Glass rod cutting

[Wantstolearn]

I have been trying to find a solution to the following problem. I have been hired by a glass studio to do some redesign of the glass melting equipment. One of the side projects is either design or the sourcing of some sort of glass cane cutter and also a colour rod cutter. For those not familiar with the terms, let me explain.

Glass cane are rods of glass with colour woven inside. They range in thickness from 1/4" to 3/4" in diameter. The reason they are called cane is because the colour swirled inside the rod resembles a candy cane. The cane is made into long lengths (up to a meter) but only used bits (inches) at a time.

Colour rod (or bar) is one of the ways blown pieces of glass get their colour. The rod is a bar ranging from 1.5" to 2.5" in diameter and only about a foot long of very dense colour. Depending on the size of the piece only small disks of this colour is needed(up to 1" thick). When used the dense colour is surrounded by clear glass and then the piece is blown, the colour spreads thinly on the inside of the piece.

The artists are currently using a pair of tile cutters (shears) to break the cane even though it is very hard on the hands. While the colour rod is chipped into disks with a chisel, hammer and an angled piece of steel. Not very safe. It is very common for shards of glass to splinter off.

And so, I ask if anyone has any knowledge of how these two types of glass could be cut quickly and accurately without the dangers or pain associated with the current way the cutting is done.

 

[Timbo]

If your only cutting an inch thick piece then three methods are at hand. 1- machine: diamond saws are available from places like Heathway or Jensons (UK), and I'm sure many others on the internet - this options is fast, accurate and neat. 2 - Thermal shock: use a glass knife or a metal file to score a mark in the glass, then put a small molten rod (aprx 5 mm in diameter) next to the end of the cut. This will cause a crack to run around the rod to the otherside of the cut, the crack travels deep which means you can easily pull off the small section. 3 - Hot wire: (can be purchased or made in house) rotate the cane on a hot wire for 30 seconds at the area to be removed, take cane away then splash with water, the thermal shock will crack at the heated section, then pull off.

Methods 2 and 3 will only work if the residual strain is minimal or the crack want run straight around the cane.

Method 1 would be prefered becauses its quick, accurate, neat and doesn't matter if the glass has significant strain.
However it's the most expensive of the three.

 

what if the rods are thicker in diameter, like closer to 2 inches??

 

[Timbo]

Use the hot wire if your likely to use rods of 2"+. If the rods are 6" thick it doesn't matter either - you'd be best to use the hot wire. The crack may only be 10th" deep, however it's the disruptin to the surface that makes it easy to break the rod. The crack will easily run deep into the core once you apply a little sideways force.

 

[nbucska]

Rotate rod, head with H2/O2 and touch it with sharp copper disk. <nbucska@pcperipherals.com>