Glass Production
1) Material
1.1) Glass Rod:
The main ingredient of glass are sand (silica), soda, Lime. Over the centuries these ingredients have changed very little. There are many different types of glass available for use, however, the glass used by our artistic glass blower is borosilicate glass.
Physical Data
| COE |
: |
32 |
| Strain point |
: |
510 °C |
| Annealing temperature |
: |
560 °C |
| Softening temperature |
: |
821°C |
| Working point |
: |
1252 °C |
| Refractive index |
: |
1.474 |
| Density |
: |
2.23 g/cm3 |
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2) Glass Working Tools
- - Oxygen/LPG burner
- - Flaring tools: carbon, steel, brass
- - Special tools to make various shapes
- - Mask
3) The Flame Working Process/Lampworking Process
The glass rod is heated in the flame of the Oxygen/LPG burner, to the working point, when it is shaped using any number of different techniques such as, applying glass, twisting, folding, blowing, squashing, cutting etc. When the final shape is completed, the item must be annealed, to remove the stress built up in the glass during and after working
3.1) Stress in Glass
Internal stresses develop when two or more areas in a mass of glass are heated or cooled unequally. The surface of a molten mass cools faster than the interior, and hardens first. The interior, which is now encased by a rigid envelope, continues to cool and shrink as it stiffens. Stress develops when the shrinking interior attemps to pull away from the unyeilding envelope. This situation occurs when working rods of glass in the flame, where the region that has been completed is cooling down, and the current working area is being heated up, ready for shaping.
3.2) Removal of stress
Internal stresses are relieved in glass by slowly heating to the annealing point, the temperature at which the molecular arrangement is so altered within a reasonable period of time that the internal stresses disappear. After the internal stresses have been removed, the temperature is gradually lowered - so slowly that all regions of the mass are at practically uniform temperature during the cooling. The mass shrinks uniformly and no strains develop. The treated piece is said to be "annealed"
4) Durability
All figurines are carefully kiln annealed to ensure the strength of the glass. Annealling at a temperature close to 1000 degrees allows the glass molecules in the figurines to alleviate any stress that has formed during the lampworking process. A slow descent to room temperature ensures that the glass is strong enough
5) Care and Cleaning
Lampworked glass can be cleaned with water to restore it's wonderful shine. However, you should be very careful as the piece could become very slippery and fall out of your hands.
6) Displaying
No matter what type of glass it is, the more direct light each piece gets the more it will shine and show its true colors. If your display cabinet has recessed light at the top, middle and bottom, the following is not as important in displaying as for those of us who only have lights shing down from the top only. Never place solid stands (wooden or plastic) on the top shelf. This only blocks the light for the pieces displayed on the middle and bottom shelves. Try to arrange the larger pieces on the bottom or middle shelves. This will help the light shine more freely thru the glass shelves.
More importantly, this will minimize the weight on the top shelf thus making it less likely for the top shelf to break causing severe damage to the entire collection. You hear horror stories from people who had the top shelf break because of the weight or plastic tabs that support the shelf getting brittle from the heat of the lights and/or the age of the supports. If you have those plastic tabs supporting your shelves, change them, you can buy metal ones in a variety of colors from a home improvement store.
