Pottery Sale – Open Studio Weekend

Dear Friends, We will be opening our pottery on the weekend of 13th and 14th of November. We are informed that on the 1st of November, the state will be opening up to allow people from the Greater Sydney Region to travel to the regions like ours in the Southern Highlands. We have joined the Open Studio Weekend organised by the Australian Ceramics Assn. and accordingly, we will be open from 10 am to 4.00 pm on both Saturday 13th Nov. and Sunday 14th Nov.
We are looking forward to seeing our friends again after such a long time in lock down.

We must remind you all that we will be observing strict Government COVID safe protocols.

Please don’t come unless you are double immunised, and have a vaccine certificate to show us. 

We will need to see your vaccination certificate before you can come in and there will be a strict 4 Sq. M. rule applied. That’s 7 people max. in the gallery. Although I can’t imagine that we will get more than 7 people all day, never mind all at one time 🙂
We will have all the doors and windows open for good ventilation and to keep the CO2 levels down to around 450 ppm. As this is considered good practice to minimise the chances of infection.
We won’t have a lot of work fired and for sale by that time, as we have only now just had our first stoneware reduction glaze firing full of glaze tests. I have been very busy working on the 3 local igneous rocks that I could collect within 5 km of our home here, or near the supermarket and Post Office on our once a week shopping excursion. That has limited my choices, but it’s a challenge to make the best I can out of what I have available in my immediate vicinity.


Its shaping up to look like we can make a tenmoku and tea dust glazes from the Hill Top basalt found in the next village. A green celadon from some washed felspathic gutter sand, A pale blue celadon, a yellow matt glaze, Blue/yellow mottled glaze, also made from the local ‘Living Waters’ Basalt intrusion, and a pink matt glaze made from the sericite porcelain body. As well as something resembling a pink/orange shino style of glaze made from the Balmoral dirty felspathic igneous stone. Nothing special, but a workable mix to get us started.
As long as you are double vaxed, We’d love to see you here at some stage, once we are all allowed to travel inter-regionally. Even if there is only a small selection of our our work on the shelves, we welcome you to call in and see the new shed. I’ll be pleased to give you a tour of the Workshop, Pottery studio and Gallery, as well as the raw material processing facilities that we are in the midst of developing – for those so inclined.

We will probably also be open from then on, each weekend, through until Xmas, but please ring beforehand, just to make sure that we are in and open, and not out doing shopping.

Ball mills

Janine made up our first bucket of glaze. She mixed up a 5 kg bucket of Leach’s Cone 8 glaze. We have used this glaze all our life. It is the reliable go-to glaze for testing all our clay bodies. A basic and reliable, no frills glaze that fits right in the middle of the spectrum. A great way to compare the various different clay bodies glaze fit characteristics in our first few firings, which will be nearly all tests.

It can also be an extremely beautiful glaze, a pearly, creamy white, surface. But this is only really true if it is fired just to cone 8 only and not higher. We also ball mill the glaze batch for a little while to get all the particles well mixed. Not too long, otherwise the already finely milled felspar granules will start to break down, releasing its alkalis into solution. Felspar does not have a chemically robust structure, so care is advised when ball milling rocks for glazing. To avoid this damage, I usually ball mill my stones dry after putting them through the rock crushers. I can then store the powder for use in making clay body or glazes, weighing them out accurately dry before wetting them down. The alkali is less likely to be released during dry milling.

I’m not trained or qualified in any way to do with mineral processing, but I have worked with locally found stones for my glazes for the past 47 years. Everything that I have learnt is self taught. I built my first ball mill in 1974. The first year after I graduated and I have built a few more since then. I will probably make another one in the coming years, when time permits. I have always kept a ball mill log to track my ball mill usage. I kept a record of what was milled, for how long and how much was in the mill, wet or dry milling and the date that I milled it, as well as any recipe involved. I lost that log book and all my other glaze recipe books etc. in the fire. Just as I did in the first and 2nd fires. I had two copies of my glaze recipe books, one in each building, but they both burnt down! I can remember that my most recent milling log, kept since 1984, I had clicked up over more than 1,000 hours of milling since then. but the exact number escapes me now. Somewhere around 1050 hours? With an average milling time of 2 to 3 hours, This is about 500 uses of that last mill. Thats a lot of hours of loading, unloading and washing out.

My friends have sourced some 2nd hand ball milling machines for me. Len Smith is always on the digital lookout for me for bits of equipment. He is so fantastically resourceful! He told me about a deceased estate of a potter. I turned up (before lock-down) and was lucky to buy what appears to be a locally made copy of a Shimpo ball mill roller and two 1 gallon, Chinese made porcelain jars. One was broken on the shoulder near the locking stud and the other has a brittle, seized rubber ring seal. Was able to prize the stuck lid off with a chisel. They both need some work. But I was lucky to get them. I made a new silicon rubber seal for the seized and a flat rubber washer type of seal for the other.

