Slumping for Camera Cases
I am not skilled at slumping. Shallow things are fine, but I need to practice more with deeper shapes.
Flow Slab #1
I’ve been making some slabs, and replacing my saw with one that works, rather than my Castorama Chippy MacChipperson tile saw. It arrives yesterday while I was in Paris, visiting a friend who was there for the weekend, and the Art Paris Art Fair, and Paris Art Design. It’s a Gemini Apollo ring saw, and I’m in love. The blades are fragile, and I’m a dolt who already snapped one, but the finish is lovely, and there’s no chipping. So, here are pictures of one of my slabs, solid, cut up, and laid out in the kiln. I’m looking forward to seeing it when it’s all fired up.
The first firing was 1.3kg of glass, with a mix of blues, grays, and reactive glasses, the firing program was:
1. 167C/H to 663C hold 1:00
2. 333C/H to 810C hold 1:45 (since there is 0313, which should not be fired above 810C)
3. AFAP to 482C hold 3:00
4. 25C/H to 427C hold 0:01
5. 45C/H to 371C hold 0:01
6. 150C/H to 21C hold 0:01
The second firing, after everything was cut up and laid out is:
1. 334C/H to 289C hold 0:20 (to cure the shelf primer)
2. 222C/H to 677C hold 0:30
3. 333C/H to 804C hold 0:10
4. AFAP to 482C hold 0:30
5. 83C/H to 371C hold 0:00
6. AFAP to 21C hold 0:00
and, there will be more to come when it comes out of the kiln.
Brain and Heart
The molds were made of 60% silica and 40% plaster.
These molds were fired on the following schedule:
1. 5:00 – 125
2. 20:00 – 150
3. 30:00 – 650
4. 35:00 @ 650
5. 35:01 – 900
6. 40:00 @ 900
7: 49:01 – 515
8. 53:00 @ 515
9. 79:00 – 390
10. 92:00 – 20
The Molds went in on Monday March 30th, and came out on Sunday April 5th.
Brain 4kg furnace pellets. Water displacement: 7.4kg, wax 1.2kg.
Usually, the ratio for wax:glass has been 1:3 roughly, but this time is was 1:7, which both Orion and I thought was strange, so I put less glass in the flower pot for fear of overflow.
Heart 3kg furnace pellets. I forgot to water displace the heart, but I rememberd that it weighed approx 3/4 of the brain in wax.
5 birds each with 170g frit from casting furnace.
Abstract, wax 101g, mold packed with 294g Tea coloured cullet.
I used flowerpots on the Heart, Brain and the abstract.
When the firing was finished, there wasn’t enough glass in either the heart of the brain, obviously I should have suck to the water displacement amount of glass, it seems that that was right.
I couldn’t re-fire, since the brain mold split horizontally when I lifted it out f the kiln, and the heart mold was too fragile. Also, the locks inside the mold lost their bars somehow (probably during steaming?) and floated off the inside of the mold. There is therefore a lot of stress in the glass around them.
all the images associated with this firing can be found in the following album:
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| Brain and Heart |
Another possibility for this firing was as follows (this was the firing for Vanessas “Hand Hive”):
1. 5:00 – 125
2. 15:00 – 150
3. 22:00 – 650
4. 27:00 @ 650
5. 27:01 – 845
6. 32:00 @ 845
7: 32:01 – 515
8. 41:00 @ 515
9. 59:00 – 390
10. 68:00 – 20
Clear Bowl and Goblet Stem
For the Bowl, the wax mold was attached to a clay reservoir. The weight of the wax was 192g, and by water displacement, equivalent to 571g of clear System 96 furnace pellets, and I used that glass in the mold.
The mold was 7″ x 7″, 60% Silica, 40% Plaster, and poured.
For the goblet Stem, the wax mold was again attached to a clay reservoir. The mold was 4.5″ x 5″, poured into a plastic pineapple container. The wax weighed 89g, and was equivalent to 270g of furnace pellets, for the casting, I used 275 clear cullet, and 20g powder (Colour RW HP229).
Both molds were poured and steamed on December 1st, and Firing started on December 1st in Kiln #4 on the following schedule:
1. 3:00 – 150
2. 15:00 @ 150
3. 22:00 – 515
4. 25:00 – 600
5. 25:01 – 875
6. 30:00 @ 875
7: 30:01 – 515
8. 38:01 @ 515
9. 55:01 – 400
10. 68:00 – 50
More pictures are available here:
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| Bowl and goblet stem |
The goblet stem was picked up in the hotshop on December 9th, it was sent up to 515C over the course of 5 hours, then soaked for one hour, then sent up to 560C before being picked up and attached to a bubble and re-annealed on a normal annealing schedule for blown work in our studio.
Bird #1
The original for this piece was wax, 9cm x 4.5cm x 5cm. The mold had a built in reservoir made out of clay. The mold was 60% Silica, 40% Plaster, and poured on Sunday November 23rd.
I measured 210g of cullet by water displacement, and filled the mold and reservoir with 191g of clear System 96 furnace glass and 34g fine ivory Powder (G102 FP).
The mold stayed intact through firing, on the following full-melt schedule:
1. 1:00 – 100
2. 14:00 @100
3. 21:00 -515
4. 24:00 – 600
5. 24:01 – 875
6. 31:00 @ 875
7. 31:01 – 515
8. 46:01 @ 515
9. 76:01 – 400
10. 100:00 – 50
The schedule was much longer than required for this size of piece because it was maximized for the largest piece in the kiln, which was Robyn’s spiked piece. The melt time was longer in order to make sure that the spikes filled, and the annealing time was long, because that piece was much larger than mine, and more fragile, so the program was very conservative.
More pictures of the process are here:
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| Bird #1 |
There were a couple of brown spots on the back of the bird after firing, which may mean that I didn’t steam the wax out of the mold well enough, or that the clear or ivory powder were contaminated.
Fusing for Engraving
These were fired in kiln #2, with the following schedule:
1. 3:00 – 538
2. 3:01 – 793
3. 3:31 @ 793
4. 3:32 – 538
5. 4:00 – 516
6. 5:30 – 427
7. 10:00 – 50
They were put in, Monday November 10th, and came out Wednesday November 12th.
There were four shelves, the bottom shelf was two layers of grey over one layer of white. The second shelf up was two layers of steel blue over one layer of white. Each of those shelves were pieces that were 10″ x 6.5″. The third shelf up were smaller samples, one was cream on the bottom, grey, then black, and the other was black on the bottom, grey and then white. The top shelf was small two-layer colour samples. All the glass was Spectrum System 96 tested 3mm sheet.
After firing, the bottom layer had a lot of bubbles between the layers of glass. In the future, I will try the following firing schedule in order to reduce bubbles:
1. 5:00 – 590
2. 5:30 – 660
3. 6:00 @ 660
4. 7:00 – 710
5. 7:01 – 800
6. 7:31 @ 800
7. 7:32 – 540
8. 8:00 – 513
9. 9:30 @ 513
10. 13:30 – 427
11. 19:30 – 50
Also, the second shelf up cracked in one of the corners. Probably because I didn’t kiln wash the dams that I used around the fusings properly.
All the pictures from the process are in the following album.
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| Fusing #1 |
I intended to engrave all the pieces, but the two larger ones were cracked or bubbled. I did engrave the smaller samples, but the one that was black on top, did not work very well, in the future, I will make sure the have to top colour be thinner than the bottom one, as cutting through the two layers of dark colour to the lighter colour on the bottom left the back layer too thin, and forced me to cut away too much glass. The image at the top of this post is of the finished engraving on the sample that was white on top.
