Monday, June 11, 2012

Using "Bond-o" Fillers on Acceptable Discontinuities

The company that I work for makes a single pass circumferential weld , on which at the tie-in on the weld completion, there is a minor tendency for a open pore in the weld crater.
Investigation into this reveals terms such as a pinhole, blowhole, fisheye, or crater pipe are used to describe this condition.
Historically, we have filled the crater and pore with weld metal and sent the product on for a paint application.  More recently , the practice of filling the pore area with a non-metallic high temperature sealant  has occurred.
Our Engineering department deems this weld discontinuity as a cosmetic issue only, and thereby has authorized the usage of the sealant.
We use the principles of the AWS D1.1 code. In the 2010 version , 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 the above application consistent with the intent of this paragraph in the commentary, or is it referring to something different?

Hi (Name removed as promised),
I can’t tell you how good it makes me feel that you would explore the Commentary to learn more about the codes intent.  That’s what the Commentaries all about.
Your interpretation is correct on the use of fillers in this situation.  If your Engineers have deemed this discontinuity to be considered acceptable, then the use of fillers is a good way enhance the look of this surface, and Yes, you are still within the guidelines of AWS-D1.1
I recently implemented this same repair at a local manufacturer.  Their “old way” of doing business was to take a Mig gun to these pinholes and “Zap” weld into them.  Their repair was taking a perfectly acceptable discontinuity and turning it into an Arc Strike.  A big no-no in the wonderful world of welding.
I’m glad you opted for the “Bond-O” over the “Arc Strike”.  Good call and good luck.

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