This table is based on James Kirwin’s work on bead making with variations. This is for cold beads being heated for a secure anneal.
Up to 10mm dia.: afap to 530C, 30 mins; cool at 280C/hr to 360C; 840C to 40C.
12mm dia.: Go at 1000C/hr to 530C, 30mins.; cool at 194C/hr to 360C; at 580C/hr to 40C
14mm dia.: Go at 1000C/hr to 530C, 30mins.; cool at 142C/hr to 360C; at 425C/hr to 40C
16mm dia.: Go at 870C/hr to 530C, 30mins.; cool at 109C/hr to 360C; at 330C/hr to 40C
18mm dia.: Go at 690C/hr to 530C, 30mins.; cool at 86C/hr to 360C; at 260C/hr to 40C
20mm dia.: Go at 560C/hr to 530C, 30mins.; cool at 70C/hr to 360C; at 210C/hr to 40C
22mm dia.: Go at 460C/hr to 530C, 30mins.; cool at 57C/hr to 360C; at 175C/hr to 40C
24mm dia.: Go at 390C/hr to 530C, 30mins.; cool at 48C/hr to 360C; at 145C/hr to 40C
30mm dia.: Go at 245C/hr to 530C, 36mins.; cool at 31C/hr to 360C; at 95C/hr to 40C
38mm dia.: Go at 155C/hr to 530C, 39mins.; cool at 19C/hr to 360C; at 60C/hr to 40C
50mm dia.: Go at 90C/hr to 530C, 46mins.; cool at 12C/hr to 360C; at 36C/hr to 40C
Remember this table is for spheres. For cylinders choose the diameter that is 1.5 times the diameter of your cylinder, and for flat shapes choose the diameter that is 3 times the thickness of your piece.
For other information on annealing of beads go here
Friday, 30 July 2010
Monday, 26 July 2010
Bead Annealing Schedule for Bullseye Beads
This table is based on James Kirwin’s work on bead making with variations. This is for cold beads being heated for a secure anneal.
Up to 10mm dia.: afap to 540C, soak for 30min., cool at 300C/hr to 370C; afap to 40C.
12mm dia.: 1000C/hr to 540C, soak for 30min., cool at 220C/hr to 370C; 600C/hr to 40C
14mm dia.: 1000C/hr to 540C, soak for 30min., cool at 165C/hr to 370C; 480C/hr to 40C
16mm dia.: 1000C/hr to 540C, soak for 30min., cool at 125C/hr to 370C; 375C/hr to 40C
18mm dia.: 900C/hr to 540C, soak for 30min., cool at 100C/hr to 370C; 300C/hr to 40C
20mm dia.: 600C/hr to 540C, soak for 30min., cool at 80C/hr to 370C; 240C/hr to 40C
22mm dia.: 535C/hr to 540C, soak for 30min., cool at 67C/hr to 370C; 200C/hr to 40C
24mm dia.: 450C/hr to 540C, soak for 30min., cool at 55C/hr to 370C; 165C/hr to 40C
30mm dia.: 280C/hr to 540C, soak for 36min., cool at 36C/hr to 370C; 110C/hr to 40C
38mm dia.: 180C/hr to 540C, soak for 36min., cool at 22C/hr to 370C; 66C/hr to 40C
50mm dia.: 100C/hr to 540C, soak for 46min., cool at 13C/hr to 370C; 36C/hr to 40C
Remember this table is for spheres. For cylinders choose the diameter that is 1.5 times the diameter of your cylinder, and for flat shapes choose the diameter that is 3 times the thickness of your piece.
For other information on annealing of beads go here
Up to 10mm dia.: afap to 540C, soak for 30min., cool at 300C/hr to 370C; afap to 40C.
