Technical Bulletin

Get informed on current glazing news with SCGMA’s quarterly Technical Bulletins written by industry authors.

 

January 2021

“Mitigating the Menace” by Jordan Scott for US Glass Magazine

Addressing occasional risk elements in the commercial glazing industry is important. Anisotropy, a visual distortion or coloring of heat-treated glass when inspected in polarized light, is one example.

Jordan Scott’s article for US Glass Magazine, “Mitigating the Menace,” discusses the progress made in educating firms about anisotropy’s visual impact, ways to minimize its effect, and how to create standards for acceptance.

Anisotropy issues increased when some recent Southern California projects used high-performance coatings on 3/8″ (8mm) glass. It appears that the combination of the expanded glass thickness and the pre-coated, high-performance glass designed to reflect heat creates a challenge in the heat strengthening/tempering process. This effect has led some in the industry to believe it is a significantly negative visual impact, resulting in attempts to reject the glass. There are still no specific conclusions about the visual impact’s causes or severity because of ongoing legal implications.

The purpose of sharing this information is to educate the community and avoid potential product rejection. In some cases, anisotropy concerns were discovered early enough to switch the glazing into a post-coated product, where the glass is heat strengthened/tempered before applying the coating.

We hope this information serves as a useful tool for avoiding anisotropy concerns.

Click here to read “Mitigating the Menace.”