Brian:
		Isn't it possible to trap all or most of the solids in a
filter  or series of filters, before they get attached to the surfaces
and avoid the scaling on the surfaces? Or would it be prohibitive
expensive?
	Regards,
	Ramon
	 

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Brian Ellis
Sent: Wednesday, January 10, 2007 3:57 AM
To: [log in to unmask]
Subject: Re: [TN] Descaling of Water Wash Systems

There are two problems here. One is lime deposits and that is easy to
handle with any weak acid (do NOT use HCl in stainless steel, though). I
recommend dilute formic acid, but it requires careful handling (see
MSDS). The other is deposits from the solder paste/flux/wash chemistry
and they can be very difficult to remove, depending what chemicals are
involved. Possibly the worst product is hydrolysed rosin which forms a
white crud that sticks to anything and is insoluble in most ordinary
products likely to be found in an electronics workshop. I think the only
thing to do with it is to scrub it with an IPA saturated cloth, with
plenty of elbow grease and patience. Do NOT use abrasives, such as
Scotchbrite pads or pumice, as they will roughen the surface of the
stainless steel, providing a nice key for thicker future deposits.

Maybe we need Teflon/Silverstone coated machines!!!

Brian

Richard Kraszewski wrote:
> To ~continue along this forum's recent cleaning track...
> 
> What are you using for de-scaling water wash systems?
> 
> Any recommendations would be appreciated. 
> 
> Rich K / GTS
>   
> 
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