What’s happened to my wheels?

Abb

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Recently dropped a set of alloys for a refurb, got a call asking me to come in to discuss refurb.

Upon showing me the wheels, which had been stripped and prepped ready for the Powdercoat finish, but the wheels all have an almost mottled effect in them.

Refurb guy says he’s never come across it before!

It has a very good reputation hence I used them.

Any ideas..... hope you can see what I mean.

C654B154-A609-4671-B856-2EE69B5F5CB4.jpeg
 
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Abb

Abb

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Will upload some close up pics once I have figured out how to resize them!
 

clk320x

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Will upload some close up pics once I have figured out how to resize them!

WhatsApp them to me pal and I will upload them if you get stuck! :)
 

clk320x

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Will

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What was the state of the wheels prior to the refurb? As in were they in factory finish or had they been refurbished prior?

I too wonder about the stripping process - it’s almost as if they’re softer than regular alloy (eg magnesium) and have been blasted or etched too strong with something that doesn’t agree with them. Either by the current place or maybe from a previous job.

Doesn’t look good though - hope you work something out :)
 

Alex

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Looks like quite a porous cast. The reason it’s grainy is because the original molten Ali had lots of air bubbles in it. This weakens the structure of the metal but is much cheaper to make than forged wheels, where forgings are formed by a 30,000 tonne press to get rid of air.
 

John N

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Recently dropped a set of alloys for a refurb, got a call asking me to come in to discuss refurb.

Upon showing me the wheels, which had been stripped and prepped ready for the Powdercoat finish, but the wheels all have an almost mottled effect in them.

Refurb guy says he’s never come across it before!

It has a very good reputation hence I used them.

Any ideas..... hope you can see what I mean.

View attachment 87991


Looks like incorrect Blasting Media or over exuberant/high pressure to me! :eek:
 

oldguy57

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Looks like the finish you used to get with old fashioned grit blasting, before the introduction of more sympathetic medias. As Alex said above could be a poor cast on a replica wheel, but I'm more inclined to think the wheels have been cleaned by someone who doesn't know what they are doing. It's possible of course that the refurb company did the damage, and are trying to cover up.
I doubt that powder coating will cover this up- it shows up every defect. Hope they only did one wheel.
 

thebiglad

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This wheel refurb company, are you sure they know what they are doing? I would have thought that for several reasons you would want to take the valves out before acid-dipping the wheels, but they didn't - curious, no ?
 

AltonAnt

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Were they bought from Aliexpress/Alibaba?
I'm not saying everything from there is knock-off rubbish but you have to be careful especially if they are the $50-100 types.
 

st13phil

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Sand cast?
Edge definition (including the raised letter logo) is better than I'd expect from sand casting, however...
Looks like quite a porous cast.
It certainly does. I wouldn't expect to see that from a pressure die casting, but it's possible from a gravity casting if the process control is less than ideal.

Regarding the acid strip or blasting, it's unlikely (though not impossible) that a refurbisher with a good reputation has got it so disastrously wrong - especially if it's all the wheels and not just one or two.

My guess is that the wheels are not what they purport to be, but absent a metallurgical analysis you can't be sure.
 
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Doodle

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Wet paint rather than powdercoat may be a better option here - a couple of coats of hi-build will deal with that.

However, I wonder if these are what Vossen call "Hybrid Forged", so flow formed rather than true pressed forgings.
 

ioweddie

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Replica's????
 

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