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Hooks corrosion in Powder Coating conveyor

2007

I have an automated Powder coating line, that includes a three steps washer, a drying oven, a powder coating boot and a curing oven. I'm having a problem with corrosion in my steel hooks (to hang the parts) they are getting rust and a lot of the residues are falling over my parts after the powder coating application, as you can imagine this became a major cosmetic problem because the "falling residues" are on the parts during the curing period and can be easily detected in a finished part.

I know we can eliminate this problem changing the hooks to stainless steel, but I'm looking for a cheaper alternative (I have over 1000 hooks in my line), maybe some kind of Chemical treatment to avoid the corrosion. Do you have any recommendation?

Thank you,

Efren Magana
Process Engineer - Carpinteria, California

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If your hooks are corroding, then I wonder what your pretreatment is doing? Assuming you are coating steel (but maybe its aluminium?) then your pretreatment corroding your hooks sounds a problem for the parts being coated too.
If you could get the corrosion stopped (by modifying your pretreatment), then shotblasting the hooks might be an option, or etching in acid, rinse then dry in your drier?
Good luck

Geoff Crowley
Crithwood Ltd.
Westfield, Scotland, UK

2007

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Mr. Magana,
There is quit a bit of information that is being left out here. Can we start with, are the hooks rusting between "new" and "used the first time"? If they are rusting as they run through you normal chemical treatment then Geoff is right on, you need to check your system immediately. But I don't think that this is the case. I will make a guess that they are coming back from your stripper rusty, if that is the case whoever is stripping the paint needs to buy you some new hooks. I'll even bet that you could almost buy new hooks for what you are paying to have them stripped.
Could you give a standard size of your hooks and maybe someone here could give you some ideas on how to cheapen your hook use. I have used paperclips instead of hooks in instances where the part configuration allowed (small and light). And if the owner of the company could have made me do it he would have had me keep and reuse the paperclips, but you got to draw the line somewhere.

Sheldon Taylor
supply chain electronics
Wake Forest, North Carolina
2007