Monday, 25 April 2011

Distinguishing the Coloured Side of Flashed Glass

On smaller pieces of flashed glass you can determine which the flashed or coloured side is by putting it to the light and viewing it through the edge. If the flash is very thin or you cannot determine which the flashed side is, you can alter the angle a little. If you tip the glass down slightly and the light is coming through the clear side, there will be very little variation in what you see.

If you tip it down and you see the colour very distinctly, then the flash is on the upper side.

Also note that on the left side of the glass you can see the effect of the cutter pressure on the glass.  These little hook like marks are evidence of the stress caused by scoring the glass.  This is the kind of mark you will see on glass that has adequate, but not excessive pressure applied during the scoring.

Now back to the subject of the flash.

On larger pieces this is more difficult, and dangerous to you and the glass, as you risk breakage by holding large sheets horizontally. So you can use your grozers to nip a little glass off the edge. If there is no change in colour of the chipped edge, you have taken glass off the clear side. When you chip off the flash, there will be a little bit of clear showing which the coloured side is. Here are two examples.

Once you have determined which the flashed side is, mark it and all off-cuts with a felt tip or wax marker of some kind so that you will not have to perform this action each time.