Friday Night Fusing Clinic
October 14th, 2005 ... Pot Melts & Recycling System 96 into Cullet
Pot Melts:
Get a small clay pot, any garden/hardware store should carry them. Place your shelf on the bottom of the kiln, and cover it with Shelf Paper, thin Fibre Board or Lava Cloth. Create a bridge in your kiln with dams, posts, whatever you have that can survive in the kiln. Place the pot between the two top parts of your bridge, and fill with scrap System 96. You don't need to coat it's interior with kiln wash.
Use mostly clear scrap and only some colour. Darker cathedrals or opals will show better in the final product. Try to cut your scrap into narrow strips and place in the pot in a vertical orientation. Fire fast and a little hotter than full fuse, 1475 degrees, for at least 30 minutes.
Factors that will influence the size of your rondel are the target fusing temperature, the time at that top temperature, the size of the hole in the bottom of the pot(you can drill it out if you want)the colour of the glass the shorter the height, the larger your rondel.
The glass will melt in a circular pattern, looping around itself. Once it is cool, remove the pot and knock off the stem at the base with grozier pliers. Re-fire the rondel to smooth the top. You can re-use the pot a few times before it cracks, but you do have to use the same colours as the first time, and it will be a little slower flowing.
If you have the ability, make a stainless steel stand that will hold 1 or more pots for faster setting up in the kiln. If you have a Hot Box kiln, try to set up a small rig with bead mandrels, high temperature wire, and a few blocks of fire brick. Be very careful to keep the ends of the mandrels away from the elements in your kiln.
Recycling System 96 into Cullet:
Place your shelf in the kiln and lay down a sheet of 1/8" fibre paper and shelf paper a few inches larger all the way around than what you plan on casting. Cut a long narrow strip, about 1" wide, of the same fibre paper and place it on the shelf, in a vertical position, making a 'fence'. Place posts or dams around the fence to support all sides of the fence. Fill the interior of the fence with scrap System 96, mostly clear again, and some colours for the most vibrant appearance. You could use all opals and it would be different on all side. Try to fill inside the fence as equally as possible.
Fire long and hot, watching for the glass to level out. Program a long annealing phase, similar to slumping, but longer and slower. Once cool, remove the fibre paper. You may need to re-fire to get a fire polish, or cold work the sides to a smooth finish. Try cutting up the final piece with a saw to get interesting cross sections which you can then re-fuse into another piece.
This is the program used the first time we tried this. Once you've done this a few time, you should be able to calculate down to how thick your glass will end up, and work out an exact program for ideal annealing. The projects on our shelf were of various sizes and shapes, so this program is on the conservative side.
Using a Rampmaster II Controller:
5 Segments
| #1 | #2 | #3 | #4 | #5 |
| 1000 | 9999 | 999 | 20 | 100 |
| 1500 | 1000 | 950 | 750 | 100 |
| 60 | 30 | 120 | 10 | 1 |
Images
Demostration Pot Melt in the GT14.6 kiln
Doug & Cathy's Small Pot Melt in the GT14.6 kiln - Before
Doug & Cathy's 'After' Pot Melt. Please excuse the blurry image, no macro feature on our camera. The 'Rondel' is about 1.5" across.
Forms filled with scrap System 96 being fired in GTS 25.41 kiln
Results from Cullet projects
They all have had fibrepaper washed off the bottom and edges already. On all of the pieces, small sharp strands of glass clung to the fibrepaper walls. They can be knocked or ground off.
Larger pieces.
The tip of the largest one broke off. There was some seepage of glass underneath the fibrepaper walls, and onto the dams. Some glass stuck to the dams, but was knocked off easily.
Smaller Cullet projects, standing on edge.
As for what to do with these now, you could clean up the edges, re-fuse smooth, and have a nice paperweight, or fuse into another larger project as the centerpiece. You also cut saw it up into narrow strips, lay flat, and re-fuse into another project.
Larger Pot Melt Images
3 Medium sized pots, after firing
Side view of medium pots after firing. Note cracks in pot due to insufficient annealing
Below grade side view of 3 Medium sized pots, after firing. Notice that the stems cracked off from the rondels on all three, again, likely due to insufficient annealing program. Note, kiln was at room temperature when picture was taken. Do not try to take a picture from this angle when kiln is firing.
Firing Program, (with better annealing)
| #1 | #2 | #3 | #4 | #5 |
| 500 | 1500 | 9999 | 20 | 200 |
| 1000 | 1550 | 950 | 780 | 100 |
| 0 | 60 | 120 | 10 | 1 |
Top view of large pot after firing
Close up of large pot's rondel after firing. Once again, this picture was taken when the kiln was cool. Please do not attempt with kiln is firing!
3 medium sized rondels and large pot with stem and rondel still attached. The red and orange rondels have a much better spiral design as they had a good balance of coloured opal glass and clear scrap in the pot.
Follow up research on Pot Melts indicated that increasing the temperature would give a larger rondel. This was attempted with these pots. This did happen, but once the pots were back out of the kiln, the clay began to crack loudly. If this gets on your nerves, you can break the clay off with a hammer and try to salvage the glass inside to refuse it again. The stems were also thicker.
A different firing schedule was used on them:
| #1 | #2 | #3 | #4 |
| 1600 | 9999 | 999 | 20 |
| 1650 | 1000 | 950 | 750 |
| 20 | 30 | 180 | 5 |
#1 Two 4" clay pots, both filled with Spectrum 100DT scrap. The Left one also had a 230.76 Blue Opal Rod and a 260.72 Yellow Opal Rod, while the right one had 533.3SF Deep Aqua and 533.1SF Sky Blue in it.
#2 One 4" clay pot filled with Spectrum 100DT scrap, and scrap Spectrum 260.72SF Yellow Opal, and Uroboros 602702-96 Orange Opal. This pot was fired by itself in a GT14.6 for longer, and the rondel came out much larger.
3 Rondels after being removed from pots. The chunk of glass is from the pot that had the 2 blue colours in it. You can see the clay from the pot fused to the sides of the glass.
#3 Two 4" clay pots, filled with System 96 Studio Nuggets. The left pot was also filled with F-2 Fine 5333 Deep Aqua frit, while the right one was filled up with F2 Fine 220.76 Dark Green Opal frit. To fill up these pots with frit, you need to cut out a small disc of 100SFS clear and place it on the bottom of the pot as a cover, to prevent the frit from pouring back out the bottom.