Monthly Archives: July 2019

Vegan Wood Firing

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It is a beautiful clear, sunny day here today. The air is cold and a little fragrant. I’m not too sure what with, but it is crisp and refreshing. We have been up to Sydney and back for the opening of the wood fired show, at Kerrie Lowe Gallery, where we have our work on show.

This is a small white tenmoku bowl with a lovely soft ash deposit on the fire face, showing grey some carbon inclusion on the body and rim.

A very delicate and beautiful object.

  

These are two of janine’s blossom vases. These two vessels are inspired by Korean ‘Moon’ jars. On this occasion, Janine has incised a sgrafitto, carved band illustrating the phases of the moon, as a way of linking these beautiful pots back to the origin of their inspiration in Korean, where we have spent a bit of time recently doing our research.

These pots were fired in just 4 hours in our small portable wood fired kiln. This little kiln is so environmentally friendly that I call this type of firing ‘Vegan Wood firing!

All the fuel for this kiln is collected from wind falls in our paddocks. Large old eucalypt trees are constantly dropping dead branches. We have to go around collecting these dead branches to keep the ground clear so that we can mow the dead grass. We have to mow, because in summer, high dead grass is a severe fire hazard. So part of out land management plan is to keep the ground around our house clear of fire hazards, as we live in a very bush fire prone area.

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Having picked up all these dead branches, it seems irresponsible not to use them productively. By firing our wood kiln with wind falls, we are not hurting the trees in any way. No tress were harmed in the making of these pots. Hence ‘Vegan Wood Firing’. As we only use what the tree has rejected and finished with. It is also worth noting that some of the carbon that we collected from the atmosphere through the trees that we have grown here over the past 40 or so years is now encased chemically in our pots, making it securely trapped, more or less forever. So we are doing our bit to reduce the carbon load in the atmosphere. Carbon sequestration and removal on a personal scale.

We each do what we can.

The Flasher

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25 or 30 years ago. I can’t remember exactly. I built a new wood fired kiln in the then new, kiln shed. Now half a lifetime later the chimney has had 4 different kilns attached to it and currently has two. One on either side. I don’t want to waste all that potential energy in a good chimney, two kilns using it seems hardly enough!

It takes a lot of bricks and a lot of effort to build a chimney, especially as you get farther from the ground. It involves a lot of climbing up ladders with buckets of mortar and loads of bricks. On that occasion, I had two good friends to help me. Bernd Weise and Jim Black. With such great help, we were able to get it built it in one day. One person making mortar and cleaning there 2nd hand fire bricks, another passing bricks and mortar up and me doing the brick laying.

We eventually reached the roof and had to cut a hole in the corrugated iron for the chimney to pass through. I then had to move up onto the roof, and continue the brick laying bending down from the 30 degree pitched iron roof. Thirty degrees as it turns out, is just about the critical pitch angle where you automatically slide off the roof if the corrugated iron is new and shiny. Fortunately for me, I had used 100 year old and slightly rusty, 3rd hand, iron for my roof that I had been given for free, to just get rid of it, and take it away.

A bargain! But all the sheets were rusted through where they had been overlapped. I just cut off the rusted section, shortened them and cut others in half to make the new roof. 30 years on it’s still working well, but does have a few more newer holes that I continue to silicon up every few years.

What hasn’t lasted so well is the clay mortar that I used to lay the bricks. I usually use a small amount of cement in the mortar mix for the last few courses. But for some reason, I didn’t do that on this chimney, probably because I didn’t have any at the time. So todays job was to take the top 4 courses off the chimney and re-lay them to make them secure again, as the rain had washed out all the mortar over the years.

I also needed to re-make the flashing to keep the water from getting into the shed down the sides of the chimney. The old flashing was made very hastily, from old used and already rusted, galvanised iron. It matched the roofing sheets! Consequently, it had rusted out in places too and also needed to be replaced.

