Matt Glazes on Porcelain

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These are the same variations on a dolomite matt glaze as in the last glaze post. This time they’ve been fired on porcelain in oxidation 1280C. W2 (with soda feldspar) has the best white result, W1 being shinier and less brightly white while W3 has yellowish undertones. B2 is the exact kind of deep matt black I was looking for too, B1 still having a green tinge in oxidation. I’m either going to start hand building with thrown porcelain sections of covering the stoneware sculptures in porcelain slip to get these glaze results.

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Matt Glazes Cone 10.R

Thinking about the surface effects I’ve identified I liked in the past I found a Mamo Matt glaze in Jeremy Jernegan’s Dry Glazes handbook and made the following variations:

Original: MC36 (W1)
Potash feldspar                     50
Dolomite                                 20
Whiting                                   4
Calcined china clay              21
Tin oxide                                 5

W2 – Replaced feldspar with 50 Soda feldspar
W3 – Replaced feldspar with 50 Nepheline Syenite
B1 – Original recipe with 1% cobalt, 8% black iron and 3% manganese
B2 – Original recipe with 4% black glaze stain

Fired in Reduction to 1280C. It was surprising to see how just changing the feldspars could change the colour so much. The potash gives a brighter, more clinical white than soda while the nepheline syenite gives blushes of pink and orange. The manganese gives a matter, more metallic black than the stain which gave more of a dark green undertone. I like the manganese black glaze (below) a lot because of the oily way it reflects the light without being too shiny. Application is better when poured.

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Below is the piece I worked on over the weekend, throwing in sections with white st Thomas then joining them together on the wheel when leather hard. Already you can see a wide ranges of tones of light and shadow and a series of ellipses when looking through the form. I enjoyed the process of making this piece and the way the pieces slotted together like a jigsaw puzzle.  The next step is to make more of these composite forms but trying to make them less symmetrical and on a smaller scale (maquette size).

 

 

Identity

After visiting the Potteries museum in Stoke last week, visiting the V&A in London yesterday and looking at my own personal collection of ceramics, I’m beginning to see trends and patterns in the work I am drawn to and like to surround myself with. Much of my work in the first year was stuff I enjoyed making but didn’t necessarily like. By pinpointing styles and techniques I find attractive I hope to make work I can feel proud of and that speaks more clearly of me. 

Looking through my sketchbooks, notes and photos I’ve identified some key recurring themes and styles which I’m drawn to. Hopefully this can be a starting point for exploration when I return to university next month:

  • White glaze on black clay
  • Celadons
  • Dry glazes
  • Altered vessels
  • Asymmetry
  • Thrown forms

And now for some bowls

 

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For some reason I find throwing and turning bowls more difficult than other forms. I can never seem to get the thick clay out of the base and they tend to end up with strange ridges. The pearlescent glaze here was supposed to be a gloss white but looks like it needed more than one layer.

Page 132 The Glaze Book – Gloss white 1290C

Potash feldspar                              60
Dolomite                                         20
Quartz  (flint)                                 15
China clay                                       5
Rutile                                                5

Layered on top of another glaze the opalescent effect might work but I don’t like how watered down it looks revealing the clay underneath here.

The bowl with the oatmeal glaze is my favourite – it’s got rings of different shades of orange with a subtle texture and green tinging where it’s pooled at the base. I like the detail of the running green glaze around the rim too – a touch of Lucie Rie!

Oatmeal 1290C

Potash feldspar                             45
Dolomite                                         88
Quartz    (flint)                               16
Zirconium silicate                         11
China clay                                        6
Zinc oxide                                        2
Chrome oxide                                 1

The green bowl has a pleasant mottled antique green colour – white slip with smooth satin opaque yellow green on top applied to bisque ware. I like the visible brush marks and the colour variation where the thickness is different.

