| || || || This is another example of me using segments to make larger scale sculptures (see "Column" and "Light Waves" for other examples). In this case, I'm trying to make a large (90-cm-diameter) hollow ring by slip-casting 12 segments. Note the "trying". I've been trying off and on since January 2011 and
things haven't gone smoothly. The clay collapsed inside the mould in a
lot of cases but I've now solved the problem thanks to advice and
chemicals from Maria Psiliagkou, a ceramics technician at Plymouth
College of Art.|| |
| || || ||First stage was to make a wooden version of the segment (foreground) and
a box to contain it (background) to pour a plaster mould. || |
| || || ||I made the plaster mould in 2 steps to create a box and lid. |
drilled two 75-mm holes in the side to pour the slip in and out. Later
on, I joined the holes up to make a bigger hole for the slip to escape.
scratched a date on the side when this was complete - 11th January
2011. In other words, this project has had many inactive periods!
| || || ||Here's my set-up for pouring slip. Polythene on floor. Mould clamped
together on planks beneath which is a tray and empty pots to catch slip
when it's poured out. |
Slip is mixed with electric drill in the cardboard box on the left (to stop spray).
| || || ||The mould is filled with slip and left for a couple of hours. Early on I
tried leaving it for a lot longer - overnight in one case - to try and
After a couple of hours, I turn over the mould and let the slip spew out over the pots and tray beneath it. I
roll the mould back so the hole is uppermost after several hours.
After a couple of days I remove the clay around the opening, put some
props inside and leave it dry for about a week before removing the segment from the mould.
| || || ||This is one of the more successful early segments. A lot of them were
failures. The clay peeled away from the walls and collapsed inside the
After a disaster I'd be so fed up I'd move on to other projects, sometimes for several months at a time.
| || || || An early completed segment. |
I've now joined the holes up in the mould to make it easier to
remove the slip and I've made the slip a lot less viscous by adding
water and chemicals (sodium silicate and soda ash).
As a result, the
last 8 castings have been successful. The walls of the segments are
much thinner - hope they're not too thin!
| || || || I've now made 13 segments - one extra to allow for breakages and possible replacement of an early one that I had to "repair". I've checked out what the ring will look like - see photo. |
All the segments have now been biscuit fired (by Jenni Phillips).
I'm now waiting for the spray booth at college to be working so I can glaze them.
| || || ||I've added this photo after discussing the ring's location with Chris Taylor, ceramics lecturer at Plymouth College of Art. Chris demonstrated the importance of considering the context in a tutorial with me - which I've written up in this blog entry.|
The ring will go right at the end of this elevated walkway, where it stops above our neighbour's fence. You walk along this walkway to get to our front door, where the glass canopy is.
| || || ||I've now glazed all 13 segments. Three came out of the kiln today (11th Dec). The glaze is mildly disappointing. It was advertised as "glossy white large crackle" but it's come out simply white - no crackle in sight. Also, there's a few small bald patches but they're good enough for the garden. The other 10 are being fired - will be out on Friday. My plan is to erect the ring over Xmas - 3 years since I started this project!|| |
| || || ||I decided to scrap 2 of the segments that cracked badly during firing of the glaze, which meant that I couldn't assemble the ring over Xmas as planned. (In any case, I was busy slip-casting dozens of figures for my Faces project.)|
In the past couple of months I've made and glazed another segment and today I've started to assemble the whole thing on the workshop floor (picture) and stick them together with mastic/glue.
| || || ||I ended up placing the segments on top of an extended door so that I could swing it upright without putting a lot of strain on the half-finished joints.|
I stuck a piece of rubber carpet underlay between each segment to try and avoid points of high pressure.
I've now filled all of the joints with a thixotropic polyester resin paste mixed with black dye.
In this photo, I'm making clay mould above each joint to create neater looking joints, using some more polyester paste. I'm making them a constant width using a piece of metal band that's pinned to the centre of the ring. It's also enabling me to mask the fact that the segments don't butt up perfectly.
One other discovery - I've managed to lose a segment! There's only 11, and I wouldn't have been able to fit a 12th one in!
I think the end result will look like a clock so I'm now thinking of calling it something like "The Eleventh Hour" or "Not Enough Time."