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Read Gary Mauer's GPD '15 paper
urging the glass industry
 to plan for tempered glass quality.


"Scrapers & Fabricating Debris - 2017"
 Window Cleaning Network Bulletin

This is a Window Cleaning Network resource for the glass, construction and window cleaning industries, and owners of new homes and buildings.

This website focuses on one issue - excessive abrasive fabricating debris defects on some uncoated tempered glass surfaces. The mission here is to provide credible information, and to increase demand for quality tempered glass surfaces.

Builders and homeowners have taken the hit for millions of dollars worth of damage to tempered glass. They may have blamed window cleaning practices for this damage, often without realizing that fabricating debris may have been the root cause, or without understanding how an uncoated tempered glass surface might have so much fabricating debris that it will scratch so easily.

The issue here is why some uncoated tempered glass - but not all - may be so laden with abrasive fabricating debris that it will scratch when you clean it with a standard window cleaning scraper. Fabricating debris is an inherent problem with tempered glass, but clearly some temperers do a good job of minimizing it, while others do not.

We've been urging fabricators to test their own glass for this problem since 2005.

Builders, architects and remodelers who understand that fabricators are able to minimize fabricating debris issues can specify tempered glass surfaces without excessive fabricating debris - surfaces that can be cleaned efficiently with standard methods, not only after construction, but throughout the life of the home or building.

A "perfect" surface is not necessary. What is needed is a surface that does not have so much fabricating debris that it will scratch when you clean it with a window cleaning scraper.

Scrapers do not scratch glass -
Fabricating Debris does!

Scratches in Temperd Glass Caused by Glass Fines  

Clearly, these (magnified) tempered glass scratches did not occur until a scraper encountered a surface defect.
Look closely and you can see that some of these surface defects have caused more than one scratch.
Photo courtesy Dan Fields, Fields Construction Services, Inc.)



Tempered glass scratches GROW!

It takes about 16 hours for tempered glass scratches to grow - up to ten times wider than they first appear.
They will grow wider - not longer.)
One study said, "Macroscopically visible chipping of glass fragments at the scratch face widens scratch tracks from typically 20-30 [microns] to 200-300 [microns]."

These photos appeared on the cover of the June/July 2013 issue of American Window Cleaner Magazine

Some of Gary Mauer's first photos of this effect - before and after a tempered glass scratch grew.
While observing the this segment with a shop microscope about 45 minutes after photographing the new scratch, he observed the distinct, sudden scratch growth shown in the after image.
It made a tiny “poink” sound.

Too many professional window cleaners mistakenly believe they can avoid fabricating debris scratches on tempered glass by following GANA's advice to stop and check a small area or one small window for scratches.
They have to be warned about tempered glass scratch growth.