I vaselined the ground porcelain jar rim, then extruded a thick silicone rubber ring around the lid and placed it on the jar overnight to set.

This has created a new, soft and springy rubber seal that will keep it going for another 30 years.

My friend Simon Bowley, just gave me his 3rd hand Shimpo mill roller and a beautiful 15 litre Chinese jar. It has the brass wing nut and brass washers missing to secure the lid. This gadget was stored in an old shed for some years, and I’m not too sure if it has ever been used very much. As it still had the paper label from the supplier (Walkers) glued to the outside of the jar. This started to wear off as soon as I used it.

I made a couple of brass washers from the ‘hole’ pieces that I cut from the pottery sink splash-back to get the water pipes into the shed.

I hadn’t thrown them out, as I thought that they might just turn out to be useful some day. A good piece of thick brass like that, 6mm thick is too good to throw away! They came out of the hole saw pretty rough, but I was able to file them down to a smoother finish and drill out the centre hole to a clearance on 3/8″ BSW thread and they work a treat. Not many potters have the luxury of solid 6mm brass washers on their mill jar.

Len also located a very small ball mill unit in Melbourne that wasn’t being used and was able to be donated to me as a bush fire victim. It looked as though it had hardly ever seen the light of day. It came with 2 beautiful Daulton porcelain jars of about I gallon, or 4 litres, and a plastic bucket of small milling media to suit. The jars had some remnant brown dust in them, but looked as though they hadn’t been used very much.

When I tested the small mill roller with one of its Daulton jars loaded with balls and water to clean the mill. I found that the motor overheated and stopped after 25 mins. I can see why this machine wasn’t used very much. It doesn’t work! 30 mins is only long enough to do a bit of blunging, but a couple litres isn’t enough to achieve much. I will need to change the motor for a larger/stronger one. These Daulton jars will fit on the smaller end of Simons mill roller, so I can use them in this way.

My friend Tony Flynn gave me his shimpo potters wheel a few months ago, He also gave me a tiny 1 litre porcelain jar. This could be useful for milling pigments. I tried it on the RMIT roller the next day and it was small enough and light enough not to over heat the motor. It got too hot to touch, but didn’t trip the overload switch. so this will be a useful combination for small batches of pigment.

So now I have a 3 different jar roller mechanisms and by mixing and matching the different jars, I can use the Daulton jars on Simons roller, Tony’s jar on the small roller, Simons big jar on his roller and one of the smaller Chinese jars on the deceased estate roller.

Most of the jars needed new rubber seals. I had already been to the tyre business in Bowral and asked for a punctured inner tube from their rubbish bin, so I was prepared.

All the jars needed to be washed out and cleaned, then filling with balls and water and run for an hour or so the get the surface of the balls and mill all clean and fresh to start work. After milling like this the water turns cloudy, so the balls are rinsed in 2 buckets of fresh water, then placed in a plastic garden sieve to drain and dry out.

The volume of all these small jars added together just about equals the one bigger 25 litre jar that i used to own. The big difference is that to load all 5 seperate jars, run them on 3 different machines and then clean them is a lot of extra time and labour. But at least I can get some stones milled and local rock glazes made to get us going.

I stopped off at a few local sites on the way to the supermarket a few days ago. So I have a few bags of stones to work on. The next step will be to get the rock crushers going. The roller mill is still in pieces and needs some TLC

Kilns

I have now installed the double walled, stainless steel flue on my newly acquired 2nd hand kiln that I built and sold 26 years ago and have now bought back. I was able to buy the flue system parts, even during lock down, as I still have my old account with the company that makes the parts.

I had told the company that I was closing the account back in 2019, as I had arranged to sell the kiln company to my friend Andy. I even took Andy to meet the owners of all the companies that I did business with, and introduced him as the new owner. Regrettably, the fire burnt us out just 2 weeks before the sale was to be completed. So we had nothing to sell.

I rang the company this year and told them the sad tale and asked if I could re-establish the account , but with a new name – Steve Harrison. They agreed and the parts were sent by courier, no new paper work. They trusted me. After all, we had been doing business together for close to 40 years. I have re-activated all of my former accounts now to buy parts to re-build. In every case they agreed to give me my account back with a change of name to my name with no paper work involved. They all know me well enough. Trust is a beautiful thing. I appreciate it. But after more than 40 years of trading with them, I sort of expect it. After all, my account number with one supplier is 001 . Their first customer to open an account!