I created a monster

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Here we are, right at the end of the year, and I finally feel I’ve found a process which really excites me. Combining throwing and hand-building I get the benefit of enjoying two very different techniques – the throwing is cathartic, a quick way of making lots of forms that hold space, then the hand-building is like a giant jigsaw puzzle, intuitive, taking careful consideration of the balance and weight of the piece.

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Work in progress

I want to see how far I can push this technique, how big I can build. The individual sections can be thrown fairly quickly, the slow process is the controlled drying and fitting together. Considering pieces were falling off even on this scale, it will be a challenge to create large scale work but I’m eager to try it. I might get hold of a heat gun to have more control over drying, secure joints with extra clay and use foam to prop up the structure as I’m working on it. The final centrepiece above feels organic, like a piece of driftwood or seaweed, but at the same time the even throwing lines and geometry of the form reference the industrial. I had some trouble with sections falling off before firing and during the raku as I tried to pull them out of the sawdust. Fortunately I could get them to stick back together with some epoxy. If building one large sculpture this way is too much trouble I can always fire lots of pieces separately then glue them together afterwards.

The glaze I made was intended to be blue, the same duck egg raku glaze I’ve used before (see recipe here) (with the omission of about 10% of the Tin oxide because it ran out). To get in the awkward nooks and crannies of the concave and convex forms I decided it would be easiest to use the spray gun. I’ll be using the spray booth a lot more often now I realise how easy it is.

I was surprised when the glaze came out of the sawdust a dark pink/purple but I expect it’s to do with ferric chloride left over in the kiln lining from previous firings. I’m pleased with the unexpected results – where the flame has licked the work it’s turned metallic silver and the surface has character and variation with patches of yellow, white, black and texture among the pink and purple. It reminds me a bit of an octopus or a squid reaching its suckers out to grasp its prey, or a homemade robot from Robot Wars. There’s something hostile and dangerous about it, perhaps because of the dark colour. The shadows created with the light from above in the photos give the sculpture a gravity defying look, as if parts are floating. Duncan suggested I should experiment with placing lights inside to see how different shadows can be cast.

This project has definitely been more process driven than idea orientated. Because of the raku there’s something dirty-looking, perhaps ugly about the piece. In the context of a centrepiece this links back to ideas I had at the beginning about dirty dishes. It’s not something that would put your mind at ease during a meal, for me it conjures up anger or a raging storm. I began by calling it a monster but maybe a storm would be more appropriate. It interests me that it looks very different depending on where you sit at the table. It’s dynamic, like the conversation at a good dinner table should be or it might also reference broken crockery. I’ve moved very far away from my original ideas of an interactive, functional object. I hope it would be an inspiring conversation starter.

 

Pop art oil lamps – glazed

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I finally got around to glazing the pop art inspired oil lamps we made earlier on this year with Mick Morgan. The bisque fired vessels have been painted with this clear stoneware glaze from the Emmanuel Cooper glaze handbook:

High alkaline frit                                                    10
Standard borax frit                                                50
Ball clay                                                                    30
Cornish stone                                                           10

I was worried the stains in the coloured slips might burn out at 1280C but luckily they stayed bright. The blue is a lot darker than I expected but works as a dramatic contrast to the pastel colours and I like how the colours and pattern unite them as a set. Perhaps they would look better decorated with matt vitreous slips though, or with a variation of block colour and line drawings, a kind of collage of slips and decals. I preferred the matt surfaces of the bisque ware to the shininess they have now. My favourite view of them is the abstracted one from above – the circles of different colour create a fun composition.

 

Natural glazes

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I’ve been invited to sell my work in my local hometown and want the glazes to reflect the colours of the rural landscape of North Wales. These thrown vessels have been painted with the glazes I made at the start of the year as part of the local clay project. The bowl has been pained with a glaze made from a 2:3 ratio of Potash feldspar to my clay while the rounded pot has a 2:1 mixture of Whiting and my clay. It flows very much like an ash glaze but luckily wasn’t too runny that it stuck to the kiln shelf. I’m going to add more whiting and feldspar to these glazes because the colours are much darker than I expected.