12mm dia.: 1000C/hr to 540C, soak for 30min., cool at 220C/hr to 370C; 600C/hr to 40C
14mm dia.: 1000C/hr to 540C, soak for 30min., cool at 165C/hr to 370C; 480C/hr to 40C
16mm dia.: 1000C/hr to 540C, soak for 30min., cool at 125C/hr to 370C; 375C/hr to 40C
18mm dia.: 900C/hr to 540C, soak for 30min., cool at 100C/hr to 370C; 300C/hr to 40C
20mm dia.: 600C/hr to 540C, soak for 30min., cool at 80C/hr to 370C; 240C/hr to 40C
22mm dia.: 535C/hr to 540C, soak for 30min., cool at 67C/hr to 370C; 200C/hr to 40C
24mm dia.: 450C/hr to 540C, soak for 30min., cool at 55C/hr to 370C; 165C/hr to 40C
30mm dia.: 280C/hr to 540C, soak for 36min., cool at 36C/hr to 370C; 110C/hr to 40C
38mm dia.: 180C/hr to 540C, soak for 36min., cool at 22C/hr to 370C; 66C/hr to 40C
50mm dia.: 100C/hr to 540C, soak for 46min., cool at 13C/hr to 370C; 36C/hr to 40C
Remember this table is for spheres. For cylinders choose the diameter that is 1.5 times the diameter of your cylinder, and for flat shapes choose the diameter that is 3 times the thickness of your piece.
For other information on annealing of beads go here
Labels:
Annealing,
Beads,
Fused Glass in Glasgow,
Verrier
Thursday, 22 July 2010
Bead Annealing Schedule for Borosilicate Beads
This table is based on James Kirwin’s work on bead making with variations. This is for cold beads being heated for a secure anneal.
Up to 10mm dia: afap to 570C, soak 30 mins; anneal at 900C/hr to 500C; afap to 40C
12mm dia: 1000C/hr to 570C, soak 30mins; anneal at 630C/hr to 500C; afap to 40C
14mm dia: 1000C/hr to 570C, soak 30mins; anneal at 468C/hr to 500C; 1000C to 40C
16mm dia: 1000C/hr to 570C, soak 30mins; anneal at 355C/hr to 500C; 1000C to 40C
18mm dia: 1000C/hr to 570C, soak 30mins; anneal at 280C/hr to 500C; 840C to 40C
20mm dia: 1000C/hr to 570C, soak 30mins; anneal at226C/hr to 500C; 675C to 40C
22mm dia: 1000C/hr to 570C, soak 30mins; anneal at 187C/hr to 500C; 560C to 40C
24mm dia: 1000C/hr to 570C, soak 30mins; anneal at 157C/hr to 500C; 470C to 40C
30mm dia: 800C/hr to 570C, soak 36mins; anneal at 100C/hr to 500C; 300C to 40C
38mm dia: 500C/hr to 570C, soak 39mins; anneal at 60C/hr to 500C; 180C to 40C
50mm dia: 285C/hr to 570C, soak 46mins; anneal at 36C/hr to 500C; 100C to 40C
Remember this table is for spheres. For cylinders choose the diameter that is 1.5 times the diameter of your cylinder, and for flat shapes choose the diameter that is 3 times the thickness of your piece.
For other information on annealing of beads go here
Up to 10mm dia: afap to 570C, soak 30 mins; anneal at 900C/hr to 500C; afap to 40C
12mm dia: 1000C/hr to 570C, soak 30mins; anneal at 630C/hr to 500C; afap to 40C
14mm dia: 1000C/hr to 570C, soak 30mins; anneal at 468C/hr to 500C; 1000C to 40C
16mm dia: 1000C/hr to 570C, soak 30mins; anneal at 355C/hr to 500C; 1000C to 40C
18mm dia: 1000C/hr to 570C, soak 30mins; anneal at 280C/hr to 500C; 840C to 40C
20mm dia: 1000C/hr to 570C, soak 30mins; anneal at226C/hr to 500C; 675C to 40C
22mm dia: 1000C/hr to 570C, soak 30mins; anneal at 187C/hr to 500C; 560C to 40C
24mm dia: 1000C/hr to 570C, soak 30mins; anneal at 157C/hr to 500C; 470C to 40C
30mm dia: 800C/hr to 570C, soak 36mins; anneal at 100C/hr to 500C; 300C to 40C
38mm dia: 500C/hr to 570C, soak 39mins; anneal at 60C/hr to 500C; 180C to 40C
50mm dia: 285C/hr to 570C, soak 46mins; anneal at 36C/hr to 500C; 100C to 40C
Remember this table is for spheres. For cylinders choose the diameter that is 1.5 times the diameter of your cylinder, and for flat shapes choose the diameter that is 3 times the thickness of your piece.
