandblast them. Pick them up and inspect them for cracks and bent spokes. Straighten the spokes, fill the pits, and if any cracks in the hub, weld the cracks on the inside. On 21 inch wheels, sometimes rust holes show up in the beads or outside edges. Make those repairs. After all that is done, then take them back to the powder coater for color. If they surface rust a little before you get them back, that will be okay because he can gently blast them again them color. You will then have some very nice wheels.
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