All I have to do in get up there and do it! Easy when you say it fast. As i’m now more than twice as old as I was then and approaching 70. I though that I had better work out a way of doing safely on my own this time. I started by making a table that would sit on top of the ridge capping and roof ridge, so that I could stack all the bricks on-site to save me clambering up and down the roof with just two bricks at a time.

  

  

With the new roof top table made the day before, the un-bricking was done in no time. There was also a side table for buckets of mortar and the necessary tools. So convenient. Just a couple of trips up the roof and I was ready. The bricks soon re-laid up to the point that I needed to make the new flashing. This time I was able to use stainless steel off cuts for the job. This time it should out last me. If it lasts another 30 years it certainly will. I don’t fancy getting up here and flashing in such an exposed place in the future!

I finished off the last couple of courses above the flashing with a cement enhanced mix of water proof mortar. That should do it. I rather like the view from up here as well. You can see so much more from the elevated position. Maybe I should leave the new roof top table  up here and we can have small intimate soiree up here in the future?

Winter Wood Firing Workshops

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We are very busy all this month with our winter wood firing workshops. We run these every winter, and it has become a reliable part of our income. We will be doing 4 firing workshops this month. We are currently half way through the series. 2 down and 2 to go.

So far we have had some of the best workshops that we have ever held. Excellent results keeping the students very happy. AND a zero rate of losses so far. Pulling red hot pots from a kin at 1,000oC can be challenging. The clay has to be of the right kind and the firing just right. Fortunately, we have a stock the very fast firing and fuel efficient small portable wood kilns that we build in our kiln factory, on-site. We have a number of these at our disposal these days. They work remarkably well, they are a joy to work with. We take about an hour to fire them up to top temperature from cold for the first firing. The work is unloaded using metal tongs. All the participants must be wearing flame resistant clothes, such as woollen material and leather boots or shoes to take part. they must also be wearing long leather gloves when working around the kiln. The hot pots are placed in a bed of damp sawdust to reduce cool slowly. This reduced atmosphere within the saw dust bed causes the clay body to be reduced to charcoal black colour that gives the fired work a distinctive contrast look between the shiny coloured glazes and the matt black clay body.

3 to 4 of these little amazingly fuel efficient kilns are sufficient to fire the work of about 10 students, as the kilns cycle through the day. I have built a few different shapes and sizes , so that we have a taller chambered kiln and a wider setting kiln as well as a cubic  chambered kiln, we manage to get through all the different shaped work in the day.

The kilns are reloaded with new work and left to sit in the residual heat of the kiln for 5 to 10 minutes. This allows the barely warm pots a chance to assimilate the residual heat from the kiln structure, before we start to fire the kiln up again. The subsequent firings only take 30 minutes, as the kiln is already hot, usually around 400oC when the recommence stoking. There is usually just a few small embers left in the base of the fire box, just enough to rekindle the flame and get the kiln going again. As the day progresses, the residual heat in the kiln is increased and there are more retained embers in the fire box. It makes for a very intense series of firings and unpacking. As each kiln and its firing crew work at different speeds with different loads of varied ceramic objects, all the firings and unloadings become scattered in to a series of repetitive, rhythmic ins and outs.

The day ends with a period of pot washing and scrubbing to get the work clean and shiny before packing back into their wrappings, stacked back into their vehicles and heading home.

It’s a very busy day for us starting at dawn, wheeling out the kilns in to the open and getting them ready for firing, stacking wood into wheel barrows, setting up pyrometers, preparing kiln shelves and wads, collecting kindling and setting up the outside coffee and tea table with electric jug and urn, etc. Its intense, we are glad to be back inside by dark, with everything packed away safely and all the surrounding ground watered and raked over to make sure that there are no stray embers allowed to start to smoulder. After dinner and again before bed we make our way back down to the firing site to check for any thing that might have managed to evade our watering can.