For other information on annealing of beads go here
Labels:
Annealing,
Beads,
Fused Glass in Glasgow,
Verrier
Sunday, 18 July 2010
Bead Annealing
There are two approaches to annealing beads.
One is to keep them warm as you make them and when the session is finished, anneal all the beads sitting in the kiln. Assuming you are using soda lime glasses rather than borosilicate, you need to have the kiln idling at around 500C. When you have evened the heat throughout the bead, you place it in the kiln. Gloves and other heat protection attire will be needed when you open the door/lid to put the bead on the mandrel into it.
When you have finished the bead making session, you then take the temperature up to about 520C – 540C and soak there for about half an hour – both depend on the type of glass and the thickness and shape. The object is to take the glass up to a temperature where the annealing process can work, but without being so high in temperature that the bead takes up marks from the kiln shelf. More information on the soak and annealing of various shapes, sizes and types are given in later tips.
The second method applies if you have cooled the beads in vermiculite, blanket or other means to cool them slowly and you now have a group of cold beads that you wish to ensure are correctly annealed. You need to start the kiln from cold. Place the beads in the kiln and begin the firing. You need to take the beads up slowly – not more than 300C/hr - to between 520C and 540C, and soak there for about an hour. More information is given in further tips.
In both the cases described you now have the beads with the temperature equalised throughout the bead, and the annealing can begin. The annealing is the controlled cooling below the annealing soak. It is generally safe to take the temperature down at about 80C/hr to 360C. After this point you can speed up the cool down to something like 200C/hr, or if you kiln cools slowly enough, just turn it off and wait for the temperature to come down toward room temperature. This again depends on the type of glass, its size and shape.
Variations according to glass type used, sizes and shapes follow in further tips.
Annealing of Borosilicate Beads
Annealing of Bullseye Beads
Annealing Effetre Beads
Annealing Spectrum 96 Beads
Effect of Shape
Effect of Size
Effect of Variations in Sizes
One is to keep them warm as you make them and when the session is finished, anneal all the beads sitting in the kiln. Assuming you are using soda lime glasses rather than borosilicate, you need to have the kiln idling at around 500C. When you have evened the heat throughout the bead, you place it in the kiln. Gloves and other heat protection attire will be needed when you open the door/lid to put the bead on the mandrel into it.
When you have finished the bead making session, you then take the temperature up to about 520C – 540C and soak there for about half an hour – both depend on the type of glass and the thickness and shape. The object is to take the glass up to a temperature where the annealing process can work, but without being so high in temperature that the bead takes up marks from the kiln shelf. More information on the soak and annealing of various shapes, sizes and types are given in later tips.
The second method applies if you have cooled the beads in vermiculite, blanket or other means to cool them slowly and you now have a group of cold beads that you wish to ensure are correctly annealed. You need to start the kiln from cold. Place the beads in the kiln and begin the firing. You need to take the beads up slowly – not more than 300C/hr - to between 520C and 540C, and soak there for about an hour. More information is given in further tips.
In both the cases described you now have the beads with the temperature equalised throughout the bead, and the annealing can begin. The annealing is the controlled cooling below the annealing soak. It is generally safe to take the temperature down at about 80C/hr to 360C. After this point you can speed up the cool down to something like 200C/hr, or if you kiln cools slowly enough, just turn it off and wait for the temperature to come down toward room temperature. This again depends on the type of glass, its size and shape.
Variations according to glass type used, sizes and shapes follow in further tips.
