Why Does Some Tempered Glass Scratch?

Tempered glass is heat-treated to make it much stronger than ordinary glass. If a panel of glass has been properly tempered, it should resist scratches when scraped with something sharp like a razor blade. However, you will occasionally come across tempered glass that shows scratches.

What Causes Scratches In Tempered Glass?

Most scratches in tempered glass are caused by fabricating debris. It is a manufacturing defect that results in low-quality tempered glass and increases the likelihood of scratching the surface during cleaning.

According to Scientific American, one of the key steps in the manufacturing of tempered glass is the washing of the glass after it has been cut to the desired size or shape and buffed to take off the sharp edges. Unfortunately, not all glass manufacturers do a thorough job of washing the glass before it goes into the tempering furnace.

When dust or debris is still present on the glass when it undergoes the tempering process, they fuse to the surface of the glass. Later on, when the glass is cleaned, the debris can be dislodged and dragged across the surface, leaving visible scratch marks.

Fabricating debris are often the result of poor maintenance of the glass washer used during manufacturing. If the washer is not regularly cleaned, debris builds up, and the glass panels that go through the washer may exit with dirt particles still stuck to the surface.

How To Avoid Scratches On Tempered Glass

A good quality scraper with a razor blade effectively removes adhesive, paint, and other sticky substances from glass windows.

But to ensure that your tempered glass windows or curtain wall stay scratch-free, you need to make sure that your window cleaner does not use a blade on the glass. When the cleaner scrapes the blade across the window, fabrication debris that is fused to the glass could be dislodged and leave scratches on the surface.