[AT] Automatic parts washer please!

[charliehill]

Steve there was a speaker at one meeting that worked for a huge powder 
coating facility in TN.  They powder coat any and everything right down to 
the cell phone cases and the handles on razors.  Anyway he shared a story 
about some fairly large metal item (something of bbq grill or dishwasher 
size) that they were having small random coating failures on.  They could 
not figure it out until one day someone noticed that some of the workers 
were wearing those silicone rubber bracelets we often see now, usually as a 
symbol for some charity like breast cancer research etc.   They got to 
looking into it and figured out that if one of those bracelets just 
casually brushed against the metal it would put enough "oil" on the surface 
to cause the failure.  They banned folks from wearing the bracelets and the 
problem went away.

Charlie
----- Original Message ----- 
From: "Steve W." <falcon at telenet.net>
To: "Antique tractor email discussion group" <at at lists.antique-tractor.com>
Sent: Sunday, October 04, 2009 12:17 PM
Subject: Re: [AT] Automatic parts washer please!


> charliehill wrote:
>> A few years back I was looking into the powder coating business.  I went 
>> to
>> a couple of seminars and trade conventions.  The secret to a good powder
>> coat job is cleanliness of the parts being coated.  The industry standard
>> for cleaning is hot water with phosphate cleaners.  Basically tri sodium
>> phosphate in a hot water bath.
>>
>> I would think for cleaning grungy parts you'd want to get the bulk of the
>> crud off before putting them in the phosphate bath.  One good thing about
>> phosphate cleaners is that they tend to bind heavy metal contaminants 
>> such
>> as lead.  The waste can then be disposed of without special treatment. 
>> (if
>> you're worried about that).
>
> Powder coat, spent a few years in that business myself. We used
> different cleaning methods depending on the original dirt/grease.
> Most went through a 5 stage cleaning if they were simple oils.
> When odd materials or parts that only had minimal oil came up they got
> vapor treated then coated NOW.
> With powder ANY oil/dirt/contaminate will cause problems.
>
>
> -- 
> Steve W.
>
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