Annealing of Borosilicate Beads
Annealing of Bullseye Beads
Annealing Effetre Beads
Annealing Spectrum 96 Beads
Effect of Shape
Effect of Size
Effect of Variations in Sizes
Labels:
Annealing,
Beads,
Fused Glass in Glasgow,
Verrier
Wednesday, 14 July 2010
Removing Beads Stuck to the Mandrel
You may need to hold the mandrel in pliers or in vice grips while holding the bead with a scrubbing pad or jar opening rubber pad.
If this does not work, try soaking the bead and mandrel in water for a few hours. This often is enough to release the bead.
A little more drastic method is to then place the bead and mandrel in the freezer. After being frozen, the bead will most often come off as the water in the bead release thaws.
A final attempt can be made with a pop rivet gun. Insert the mandrel and operate the levers, and it will push the bead off the mandrel.
If all other things fail and you really want your mandrel back, you can warm the bead in the flame and dump it in water. It will break apart with the shock from the water. You can then clean up the mandrel for future use.
If this does not work, try soaking the bead and mandrel in water for a few hours. This often is enough to release the bead.
A little more drastic method is to then place the bead and mandrel in the freezer. After being frozen, the bead will most often come off as the water in the bead release thaws.
A final attempt can be made with a pop rivet gun. Insert the mandrel and operate the levers, and it will push the bead off the mandrel.
If all other things fail and you really want your mandrel back, you can warm the bead in the flame and dump it in water. It will break apart with the shock from the water. You can then clean up the mandrel for future use.
Saturday, 10 July 2010
Bubble Squeeze
One of the most effective ways of reducing bubbles is to adjust the schedule to allow the top glass to slump down onto the bottom sheet before the glass is soft enough to stick at the edges and trap air. This is commonly referred to as a “bubble squeeze”.
A common method is to insert a soak at the slumping temperature of the glass. You will have found that the glass will take up the form of a simple slump at a lower temperature than more angular forms. Use this lower temperature for 30mins to an hour. You may want to extend that soak time depending on the thickness and complexity of the layup.
Another method is to start the squeeze about 55C above the annealing soak temperature and increase the temperature slowly (27-55C per hour) until you are at the slump temperature.
You can also combine the two above methods by soaking at the slump temperature for 30 minutes to an hour – or longer for thick and complex pieces – after the slow rise.
If your kiln is a side fired one, you need to be especially careful, as the edges of the glass become hotter than the centre. Two options are available - fire more slowly, or place baffles around the outside of the piece to prevent direct radiation of the heat onto the edge of the glass.
A common method is to insert a soak at the slumping temperature of the glass. You will have found that the glass will take up the form of a simple slump at a lower temperature than more angular forms. Use this lower temperature for 30mins to an hour. You may want to extend that soak time depending on the thickness and complexity of the layup.
Another method is to start the squeeze about 55C above the annealing soak temperature and increase the temperature slowly (27-55C per hour) until you are at the slump temperature.
You can also combine the two above methods by soaking at the slump temperature for 30 minutes to an hour – or longer for thick and complex pieces – after the slow rise.
If your kiln is a side fired one, you need to be especially careful, as the edges of the glass become hotter than the centre. Two options are available - fire more slowly, or place baffles around the outside of the piece to prevent direct radiation of the heat onto the edge of the glass.
Labels:
Bubbles,
Fused Glass in Glasgow,
kiln forming,
Verrier
Tuesday, 6 July 2010
Uneven Heating Effects
If the glass is heated unevenly, it can lead to bubbles between the shelf and the glass, causing large bubbles with thin structures, if not actually burst. This can happen especially with side or side and top firing kilns. The solution to this is to [baffle] the edges of the glass from the direct heat of the elements.
Labels:
Bubbles,
Fused Glass in Glasgow,
kiln forming,
Verrier
Friday, 2 July 2010
Rapid Firing Effects
Bubbles between the glass and the shelf can be caused by firing too quickly. Fast firings can cause the glass at the edge to soften early and trap air underneath the glass. At fusing temperatures the air blows a bubble through the glass. Solutions for this are described in
[bubbles between the glass and the shelf]
[bubbles between the glass and the shelf]
Labels:
Bubbles,
Fused Glass in Glasgow,
kiln forming,
Verrier
Subscribe to:
Posts (Atom)