The new rule will be; No step ladder work after 70! I just need to get this done.

To comply with the Australian Standards for a kiln located indoors. I also had to make a couple of air vents. One at floor level and another at ceiling height to get good ventilation into the room.

The floor level vent is a wide and low format, louvered, and is screened with 16 gauge stainless steel mesh inside and out.

The upper level vent is of the same area, but this one is square. Louvered on the out side and meshed inside and out with the same 16 gauge stainless steel mesh.

It’s always a challenge to work on an extension ladder up at 5 metres these days, but no one else is going to do it. I was a bit concerned about installing it, and put it off for a few weeks, but due to the Lock-down, I can’t really get someone in to do it. Having left it for some time, waiting for the work fairy to turn up and do it for me. But yet another no-show. Maybe the work fairy is restricted by lock down too? So I finally got up the gumption and did it myself.

I had intended to install a large stainless steel hood over the electric kilns end of the kiln room, but due to lock down, I can’t get my hands on any stainless steel sheets, as there are no commercial stainless wholesalers within 5 kms of Balmoral Village.

Kilns fired on different fuels can’t share the same venting flue system, so LPG , Natural gas and wood, can’t co-habit, nor can you flue electric and fuel kilns together.

We have been gifted a small top loader electric kiln by Rohde. Thank you Rohde! The gift was organised by my friend Len Smith. Thank you Len!

As I can’t build a large flue canopy for the electric kiln at the moment. I have bodged up a temporary extraction fan in the window next to the kiln. It will do until I can build a proper one.

I made it so that it can be installed and removed easily and also used in the next window later on as a dust extractor when I’m making up glazes.

I made these two wooden blocks with rebates on both side, plus top and bottom, so that they can lock into the window frame and allow a sheet of plywood with the fan mounted in it to slide in and be held securely. While still being able to be removed easily. I even made them using wood that we grew, milled and dressed our selves.

We have done one test firing to dry the kiln out and establish the protective oxide layer on the elements. The kiln has a small tube fitting that allows the fumes from the kiln to be directed out of the room through ducting. (not supplied.) I have directed the vent fumes out the window through the fan. The vent is only 25mm dia. so I have used 90 mm dia. pipe to vent it out through the fan. This allows a massive excess of cold air from the room to mix with the vent fumes to cool them. allowing the use of plastic pipe. I’d prefer to use a gal steel pipe bend, but I don’t happen to have one. Maybe later.

To finish off everything in the kiln room, we have the LP gas Plumber coming this week to certify the gas line installation. If all that goes ahead, then All we have left to do is make up some test glazes and do a test firing full of glaze and body tests. Slow but positive progress.

Name stamps and a new stool

I have now made 2 sizes of name stamps. Small ones for smaller domestic wares, and a larger pair for bigger pieces. I do these small jobs before and after work in the mornings or afternoons. We have bee throwing now for parts of the last 3 days. Not all day, as there are still so many other jobs that need our attention. Like planting peas, beans and Kohlrabi in the vegetable garden. Planting out 3 potted peach trees that were rescued from the fire and spent the last year and a half in large plastic pots.  It’s almost spring and I need to get them in the ground before they burst their buds.

I also made a 550 mm high 3 legged stool, custom made to suit me for throwing on the new shimpo wheel. I fashioned it out of some fire wood set aside for firing the kiln.

We are slowly filling the bench tops with more pots.

Today, in the middle of the day, we were both heads down at our wheels opposite each other throwing in silence, listening to a CD. When the music stopped, neither of us got up to change the CD. We were immersed in our work. We worked on for some time in complete silence. These new wheels make no noise at all. Our meditations broken only by the sound of a lump of clay being occasionally slapped down onto the wheelhead. The 4 large windows were open and it was a warm, balmy day. I slowly became aware of the noise of bird song outside, the warbling of magpies and then the sounds of chickens walking past the window gently clucking to each other. In the distance I became aware of the faint sound of the Willie Wagtails chat, chat, chatting to each other as they do their aerial gymnastics chasing the invisible gnats and insects in the sky. There are also half a dozen swallows diving and swooping. They even swoop around inside the car port. Stopping to rest on the beams. Janine suggests that they are looking for nesting sites. 2 even flew in through the pottery window and then got stuck inside, not being able to find their way out again, always flying up to the clerestory skylights and banging into the poly carbonate with a repeated ‘thung’ sound. One eventually flew out through the open door. but the other had to spend the night inside. It flew out as soon as we opened up in the morning.

