Posted by Gary Dodge on October 16, 2002 at 02:31:15:
In Reply to: Glass breaking wrong? posted by Kim on October 15, 2002 at 20:39:33:
Hi Kim,
The most likely culprit in your predicament is gravity.
When you work small gravity is not a factor in glass breaking because the pieces themselves are not that heavy. As an example, imagine taking a 6" by 6" piece of glass and scoring it down the middle. Now hold onto one end of the scored glass and let the piece stick straight out from your hand. Nothing happens.
Now imagine taking that 2' by 4' piece and scoring right across it at the 2 foot mark. Now just slide the glass gradually off the edge of the table. Before the score line even reaches the edge of the table, the pull of gravity on the large piece that is hanging over the table edge causes the sheet to bend and the score line to open up. The glass breaks and crashes to the floor.
To take this a step further, imagine taking the same 2*4 foot sheet of glass and grasping it firmly at one end and trying to hold it sticking straight out. No score line at all, just hold the sheet flat supporting it only at one end. Chances are the sheet will just break under its' own weight.
When you work small you must intentionally open the score line to make the glass break. In large sheets you need to handle the glass with extreme care to avoid the weight of the sheet itself from exerting unwanted and uncontrolled forces on the score line.
Watch how you handle the scored glass and if you are trying to cut intricate shapes, make less radical shapes first, then trim and sculpt the shape to perfection gradually. The Morton Safety Break system can be a big help in controlling the score line in large work as it allows you to keep the sheet pretty much on the table and just slide the score line atop the button to apply breaking force above it with the pressure block.
GaryD
: I'm trying to make a large piece. Having trouble with the glass not breaking on scored lines. I'm working with a piece of glass that is 2 ft x 4ft. Need all the glass to make the piece. So I can't cut into small handling pieces. The glass is Spectrum glass clear blue with white swirls. I have never had this problem before. But this is my first large piece.