Driving on Sunshine – Six Month Review

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We have just reached the half year mark in our ownership of our electric car. We chose the plug-in hybrid version of Hyundai’s Ioniq series of new electric vehicles.

We decided on the plug-in model because it allowed us to be able to charge the car from our solar panels and drive almost entirely on sunshine. This is very important to us as we are committed to lowering our carbon foot print where ever we can — without being silly about it, or being forced to live in a cave and only eat cereals and drink water. The life that we live would be recognisable as being more or less ‘normal’ modern, first world, middle class, living by most.
We chose the plug-in version over the full electric model because we only have the one car and we need to be able to drive long distances a times. Like driving up to Sydney and back, or down to Canberra from the Southern Highlands. It’s not that often, but a few times a year. We didn’t want to be constrained by having to stop and charge the car before being able to drive on, or drive home. The cheaper range of electric cars only offer 200 to 230km range at the moment. Not enough to get us to Sydney and back without having to recharge.
The hybrid version of the Hyundai Ioniq allows us to revert to petrol power to extend our cars range and eliminates ‘range anxiety’ completely. When the fuel tank and battery are both full, the car has a range of over 1,100 kms. No anxiety there, it is in fact twice as far as our old, and very fuel efficient, small car could go on a tank full.
So what have we achieved so far after 6 months of driving. We have filled the petrol tank twice and we are still only half way through the 2nd tank full of petrol. Thats $75 worth of petrol in 6 months. We have driven just short of  6,000kms so far. So nearly all of those kilometres have been driven on sunshine. We filled the car with about $50 worth of petrol at the end of Feb and again at the end of April, again with $50 worth of fuel. We are still using that last tank full. It’s just under half full still. All the rest of the driving has been done on sunshine.
This is possible because we installed solar power in 2007, as soon as it became affordable to do so. It wouldn’t be ethical for me to buy an electric car and plug it into a coal-powered power point. That would be useless. It would be swapping from driving on petrol to driving on coal! An appalling thought in these carbon constrained times of climate crisis and global over heating.
The most recent email ‘monthly report’ that I got from my cars dashboard computer into my phone tells me that we have been driving very efficiently on our sunshine.
So we used 1.78 litres of fuel over the month and drove 697 kms, this equals 391.57 kms per litre of petrol. Pretty impressive, if I do say so myself.
Now that we are more used to owning the car, we have found that we can make two trips in one day easily. We can go to Picton and Tahmoor in the morning and then return home for  lunch and then go to Mittagong and Bowral in the afternoon. The car charges easily in the full sunshine of the middle of the day while we have lunch.
Last week we went out to the movies two nights in a row, and were able to re-charge over night in the dark from our stored sunshine in our ’Tesla’ Battery. The battery then re-charged it self in the morning when the sun rose. I didn’t have to do anything to coordinate this.
Sometimes we recharge the car directly from the sunshine in the morning, if we know that we don’t have to drive anywhere until the afternoon. We can go out again in the afternoon and recharge from the battery on our return
So here we are just past the solstice. The sun is at its lowest angle, for the shortest number of hours and we are still making 4700 watts from our solar panels . This is against the maximum of 6,000 watts that are possible in high summer with the sun up at its apogee. Not too bad!
You can see from the screen-shot below what a winters day looks like and how we charged the car from the battery after sunset.
What is important to notice here is that we sold significant energy to the grid (shown in white) as well as running the house (in blue) and charging the car (in green). The yellow is the sunshine collected, you can see some clouds came over from midday/early afternoon, but we still made a small profit.
This will be the last report about the electric car for 6 months. I will write something more after the first 12 months are completed.
The electric car scene is set to change very rapidly in the next few years as more models come onto the market, But I feel that it will be a very longtime before a fully electric car with a 600 km driving range will be available for the under 40,000 price tag. Maybe by the time this car runs out of warranty in 8 years time, then something better will be available and affordable? I look forward to being spoilt for choice. For the mean time, we are very happy with our decision to go driving on sunshine.