It’s uplifting to see a few birds establishing them selves in this garden again.

It was a moment of precious rural idyl. I realise just how incredibly lucky we are to live here like this. There may be lock down everywhere around us, but we are happy ensconced here in our own little creative world. There is food in the garden and eggs in the laying box. We want for nothing. (except maybe a pug mill)

I spent a bit of time making another smaller set of initial stamps, for when I start to make smaller domestic items like cups.

My next part time, after work, job will be to get the kilns firing. We have both a very small electic kiln and a gas kiln that I’m working on bit by bit. We are almost there. They just need some finer details sorted out. If all goes well we will have a load of dry pots ready for a bisque firing in the electric kiln and then followed by a glaze firing in the gas kiln.

Building a wood fired kiln will have to wait till summer, after the Open Studios Weekends – if they happen? which is starting to look unlikely at this stage.


But before that can happen, I need to make a massive number of glaze tests for that first firing. We have to test a lot of materials. some old bags of uncertain origin that have been storred for years in the part of the barn that didn’t burn, plus others that we have inherited and some that we bought from John Edye when he retired.
It was my intension to go out and collect a load of stones from around the shire to make my glazes. But that can’t happen now until lock down is lifted, as there is only one stone within 5 kms of here, and its rather dull, being a basalt. A 5 km limit really restricts my glaze choices to wood ash and basalt.
It’ll all happen in good time – sometime. I’m working on it. At least these sorts of jobs are ceramic related and a change from building work.

Nothing is ever finished, Nothing is perfect and nothing lasts for ever. 

First Day on the Wheel

We are finally back at work.We have finally got off our lazy bottoms and are back at work on the wheel – albeit only after a long morning pause while we made cutting wires and I carved us each a name stamp.


I started by making a few chucks. These are clay tools used to support pots while they are being trimmed and need to be made first so that they dry out to be stiff enough to support the pots when they are trimmed. I have learnt to keep my chucks damp, wrapped up in plastic and dunked in water after each use, so that they last for several years, kept constantly in a firm but damp state.
Janine started her day by making door knobs for the cupboards in the gallery room.



The batch of clay that we made a month ago is working OK. It’s a little soft, but easy on the wrists because of it. 
I started out using the hand-me-down wooden ‘Leach’ kick wheel, which has always been my favourite style of wheel. but this one is completely worn out. it creaks in all the joints – like me, and needs new bearings, as someone filled the entire tray with water till it over flowed down the inside and poured through the top bearing , filling it with clay dust. I’ve tried twice to get the wheel head off, so that i can replace the bearing, but it stubbornly refuses to budge. I have owned 6 of these wheels in my career, all 2nd hand, and have replace bearings in some of them. I have found that there have been 3 different methods of attaching the wheel head over time. They appeared to have changed the design to make manufacturing cheaper. The earlier models had  the wheel head screwed on with a large format thread cut onto the shaft and wheel head, the second method involved a ’T’ section fitting with a pin through the head and shaft, and the last one was just a simple ‘Morse’ taper that relied on friction.

I’ve tried tapping up and twisting sideways, but this one is very stubborn. The frame was so loose and wobbly that i went down to the ‘spare parts’ pile and found some heavy gauge gal strapping and made a series of diagonal bracings for the creaky wooden frame. That stiffened it up, but it still growls.I gave up on it for the time being, as today was all about throwing some pots. I migrated over to the Shimpo wheel that was a gift from Len Smith. What a wonder this wheel is! completely silent and totally smooth. this is my new wheel of choice now.I need to make a proper stool that is the right height for me. So many jobs still to do!


I have become so used to using beautiful clay straight from the Venco vacuum pug mill, that i had forgotten how long it takes to prepare clay from scratch by spiral kneading. It takes ages to get all the air out! But at least the new timber wedging bench is just the right height.

The Gallery Room is Finished

This last week, we have been working on getting the gallery room finished. This is the last big dirty job to get out of the way. Once this is done we can really start to clean the place up and get ready to make some pots. There is of course loads of other jobs to complete before we can fire anything, but they can wait. They will get done in good time while our first pots are drying.Some of these other jobs will include getting the kilns ready for firing.
However, in the meantime we have cut the huge pine slabs that we milled 20 months ago. I have sawn them into rectangular planks 3 metres long and 750 mm wide and 80mm thick. Not too many people can afford to use timber like this in their gallery. We can’t! It would be completely out of our reach if we had to buy it.


