Saturday 28 April 2018

Creating Coloured Porcelain

I have been experimenting with adding colour into porcelain slip. I've decided to colour the clay body, rather than adding a glaze or coloured slip on the surface, as I have been creating 3D textured pieces which I feel would lose their definition if I covered them. To get bright colours, quite a lot of underglaze needed to be added to the porcelain, because the porcelain is white, so all of the resulting colours would be tints.

I decided to test the colours at different temperatures as well as different concentrations of colour. Starting at 1g of underglaze to 100ml of porcelain slip, I also tested 2g, 3g and 5g. I poured out the slip onto plaster bats to dry, then cut each into 6 sections to fire at 1000, 1060, 1140, 1200, 1230, and 1260 degrees Celcius. I felt like this would give me a good overview of how the firing temperature and concentration alter the colour.

I used Picasso blue, black, turquoise, and lime green underglaze powders, and I plan to start mixing my own colours now I have a better idea of how they behave at different temperatures and concentrations. I remembered to label them before I fired them because I've made the mistake before of getting a beautiful result and forgetting how I got there!

I will make some texture tests with the coloured clay to see how the surface works with the colour, and I will also try putting underglaze powders into plastic clay rather than slip, to see if a uniform texture can be obtained by wedging it into the clay.

Sunday 12 April 2015

Mixing Glass and Copper

 Glass powder and flux heated from underneath to give a textured finish
 Layer of hot glass, pieces of copper, more glass dropped on top
 Copper wire encapsulated in hot glass
 Copper wire encapsulated in fused glass
 Copper sheet kiln fired with scrap glass pieces and coloured glass powder
Copper sheet kiln fired with glass powder on and to the side of it.

Through my testing I have noticed a familiar theme, which is mixing copper with glass. I think this could be a good theme to take forwards, experimenting more with shaping the copper before it gets put in the glass, and possibly patinating or texturing it after.

Kiln Glass: Using Powdered glass

I have been experimenting with using powdered glass (designed for use with hot glass) in the kiln. I found out that it is very unpredictable as it is so this and fine, so it melts and separates, giving different lacy textures and little strings and holes.
I took this further by also using glass stringers, glass frit, copper wire and copper sheet. I really like the surprise of opening the kiln and seeing what the powders have done.

Hot Glass: Moss

Inspired by the tiny bud shapes of this close up moss, I made a collection of glass shapes which are all slightly different but sit together.

I hope to make more of these glass pieces as both a way to improve my glass skills, and to make a piece to convey the idea of things in nature being similar, but never exactly the same.

Kiln Glass: Fusing

I collected green and orange glass from the hot shop scrap bins (clear glass is recycled but bits with colour are put in a bin which we can use for fusing, casting, slumping etc.) I chose to stick with this colour scheme as these are the colours of moss I have been looking at. I arranged the scraps on a kiln shelf which had been prepared with batt wash to stop the glass sticking, and to give them a smooth back. I arranged the pieces into shapes, and also put some bits of copper under the glass, inbetween layers and on the top, to see how it would react with the glass and the heat of the kiln.
These were just test pieces, but if i wanted to further this technique, I could make specific components in the hot shop, to then fuse together in the kiln. My favourites were the ones I made from the glass powder, as these had a more unpredictable texture, where the powder had melted and separated and left holes and gaps.

The copper worked well, changing colour to give different reds, maroons and black. I could cold work both the glass and copper, to put texture onto the glass or to change the colour of the exposed parts of copper to their original colour.

I feel that some of these pieces are fairly boring, as I controlled them too much. I think the ones that did something unexpected were good, as they made me think about where else I could take it, rather than creating a piece I was expecting.

Hot Glass: Prunts, Inclusions and imprints

 I first put copper in glass by dropping a blob of hot glass onto a graphite sheet, dropping copper onto that, then putting more glass over the top to trap the copper inside. This works, and I then moved onto doing this in 3D rather than on a flat surface.
The technique was the same, the second glass layer is dropped on top, as if the glass with copper on is put back in the furnace it could easily fall off and contaminate the glass.

I used the same method to create a hollow form with copper inclusions and colour.
I talked to simon about getting texture onto the glass and he told me about prunts, which are stamps used on hot glass. I used a raspberry shaped graphite stamp to shape a blob of glass.
I think a collection of these could be a nice mini installation.
 I then tried using real moss, and other bits of organic matter, to make imprints in glass. I dropped the glass on top of the pieces, which made them catch fire and smoke a lot, but the glass cooled quick enough to capture the texture before the plants burnt away.