GLASKOLBEN cylinders are pre-blown clear glass cylinders with blow pipe ends, used for blowing glass balls. Glaskolben cylinders are used throughout Europe for making Christmas tree ornaments. "Glaskolben" is a German word that translates to "glass bulb."
WATCHAVIDEOONBLOWINGGLASKOLBENORNAMENTS.
SUPPLIES/EQUIPMENT:
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Torch head for Mapp Gas use
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Gas/oxygen torch
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Glaskolben™ cylinder
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90 COE frits and powders for decoration
- Ornament cap and loop set (available in gold or silver)
COMPATIBILITY
Glaskolben is compatible with Uroboros and Bullseye 90 COE glass frit and powders. Do not use any other COE as it may cause stress or fracture.
HOWTOBLOWANORNAMENT
1. Light the torch and adjust the flame - a broader flame is better. Select a Sealed End Cylinder Glaskolben™ and introduce it into the back of the flame away from the torch. Rotate it as it is brought into the hotter area of the flame. Continue to rotate until the cylinder is glowing red and starts to reduce in size or collapse. However, do not let the neck end of the cylinder get as red or the cylinder will be hard to manipulate.
2. Remove it from the flame, holding vertically, and give it a quick snap to align the cylinder. Blow steadily into the blowpipe end to a full ball, while rotating. Do not overblow. The ball must be annealed at this point. ANNEALING
Annealing is the process by which brittle glass is toughened by heating and slow cooling. For the Glaskolben, the annealing temperature is 900-950°F [510°C]. Kiln annealing is the most reliable method of annealing. The kiln control can be set for the desired annealing temperature and run for 20 minutes or more. The amount of time after 20 minutes makes no difference. One cannot over anneal. Leave product in kiln to cool slowly.
REMOVING THE BLOWPIPE END
After the ornament has annealed, the blowpipe end can be removed. The best method is using a Carbide Scribe. With this tool in one hand and the ornament in the other, press the sharp side of the carbide steel against the blowpipe neck and the thumb of the same hand pressing against the other side, rotate the shape while scoring the neck. Still holding the ornament, tap the blowpipe end to break it off. An ornament cap and loop can be attached to the ornament to finish it off.
DECORATING THE BALL
To decorate your glass ball, you can paint the surface with Pebeo Vitrea 160 paints, designed specifically for glass. Once painted, they should be baked in an oven at 325°F. [see Pebeo Vitrea 160 instructions].
You can also decorate your ornament using colored frit or powders. Fill to approx. 1/5 of the cylinder or just beyond the bend. Rotate the Glaskolben in the same manner as with the glass ball. It will take a little longer to bring the ball to blowing temperature because of the added volume of melting frit. The result is worth the added time.
A variation on the use of frit and powder is the method the production European blowers use when they add sugary snow on the ornament. Place some frit or powder in a wide flat bowl or saucer, roll the hot cylinder over the grit then reheat the frit covered cylinder in the flame. Blow into shape.
Stringers or Noodles (produced by Uroboros or Bullseye and available in 90 C.O.E.) offer another form of surface decoration. Select one, and while rotating the HOT Glaskolben counterclockwise (turn away from you) in the flame, heat the tip of the stringer in the flame. Place it under the cylinder, attach it and then allow it to trail around the cylinder. The stringer may be burned off at the finished end.
The point of the stringer may also be applied to the ball at 90° to dimple the surface.