We can only do this because we grew the trees our selves. We got the dead pine trees that were killed by the fire, felled professionally, as they were right up against the house. We then hired a portable saw mill to cut them up into big slabs for bench tops and planks for lining boards. They have been seasoning for the past 18 months.
I had to build an extension bar for my small hand pumped hydraulic crane on the truck. An extension of 3 metres is a bit far, but it worked quite well. I took the first lift very slowly to test that it wouldn’t bend under the load. A few weeks ago, I had a friend come and help me lift and shift these massive slabs onto the ute. But we are now in total COVID 19 lock down statewide, so another solution had to be devised. This way, I can do it all myself.


The huge slabs needed to be cut to have parallel sides and squared off ends, then planed, and sanded a few times with ever decreasing grit sizes of 40#, 60#, 80# and 100#, finally washed to raise the grain. After drying, the rough raised grain texture was again sanded with 80# and then 100# to get a fine finish. There are so many hours of work in getting a massive surface like these slabs from a very rugged chain saw finish, to glassy smooth. I’m not a wood worker, so I don’t have access to any large wood working machinery. All this had to be done with hand held tools. I have to thank my very good friend Len Smith for giving me all his Makita power tools. I need 4 big slabs for the bench tops and 24 planks of 2.4 metres to be dressed like this to make the shelving. It’s taken me over a week.
Once the slabs were finished, I needed to shorten the crane arm to lift them onto the truck to drive them up to the pottery.


I needed to weld up a suitable steel frame to support all this wood.



We’ve ended up with something that resembles a massive kitchen dresser. One on each side of the room, with another huge slab table in the centre. This gives us plenty of storage space in the cupboards and a lot of flat display space. We spent today sweeping, vacuuming and generally cleaning up all the saw dust that ended up coating everything in the place. That is all now done. This was the last really messy job. We can now relax a bit and look forward to making some creative work.


Tomorrow I will start by making some throwing and turning tools. My first job on the wheel will be to make some clay ‘chucks’ to get them stiffened up so that I can turn my pots once I start to make them.

A BIG Day

We are potters again!

We have our hands in clay again – finally. It’s been 19 months and 3 days since the fire.
Today we made our first batch of clay in the new pottery clay making room in the new shed.
I spent part of Friday fabricating a wedging bench, because there would be nowhere to work the new batch of clay coming out of the dough mixer into balls and then blocks, before bagging them up, and moving them to the new clay boxes. So I needed a strong bench.
Every step has been considered and planned, so I have already built the plastic lined clay boxes. Installed the dust extractor. Rebuilt the dough mixer – for the 2nd time after it was burnt in the pottery fire in 1983 and then again in 2019. Making the wedging/clay prep bench was the last step.


I incorporated a marine ply splash back on my bench, so that in the future, I can stack clay on to the bench quite high prior to pugging, without it falling – that is, once we manage to get a pug mill. We have had one gifted to us, but as we are all in lock down. I can’t get it.We are making clay anyway and bagging it up to age in the new clay box, so that when we get a pug mill, we will vacuum pug it and can use it straight away.



All the dry powdered ingredients are accurately weighed out on the scales and placed slowly and carefully into the dough mixer bowl to minimise any flurry of dust rising up out of the bowl. Any dust that does rise disappears up into the bright orange tube of the exhaust fan mechanism and is issued outside.We mixed the powders dry for a few minutes, until all the ingredients were the same colour and all sense of difference was mixed and mingled in together. Then I added the exact, measured amount of water and let it continue to mix for several more minutes, until the batch becomes stiff and starts to ‘ball-up’. 
I’ve learnt that this is the time to add the remaining small amount of water that was withheld from the first pour. This last issue of extra water wets the stiffer ‘balled-up’ ingredients and softens them, I then Iet the mixer run for several more minutes until everything is smooth and plastic.
Amazingly, when I rebuilt the mixer this time around I had to reshape the mixing bowl that had gone out of shape during the fire and had 4 large splits in the metal rim.The bowl had been a little bit pear shaped since the first fire in ’83. So much so that the mixing arm used to bang into the side of the mis-shapen bowl and had scraped all the paint off in one place. Now after this last fire and re-working, I had to clamp it into some sort of semblance of a round shape as I panel beat it back into a useful shape. I had no real idea of how to approach a job like this. I’m not trained in metal work, just entirely self taught. I muddle through most difficult jobs, lurching from crisis to crisis. I manage to succeed by shear graft and persistence, rather than knowledge and skill. So, I was totally amazed that when I came to use the dough mixer this time round,  I discovered that I had indeed managed to make it almost perfectly round again. Well, not perfectly round, it still has a distinct wobble in it, but there is no impact on the wobbly side anymore. There is no wobbly side! Just a general overall wobble. Sort of evenly wobbly! I managed against all the odds to repair it really well. I fully expected it to be worse, not better. I’m no panel beater. So I am really amazed! it’s such a fluke! I am very pleased.



