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Re: Galvanizing Operations



Ric,

There is a good discussion of hot-dip galvanizing in Volume 5 (Surface
Engineering) of the ASM Handbook series.  They refer to adding lead for good
adhesion out of high-temperature galvanizing operations, but it looks like
added lead may not be as necessary in low-temp operations.  Rather, the lead
is present as an impurity, as part of the 1-3% non-zinc material allowed
under ASTM standards.

I also looked at "Galvanizing (Hot-Dip)" by Heinz Bablik, and this old but
trusty text states that lead is an unavoidable constituent (refining of zinc
is essentially the removaL of lead) and furthermore it becomes more
concentrated if a galvanizer uses re-melted zinc, and over time as the bath
is used.

Is lead-free galvanizing possible?  My guess is that it may be already under
some conditions, and could be in others, but has not been a research
priority.

 
--Terry Foecke
Managing Partner
Materials Productivity LLC
6701 Penn Avenue South, Suite 200
Richfield, MN  55423
(p) 612-243-3605
(f) 612-243-3608 


> From: "Illig, Richard" <rillig@state.pa.us>
> Reply-To: "Illig, Richard" <rillig@state.pa.us>
> Date: Fri, 7 Dec 2001 14:44:10 -0500
> To: "'P2TECH'" <p2tech@great-lakes.net>
> Subject: Galvanizing Operations
> 
> All,
> 
> Is there such a thing as lead-free galvanizing?  Galvanizing Association
> websites (3 I found) do not seem to discuss lead/environmental issues.
> 
> Could lead-free zinc, If there is such a thing, be used or is lead an
> integral part of the process with trace amounts always present in the zinc
> (or leached into the zinc bath from steel/iron/metal parts being coated)?
> 
> The archives contain several comments mentioning lead/galvanizing - mainly
> in terms of lead being added - to achieve a desired surface coating.
> Nothing related to lead reduction other than in post-galvanizing processes
> (parts washing/machining).
> 
> As always, any help or direction would be appreciated.  Happy Holidays, Ric
> 
> 
> 
>