Showing posts with label glaze. Show all posts
Showing posts with label glaze. Show all posts

Monday, September 12, 2011

Green Issues


A topic that is red hot in the media at the moment is the environment. We hear about global warming, energy conservation, depleting resources and recycling on a daily basis. As a child I learnt at school about gasses emitted by aerosol cans are causing a hole in the ozone layer, which can result in illnesses like skin cancer. At home that afternoon I neurotically begged my mother not to use deodorants as I feared for my life. Laughing it off because she came from a generation that was consumed by the conveniences of the post –war period, she merrily sprayed away. Besides, it would take such a long time to happen, there was no urgency in stopping then. Many years later we are facing the dilemma and all of a sudden we have switched to panic mode.
 
Green actually became a trend colour, in interiors, products, packaging and fashion. It became a visual way of reminding us to live more green. Even a large petroleum company increased its turnover, not because their product was more environmentally friendly, but because of making the public aware of its corporate colours. We now go into a supermarket buying organic products at a prime price just to ease our conscience.
 

Organic – the word also comes to mind when we talk about pottery – organic, wholesome, from the
earth – but is it really? We present our vessels to prospective buyers with a smile on our faces – ‘I
made this by hand, from the earth’ – should it then necessarily be good?
 
We work with raw materials that is actually quite hazardous. Often the fumes emitted during firing
drives us from our studios coughing and gasping for fresh air. How many of us actually wear respirators when working with glazes often containing deadly materials such as lead bisilicate or barium carbonate? In ancient times potters always outlived a few wives, who always had to decorate the pots, and the toxins from the lead used often killed them.
 
What could we do to make our craft more green? This could end up in a never ending debate, but a
few solutions come to mind. Pottery, once fired, lasts for a very long time. Archaeologists can tell the level of sophistication of a civilization merely by looking at the pottery they used, purely because it outlasts any other material. Once you made your piece, be very critical about it. If it is not your best and you are not proud of it, reclaim it before you fire it. After all, the joy is in the making. Nobody had any use for a clumsy, badly made pot that lies somewhere in a landfill.
 
Be more aware of the glazes we use. So often retail suppliers have glazes on their shelves that originates from the sixties. As long as it still sells, they will keep on producing it. A lot of these
glazes will leach toxins into food, and over the years a new generation of potters are not aware of these hazards. Be especially aware of low firing glazes that runs easily during firing, these are almost certain to contain lead and should not be used on domestic wares. Metallic glazes are often not food safe either.
 
Water is used in large quantities by potters, Disposing of waste water is often inconsiderate and it
just get dumped down the drain. Find a suitable material that will aid in settling the solids . The clear
water can then be decanted and used for watering your garden or flushing your toilet while the solid residue can be dried on plaster of paris or unusable bisque containers and disposed of in a suitable manner.
 
Raw materials always come in plastic bags or containers, which should be reused or recycled.
 

Cracked and broken pots once glaze fired can be donated to charity organisations that train handicapped or unemployed people to do mosaics. Cracked bisque ware can be used to aid drainage in container planting.
 
Electric firing is most convenient for potters and definitely cleaner burning than fossil fuels, but we need to relook our medium. A worldwide trend is to work in the mid-fire range rather than traditional high fired stoneware. A lot of industries have developed clay bodies that vitrify at lower temperatures, but studio potters are often unaware of these developments. There are some spectacular glazes available for lower temperatures, and a lot of colours, that would normally fire away at the higher temperatures, can now assure us of a brighter palette of glazes. We are still very ignorant about this in South Africa, but hopefully we will eventually see the benefit of it. We will conserve a lot of energy by firing at a lower temperature, and we could reinvent our work. If you are doing reduction firing or live in rural areas where you don’t have access to suitable electricity, consider using biofeuls to fire your kilns. It is a byproduct made from recycled cooking oil and is much cleaner burning and more sustainable than fossil fuels.
 
It would also not harm to include a green glaze in our palette, if we can not make our craft more environmentally friendly, we can at least remind ourselves to do our bit to reduce our carbon footprint.

Saturday, April 9, 2011

Learning from my Mistakes

Every great artist will admit that somewhere in their search for perfection they did make mistakes. The secret is not to dwell on it, but to learn and conquer.


During a recent project teaching people skills, I decided to develop a new clay body that will simplify the process. I wanted something that can be once fired, with colour included in the body and that would eliminate the glaze process, but still give the necessary sheen. I tried researching Soft Paste Porcelain, but could not track down much information, let alone any recipes. 

The next option I thought about was Egyptian paste. Looking at the drawbacks of making, handling and firing, I quickly dismissed the idea. Working with unskilled people with not a very high level of education, the attempt would have been too frustrating for me and them to turn it into a viable option.

The next thing I came across was something used in the 19th century to simulate marble, mostly used for figurines. I came across a recipe in an old book I found at a flea market many years ago, and decided to give it a try.

Working with the first test batch was very interesting. Although the body was very short, it had great green strength, which was definitely a plus point. I need to add something to increase the plasticity. During the firing process it dawned on me that with the high amount of fluxes, the temperature of 1150*C would be too high. The photograph at the top is the result, everything melted down and bloated totally. I am doing more test firings at lower temperatures, but will also experiment with other fluxes to come up with the perfect solution.

The next mistake I encountered was using platinum luster on an unglazed surface fired to a high temperature. What I envisaged as a bright matt silver colour, turned out to be a rather muted grey. Although not totally wasted,  I will not go this route again. The colour would be much better obtained from slips and engobes, as the price of the luster is too expensive to make it commercially viable.

So its back to the drawing board for me, even the smallest mundane pieces can stimulate your creativity, and hopefully great things will come from this