As the clay absorbs the water, it stiffens and balls up.



The hardest part of this ‘dry-mix’ clay making, is having to dig the stiff and sticky plastic clay out of the mixer bowl by hand. In the past, I would unload the clay from each batch into a bathtub next to the mixer. I used to make 8 batches in a row, one after the other, and that would make up a tonne of clay. Enough to fill one clay box. Then I would pug it all through the pug mill with no vacuum to speed up the process (the vacuum process slows down the speed of through put). I stacked all the first pugs of clay in a large pyramid stack and then re-pugged it all again with the vacuum on. This time slicing off all the ends of the previous pug sausages and mixing them all together in one handful into the pug mill hopper. This ensured that any mistakes or slight variations in the 8 different mixes were all averaged out in the final pug sausages.
It used to take me all day to make up, twice pug, then bag and box a tonne of clay. It was a long day and quite hard work overall. I stopped making dry mix clay over a decade ago. For the past ten years or so, I was crushing, grinding, and ball milling all my porcelain stones, to make my porcelain stone ‘clay’. The only time that I used the dough mixer in the past few years, was to make a big batch of wadding for the wood fired kiln.
However, now, on this occasion, we have no pug mill, so it’s all to be done by hand, we work it up by hand into round balls of a couple of kilos, pounding 3 of these together into a block and stacking 3 blocks one on top of the other, before bagging the lot.Each batch we make is 130 kilos and we make 2 batches. It has taken us about an hour and a half for the first batch, but we get better at it, and the second batch only takes one hour to weight out all the ingredients, mix them and unload the batch and bag it all up and place it into the clay box.
I scrape down the mixing bowl between each batch, because I don’t want the thin remnants of clay drying out and going hard between batches and causing lumps later, that will need to be hand wedged to be sorted out.



After we have finished the 2nd batch, I sponge down the mixer and clean the bowl, ready for the next use.



As I made the mix a little wet, to allow the water to fully integrate into the clay as it ages. We left the last 25 kgs out over night to stiffen up a little, so that we can wedge it up tomorrow, wire cutting it and kneading it to remove the air bubbles and get this small amount ready for the wheel. I will need to make a series of clay test to get to know this clay, but also to provide tiles for glaze testing. We aren’t ready for any throwing yet.



We haven’t moved the potters wheels that we have been given and loaned by our friends out of the storage barn yet. There is no room to install them in the studio just now, as it is full of stuff that I am still working on, but the time is getting closer. I still need to finish welding up the benches and table for the centre work station of the studio and a table for the gallery. That will be my next job. Meanwhile, the clay is resting in the clay box and hopefully ageing and improving a little

Ventilation

There are now lots of small jobs to convert our cheap and nasty metal framed farm shed into a functional pottery studio. I had to fill the little gap above the wooden windows, between the metal lintel bar that supports the arch brickwork. This is to stop sparks and vermin getting into the cavity. It also looks better and more ‘finished’, but really, I just had to get it done to complete the building so as to get our final approval and occupancy certificate. 

The next most pressing job was to install OH&S ventilation. A fan in the materials processing rooms to take the dust away from the rock crushers and clay mixers. I never had to worry about forced air ventilation in the past, as the machines were more or less outside in the breezeway between the two pottery buildings. Now that I have them all in the one sealed room. It is essential that I fabricate and install good ventilation.


This metal tube has some 2nd hand/re-cycled 1.5mm stainless steel mesh inserted to stop sparks and insects getting into the building.


And a cheap batroom fan in the other end that will be inside the room.

Connected to a long flexible air hose.


With the exhaust fan embedded in the wall, I can direct the cheap flexible suction vent hose to any machine in the room.

I have no idea how other people might achieve this sort of dust extraction, but this is one cheap alternative solution, and mostly home made.

Clay? What OH&S risk?

Final Inspection and Prepping for Clay Making

We have been working a bit frantically to get all the things on the list completed so that we can get our final inspection, which, if our building passes, will entitle us to get our occupancy certificate. Once we have this, we can legally move in and fill the place up with pottery equipment and start to use the space as it was intended.
The Council Building Inspector called in today in the late afternoon. He gave our work a good scrute and declared that we had completed everything on the list to his satisfaction. He issued us with a carbon copy of his Final Inspection Report and was very complementary about the way that we had transformed a cheap, kit form, tin shed(s) into an interesting building. He commented on our sandstock brickwork and the arch window that visually links the new pottery shed to the Old School building and our use of recycled, old gal iron to enhance the visual amenity of this historic site. I was chuffed.
We celebrate with a dozen oysters off the fresh fish truck that come up from the coast on Wednesday, Thursday and Friday, paired with a couple of cheap sushi trays.


