Arc Welding 101: Finding clues in the AWS D1.1 Commentary

Q:The company that I work for makes a single-pass circumferential weld on which there is a minor tendency for an open pore in the weld crater at the tie-in. Our engineering department deems this weld discontinuity as a cosmetic issue only and thereby has authorized the use of a sealant.

In the 2010 version of the AWS D1.1 code, the Commentary paragraph C-5.28 states that if all inspections of weld and base metal have been completed and accepted prior to application, a nonmetallic filler or mastic may be used for cosmetic reasons.

Is our application consistent with the intent of this paragraph in the commentary, or is it referring to something different?

Anonymous

A: I can’t tell you how good it makes me feel that you would explore the Commentary to learn more about the code’s intent. That’s what the Commentaries are there for.

Your interpretation on the use of fillers in this situation is correct. If your engineers have deemed this discontinuity to be acceptable, then the use of fillers is a good way to enhance the look of this surface. And, yes, you are still within the guidelines of AWS D1.1.

I implemented this same repair recently for a local manufacturer. Their old way of doing business was to take a GMAW gun to these pinholes and “zap” weld into them. This version of the repair turned a perfectly acceptable discontinuity into an arc strike—a big no-no in the wonderful world of welding.

There is risk with this practice. The last thing you want to do is to use that same filler on unacceptable defects. Using fillers to mask unacceptable undercut, overlap, or porosity (pinholes) would be disastrous. So be sure to monitor this practice closely.

I’m glad you opted for the Bondo over the arc strike, and I’m glad you turned to the Commentary to understand the code’s intent.