IGMA Visual Quality Working Group Sends Guideline Back to Task Group

Members of the IGMA Technical Services Committee were joined this morning by members of the AAMA Glass Materials Council for a joint meeting.

The Insulating Glass Manufacturers Alliance (IGMA) summer meeting, taking place at the Hyatt Regency in Huntington Beach, Calif., concluded yesterday with the visual quality working group's decision to return its visual quality guidelines back to the task group for revision. The main point of discussion was concern that a single set of visual quality guidelines would not address the unique differences of large commercial insulating glass (IG) units versus residential IG units.

The group discussed the existence of differences between the defect sizes and inspection processes for commercial and residential IG units. There was concern that the current guideline addresses point blemishes, but does not address the inspection process for linear blemishes. While the working group did not find the argument for two separate documents persuasive enough to turn the current guideline into a residential-only document, group members did vote in favor of a motion to revise the document to differentiate and address the differences that exist between the residential and commercial markets.

Another point of discussion for the visual quality working group was the handling and definition of optical interferences that do not constitute visual obstructions. The group agreed to move the definitions for Brewster's Fringes, Newton's Rings and quench marks beneath a general definition for Optical Effects. This, the group agreed, would clarify to readers that these issues are not addressed by the guideline because they are not considered visual obstructions.

Fogging, which is a visual obstruction, was also discussed. There was concern that a brief statement that fogging is not allowed could permit the document's end-users to insist on the replacement of fogged units even after the manufacturer's warranty has expired. The statement was altered to read, "Fogging: not allowed. Consult with manufacturer." The group agreed that since the document is only a guideline it can't be used by an end-user to insist that a unit is replaced, it only indicates that fogging is a visual obstruction; how to deal with fogging is then left to the manufacturer.

The summer meeting continued today with IGMA's technical services committee and education and certification meeting. The IGMA summer meeting concludes Wednesday, June 13.