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RE: Base Metal Preparation

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You have got the fumes area covered.  The next issue is when welding
galvanized surfaces, the zinc must be volatilized.  Basically the zinc is
melted and the volatilized zinc is kept ahead of the molten weld material.
A good welder should not have a problem.  It is an issue of weld procedure.
Reference The Procedure Handbook by Lincoln Electric p 13.2-1.

Harold Sprague
The Neenan Company

-----Original Message-----
From: Brent Koch [mailto:Brent(--nospam--at)]
Sent: Monday, July 26, 1999 6:00 PM
To: SEAOC List Serve
Subject: Base Metal Preparation

I am interested in List opinions regarding the need to grind the zinc
coating off of galvanized metals prior to welding. The following text is
from an e-mail message I sent to the Senior Staff Engineer with AWS.

Dear Mr. Campbell:

My name is Brent Koch. I am a project engineer and a project manager with
Willis Construction Company, an archictural precast and GRFC cladding panel
manufacturer in California.  I have been referred to you by Mark Hildebrand,
our chief engineer, for your opinion regarding the need to grind the zinc
coating off of galvanized metals prior to welding.

As I'm sure you know, galvanized finishes are occasionaly specified for
connections of precast cladding panels. I've run across two opposed schools
of thought [and two schools of enforcement] regarding the necessity to
remove the coating at and around welds.

AWS D1.1 Section 3.2.1 says, "Surfaces to be welded, and surfaces adjacent
to a weld shall be also be free from loose or thick scale, slag, rust,
moisture, grease and other foreign material that would prevent proper
welding or produce objectionable fumes."  This is the only specification
section that I have been able to associate with welding of galvanized metal

Is the galvanizing a foreign material that prevents proper welding and
therefore must be removed? (FYI - The welder will be wearing a respirator so
the fumes produced will not be 'objectionable' according to his employer.)

Thank you in advance for information and insights you can provide on this


Brent Koch, P.E
Willis Construction Company