Posted by Gary Dodge on March 19, 2003 at 23:24:13:
In Reply to: inside curvew cracking posted by Angel on March 19, 2003 at 21:25:19:
Hi Bambi,
Another possible contributor to your problem is tight fit.
If you have been obsessed with getting your glass to fit so tightly that not even light can squeak through after it is foiled, STOP.
This leaves no room for local expansion caused by the heat of soldering and will cause glass to crack from the stress created against its' neighbors.
Also, if that is what you have been doing, your work can be fatally weakened as well. You must leave room for solder to flow between the glass pieces to connect the front and back solder beads of your panel. Otherwise the panel is no stronger than the copper foil alone.
GaryD
: Most likely cause is bad cuts. Those lovely deep curved or slightly squared off inside curves are doing what glass is supposed to do..breaking in a straight line where the stress lies. If you're cutting with a saw to get these cuts...stop...it's one thing a saw tricks you into. It lets you do impossible cuts that don't hold up to soldering and handling.
: If you're cutting by hand and doing grozing to break out the inside curve...THAT will sometimes weaken glass with these nasty curves. If you're grinding them out...same thing. Maybe you can add a break/cut line at the deepest part of the curve. This will relieve the stress and probably won't interrupt the pattern flow. Lots of patterns, even the professinal ones have bad cuts in them. Only way to learn to spot these is to get bitten by that tiger a few times while you're learning. Eventually, you're going to pick up a pattern, look at it and say...NO WAY...and make a few adjustments before you start cutting.
: : My glass keeps cracking when I solder glass into my inside cuts. The glass cracks from the inside cut outward. What can I do? I need your help badly. Thanks