All my so-called ‘clay’, is actually ground up igneous stones. I crush the very hard ‘granitic’ rocks in the big jaw crusher first to reduce them down to 12mm. gravel size, then through the small jaw crusher to get it down to sand size and finally it goes into the big ball mill for a few hours to reduce it to a very fine slip with water and 3% of Australian white bentonite. It is the only ingredient that I buy in for this home-made, locally sourced, native porcelain body.
After ball milling, I test the pH and adjust it if necessary, it usually needs to be reduced a little, as the ball milling breaks down the structure of some of the felspars and micas in the stone. This releases tiny amounts of alkali into solution in the slip. The effect of this is to constrain the plasticity of the porcelain and inhibit the ageing plasticisation. Once adjusted to the correct level, the slip is stirred and then put through a fine sieve to remove any oversized particles and any foreign matter that has crept in during unloading. Thick slip is very slow to pass through a very fine mesh, so I resort to using a sieve vibrating machine to shake the sieve while the slip pours through. It’s quite amazing just how fast this process becomes with a little vibrational energy to keep the larger particles moving and not sitting and blocking up the fine mesh. ‘Vibro energy’ a really great focussed use for very small amount of electrical power.
Without the rock crushers and ball mills, I couldn’t make this local ‘native’ porcelain. In the past I always used to feel a bit guilty about using electrically powered machinery, as I was brought up in a family where ‘green issues’ were openly discussed, long before the ‘greens’ were invented as a political movement and ‘green’ came into the environmental lexicon. I’m not too sure what my parents actually called their lifestyle back then. Possibly ‘environmentally conscious’? Anyway, I’m happy to be called a ‘Greeny’ now and all that early environmental awareness has stuck with me. Give me the boy till he is 7! Now I am getting used to thinking differently about electricity as we are slowly becoming a fully electrified solar-powered household.
Electricity was always made with coal here in Australia and most of it still is. You have to specifically request to be put on a green power contract, and then pay a premium tariff for the pleasure of not using coal. 25 years ago, you couldn’t buy green power. Everything was coal, coal, coal, so I decided to make an effort to use the absolute minimal amount of electricity and we were very successful. We learnt to run a very lean electrical household. We have a very modest ‘LED’ screen television. A very efficient fridge that runs on 1 kW per day and a front loader washing machine, also very efficient. All in all we average an electricity usage of around 3.5 kWh per day. Very modest. We have chosen not to buy home theatre, a dish washer or air con. We have had solar hot water for the past 30 years, Solar electricity for the past decade and a Tesla battery since the start of the year. To the best of my knowledge, we have completely removed ourselves from the coal economy now.
When we did buy power from the utility, up until last year, it was always a battle to buy ‘clean’ green energy. They just hadn’t thought about it and weren’t prepared for the transition. It was a dinosaur industry. People like us wanted to buy clean energy, but they hadn’t put any plans in place to create any. It was all about business as usual. As the requests grew louder, some clean energy was slowly introduced, such that you could buy just 10% of your electricity as so-called ‘green power’, but it turned out that it was only hydro power from the Snowy Mountains Scheme. This was electricity that was always being generated since the 50’s and sold into the grid as part of the usual mix. But then the bean counters and ‘The Men in Suits’ got involved and thought why don’t we sell Steve Harrison the electricity that he is already buying, but sell it to him at twice the price. If he is silly enough to pay for it! I wasn’t, so I didn’t.
We waited a long time, until the first wind farm was built just South of here. Then there was an offer that you could buy 20% of your power bill as wind energy, so we did, and continued to increase the percentage every year or so as more clean energy was built and made available. I remember that we were early adopters and had to go on a waiting list to get a higher percentage of clean energy. However, the energy company kept sending us supposedly attractive offers to change back to a cheaper dirty black power contract. This just reinforced to me that the market for green power was stronger than that for coal power. Apparently they had too much coal power and couldn’t get rid of it all.
Then there was government intervention to support the coal industry and then privatisation that was supposed to make every thing more efficient and cheaper. And what happened? The price went up about 200% here. A complete failure of market forces and competition.
Today I check in on our power usage on my phone app. I see that we are making about 5kW of solar power, not too bad, seeing that we are just a month off the winter solstice. We are only using a few hundred watts intermittently, that’s the fridge compressor switching on and off. There is a spike at 8am. That’s the toaster and electric jug for breakfast. It’s probably hard to live any kind of normal life and use significantly less power then this on a regular basis.
Back to my clay tests and I pour them out onto the drying bed to stiffen up. Again I’m using solar and wind energy in this very passive way now to remove the excess water from the slip and reduce it to a plastic state. The sun shines for free every day. The wind blows most days, slowly the water is evaporated from the slip and it becomes stiffer and plastic. It’s gentle, it’s energy neutral and it’s free!
I’m very lucky to be able to live this rewarding, creative life in carbon constrained times. We are preparing ourselves for a creative, energy passive future, but it’s funny that trying to live a simple life gets quite complicated at times.