Volume 16, Issue 6 - August/September 2015

fenestration FUNDAMENTALS

Do You Know When to “Let it Go”?
Five Words That Ensure Quality Products, Safe Workplaces
by Mike Burk

I have four granddaughters, all of whom love to sing the words from the song Let it Go at the top of their voice. Since the release of the Disney movie Frozen, you probably know a child who has sung these words over and over and over.

If you are involved with manufacturing, you may have also heard the words “let it go” along with “it’s good enough,” “no one will know,” “the truck is waiting on the dock,” as well as an occasional “it’s not my job, I’m not in the quality department.”

Unfortunately, these words can be heard throughout many manufacturing facilities, door and window plants, and insulating glass departments.

The insulating glass industry offers exceptional warranties, often from 20 years to a lifetime. When our product fails, the failure is not subtle or hidden; the defect is there every time the customer attempts to look out the window. The failure can sometimes be catastrophic.

Poor glass edge quality can cause an insulating unit to suddenly break or shatter. Insufficient seals can cause a unit to fog, making it impossible to see through the glass. Crooked or scratched muntins can annoy a customer with each glance outside. There is no room for a “let it go” attitude when producing insulating glass units.

A “let it go” attitude does more than produce one bad unit. Since no action is taken to address the source of a quality issue, many more units will follow with the same defect. Steps must be taken to make sure that everyone is aware of the requirements of a good insulating unit. Everyone should know what actions to take when a defect is discovered.

Most are familiar with the 5S methodology for workplace organization. Seiton, Seiri, Seison, Seisou and Seiketsu (Systematic arrangement, Sort, Shine, Standardize and Sustain) can bring improvement to any product or process. Now consider a simple methodology to help assure the quality of insulating glass units. This method does not require any sophisticated tooling, and it can be implemented by anyone from the front office to the shipping dock. It is a 5S system for insulating glass quality which consists of Sealed, Size, Sequence, See and Standards.


An insulating glass unit must be completely sealed. Any voids in the wet out or fourth corner may cause the unit to fail. Voids will allow any gas fill to quickly exit the unit and be replaced by moisturized air. Once the desiccant drying capacity is reached, the unit will begin to fail. As accumulated condensation on the inside evaporates, the moisture will leave behind the white film that tells the world the unit has failed. Be sure to inspect the moisture barrier around the entire perimeter on both sides of the unit. If there are any voids caused by spacer handling, inconsistent or misapplied sealant, insufficient heating and compression or a poor fourth-corner patch, don’t let it go.


The IG unit must be the correct size. This includes the height and width of the glass, spacer and glass alignment, and the overall thickness of the unit. The next stop for the IG unit is the glazing department. If the glass is too big, out of square or if the overall unit thickness is too large, the unit may break while being glazed. If an oversized unit makes it past the glazing department, the added stress may cause the unit to break during normal operation and/or daily thermal cycles. If the unit is not the correct size, don’t let it go.


The improved performance of insulating glass manufactured today is often dependent on multiple layers of glass, suspended films or sophisticated coatings. It is critical that the unit be assembled in the correct sequence. If the unit is not built in the correct order with the specified glass type, the unit will not perform as desired. If the outside surface is labeled properly, the unit may be glazed incorrectly. This can defeat the advantages of the coatings or cause the unit to fail prematurely. Understand how insulating glass surfaces are numbered (Surface 1 to the sun), and take the necessary steps to be sure that the surfaces are properly orientated and labeled. Some low-E coatings are hard to detect, making it difficult to confirm the correct sequence. If the components are not assembled in order, don’t let it go.


Our customers purchase doors and windows with insulating glass units not only to reduce energy consumption but also to see the outside. Fingerprints, scratches and dirt on the inside of the unit will obstruct that view. Misaligned muntins suddenly become much more noticeable when the unit is mulled next to another unit. Scratched muntins and burrs send a message of poor quality. Be sure the muntins are aligned, and free of scratches and burrs. If the insulating glass unit is not free of scratches, smudges or dirt, don’t let it go.


Our industry is able to offer extended warranties and maintain an excellent reputation for high quality due our compliance and testing to industry standards. Manufacturers and associations have developed their processes and individual specifications in order to meet or exceed these standards.

Become familiar with your companies’ quality and process requirements. If the insulating unit you are viewing does not meet or exceed these specifications, inform your quality department, but do not let it go.

When to Let It Go

Finally, there is one very important time when you must remember to let it go. When handling glass lites or insulating units, keep in mind that glass is very dense and may be much, much heavier than you imagined.

Also remember that gravity is always trying to make it fall. If the glass lite you are handling starts to slip, step out the way and let it go. If you witness a glass lite or an insulating unit about to fall from a conveyer or glass rack, don’t try to catch it—let it go. Get out of the way and let it fall. Never try to stop it or catch it. The glass can be recut and the unit can be remade. You and your safety are too important not to let it go.

Mike Burk
is technical manager for Fenestration Fundamentals, a company specializing in customized workplace training for the fenestration industry. He can be reached at mike@ fenestrationfundamentals.com.

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