Now we can legally move in. Actually, he didn’t comment on the fact that we already had moved in our kilns, clay mixers, rock crushers and ball mills, the benches, pan break and guillotine, they are all in there and ready for work. I have been using the maintenance shed for a couple of months now to restore my machines and actually make the components to fit out the rest of the building.

One of the first things on my list now, is to make some clay, so that it can ‘age’ for a while, to improve its plasticity, so that when we start to make pots again, the clay will be more workable and respond better on the potters wheel. Having a bit of time to age is very important for freshly made clay, when it is made from powdered materials.

Ageing isn’t so important when clay is made by the wet method involving a slow stiffening back from a liquid mix where the raw material is in the crude natural form straight from the ground.


It might be worth explaining here a little bit about clay. When clay is in its natural crude form, it has a multitude of fine, flat, hexagonal particles, sort of laminated like pages of a book. When the clay is soaked in water and stirred into a watery ‘slip’ or slurry, these flat sheet like crystals are slowly liberated one by one and flake off from the ‘book’. This process takes time. The finer the particles, the more ‘plastic’ and workable the clay can be, realising the best of its potential, but it also takes a long time to get the water in between the various surfaces. 


Stirring the clay and water mix or ’slip’ up into a fine slurry, sieving it to remove any unwanted particles and then letting the slip sit and settle takes time. Sometimes, the clay particles in the slip don’t settle out due to gravity allowing the water to come to the top where it can be decanted off. If the slip doesn’t settle out, then the mixture has to be tested, measured and treated. This involves measuring the pH of the slip. Usually, the clay will need a small addition of an acid to change the pH to very slightly acid.

 
Clay particles have an electrostatic charge on their surface. Clay chemistry is very complex, but suffice to say briefly here that clay particles are a little bit like small magnets. What is needed is to get the positive and negative charges to balance so that they attract each other and not to repel. If they are repelling each other the clay will never settle, but stay suspended and cloudy forever. Once acid treated they can be made to become attractive and will form larger clumps that are affected by gravity, and so settle to the bottom, allowing the water to be forced up where it can be decanted off. This process is called ‘flocculating’ . Think of a mob of sheep forming a flock.


I’ve tried many different ways of flocculating my clay particles. Old red wine that was undrinkable due to cork taint, there isn’t much red wine that I wont drink, but cork taint is one that isn’t drinkable, then I’ve tried cheap commercial vinegar, even cheaper imitation vinegar, dilute brick cleaning acid from the hardware, or epsom salts, but my ‘go-to’ dilute acid is the water in our old pottery water tank full of rain water ( carbonic acid) that has been affected by the constant fall of gum tree leaves onto the old pottery iron roof. This caused the roof to rust and created a moderately acidic solution of carbonic and tannic acid. It came out of the tank pale brown, like cold black tea. When I used this water to make slip I didn’t need to add extra acid. I much prefer this natural method of flocculation. It suits my life philosophy of living naturally as possible and treading gently combined with minimal consumption. Once the clay has settled to the bottom and the excess water removed, the thick slurry can be placed out side in the sun and wind to stiffen. 


This wet method using crude clay is a very slow process. So to speed thing up potters use can use dried powdered kaolin and powdered non-plastics like felspar and silica blended together in a set recipe in the dry state and then just enough water is added to bring the mix to the required plastic consistency. This is akin to making a cake. Although fast, this method doesn’t wet all the available fine particles and the clay doesn’t develop its full potential plasticity. Its a compromise like everything else in life. This dry mix method is fast and efficient and with a tiny addition of some extra plasticiser like bentonite, the preemptive addition of some acid to the water and a period of ageing, then a reasonable result can be obtained. That is what I intend to attempt this coming week. 


When life settles down a little and we have more time, I will make the next batch of clay body by the wet method, using my larger ball mill to mix the liquid slip and allow the slip to sit as a liquid in a large plastic drum for some time and then slowly dry the slip out. This is designed to realise the maximum potential plasticity of the clay body, and is what I have been doing for the past decade to get the most out of my porcelain stones. As they are not inherently plastic, they need all the help that they can get. Tragically, In the fire I lost several tonnes of milled porcelain stone body that I had been ageing for up to 10 years for use in my dotage. 


Before I can make this first batch of quick and dirty clay, I want to make a clay storage box to keep it in. Clay ages best somewhere cool, dark and where it will keep damp with a minimal amount of condensation, that means no direct sunlight, so a plastic lined, heavy duty wooden box has worked well for us for the past 35 years. 


