how to tell if glass is tempered.

[zygote2k]

he Appearance of Quench Marks in Heat Strengthened and Tempered Glass

 

When viewed under particular lighting conditions, especially when viewed at a grazing angle, faint shadowy spots and lines caused by the air quench process can often be seen in heat treated glass. These spots can be seen in transmission and in reflection, and at most viewing angles, other than directly facing the glass. They become very visible when polarizing sunglasses are worn. They are easily seen on a sunny day when the light comes from a dry blue sky or is reflected from clouds. They are less visible on a grey, cloudy day. These spots and lines are a normal function of properly tempered glass and are mentioned in section 7.5 of ASTM C 1048 standard for heat-treated glass. They are more visible in thicker, clear, heat treated, glass; when a lightly reflective coating is used; or when both lights of glass in an insulating glass (IG) unit are heat treated. They are often seen in the single glazed, monolithic, sloping tempered back windows of cars. In Asia they are often very obvious in some small truck tempered flat windshields.

[Coral Hind]

Check this tread out.

http://www.salt-city.org/showthread.php?t=9542

[lanman]

Excellent! Don't have to wait for a sunny day!

 

bob

[davelin315]

So if it's not tempered you'll see a pair of pants?