Glass hole drilling through fused glass jewelry piece requires the use of diamond core drills.
This process is not the same as drilling through metal or wood.
As heat is generated whilst drilling through glass it is necessary to cool the process with water or a similar coolant.
Using a diamond core drill bit will produce the best result. Due to the type of drill bit used it actually grinds through the glass.
These drill bits come in various sizes and have electroplated or brazed diamonds on the drill surface.
For small work a solid core drill can be used. A larger operation will require a diamond core drill bit as per the two hollow drills in the photo.
The following items can be used for drilling:
Drill stands are available for the Dremel and some flex shafts.
Care must be taken when using power equipment to ensure water does not enter the tool or a serious accident may occur.
Always wear safety glasses during the drilling process.
Place your glass piece in a tray with a piece of wood or foam underneath the glass.
Cover the glass with water and commence drilling at a slow speed, gradually increasing the speed to about 1000rpm, lifting the drill up and down every few seconds to ensure that water is between the drill and the glass to keep the drill cool.
Whilst drilling, apply light pressure, watching for any discoloration at the drill tip. Discoloration is an indication that the tip is overheating: this will shorten drill life and may result in broken glass.
Depending on glass thickness you may want to turn the glass over and drill from the opposite side to prevent the glass chipping when the drill comes through.
For a large pieces of glass that cant be submerged, place on a couple of pieces of wood, use modeling clay to make a small dam around the drill hole and then fill the dam with water and commence to drill.
It may be necessary to fire polish the drilled piecei n a warm glass kiln to round the edges.
Watch the fused glass piece to ensure the hole doesn't close completely.