Luckily, back in 1983 when we were building our last pottery shed, after our 2nd fire, I saw two packing cases on the side of the road placed there outside a factory for the taking. 1200mm x 1200mm x 900mm. Big enough to hold a tonne each. We would fill them and when we had used up the first tonne of clay, we would make another tonne to replace it, and then use the other box full while the freshly made tonne was left to age and improve. We kept up this swap and go method of ageing our clays for many years.
Unless I can find two more suitably sized packing cases on my way to the timber-yard today, I’ll be buying a couple of sheets of ply wood and a big sheet of heavy duty plastic, to make some new clay storage boxes.


I still need to line them with plastic – maybe tomorrow?

Finishing Touches – This week it’s plumbing

There are still a lot of small jobs remaining that we have to complete before we can call the Council Building Inspectors and apply for a final inspection. We need the final inspection to get our Occupancy Certificate, then we can be potters again instead of being stuck in this perpetual builders labourer mode. One of the main jobs on the list was to bring water down form the big new water tanks up near the street in front of the barn down to the pottery.
This sounds simple if you say it quickly, but like all jobs it develops a life of its own. Firstly I needed to dig just over 100 metres of trench to bury the plastic water pipe. The trench has to go down the side of the new shed and around the back, across the back retaining wall, across the courtyard and finally up to the North wall of the pottery studio and into the sink inside. 
I wasn’t going to have a sink in this new pottery. We had lived without one in the old pottery for the past 36 years, just using buckets to bring in water from the water tank outside. This avoided any problems with silting up, or clogging up of the drains. However, it was the building inspector who came to do the site visit who talked me into it. He told me that it was a simple matter of getting an S64 certificate, nothing!
Well it’s something! But once committed, I’m following through. First we needed a seepage trench 600mm x 600mm by 10 metres long, then a grease trap, ’S’ bends etc. It all takes time and money and a lot of effort, but we are almost there with the pottery sink and all that it entails.


We are lucky that have very good friends who have a half share in a trench digging machine, so I asked to borrow it for a day last Saturday. It’s a fantastic gadget. I was able to dig the 100 metres of trench in a little over 2 hours. I hit a lot of flat iron stones that are very common in this soil. They sit horizontally in layers not unlike shingles, so digging through them is quite an effort with a mattock and crow bar. The last time I did it manually to do a short 11 metre trench for some storm water pipe on the barn, it took me most of the day, and I ended up digging a trench 300 mm deep x 300 mm. wide flaring open towards the top as I prised out the multiple pieces of flat stone. I only need to bury 9cm. pipe, but the hole was more like the Suez canal!
So on this occasion the powerful machine makes short work of such matters as flat iron stone. But there is always a down side, and that is such that as the machine loosens and evicts each large flat stone, it jambs the drive mechanism. So I had to put it in reverse to spit the stone out. It does this easily, but in so doing, it spits the stone and all the dirt along with it back into the trench just dug. I proceed onwards and will deal with that later.
I was finished with the machine by lunch time. I spent the rest of the afternoon digging the flat stones and soil out of the trench and cleaning it of rubble and roots.
Sunday was spent laying the pipe work. I decided that if I was going to dig such a big trench, to save time and effort later, I would put 4 different pipes into the trench at this time, so that I can use those other pipes to supply high pressure water from the fire pump to the fire fighting sprinklers on the walls and roof of the new shed. Fitting the sprinklers doesn’t need to be done now in the midst of winter, but laying the pipes now is a good idea.


I put in a 2nd trench to the front of the pottery shed to take the fire fighting sprinkler line to the front of the shed while I was at it. This is all taking more time now and is a bit off putting and seems a bit like a waste of time seeing that I’m in such a rush to get this shed finished and passed, but it will be so much easier later when I get up to that job.
With the trenches filled with the 4 different pipes, it was time to refill the trench and cover the pipes. The chickens love to be busy where ever there is fresh dirt exposed.


While I was involved in the plumbing side of things, taking the sprinkler lines up the walls, attaching them and caping them off. Janine and the chickens back filled the trenches.


The last part of this job is to run the pipe into the studio and install the goose neck mixer and taps. We found this set of old hospital taps in a junk shop 40 years ago and bought them for $40 to use in our house when we were building the kitchen way back then. It turned out that they didn’t fit in the place that we envisioned them to go when the time came, so I put them in storage in the barn wrapped in an old tea towel, and there they sat until now when we remembered them. Luckily for us, they were stored in the part of the barn that didn’t burn down. The barn caught fire, but I was there on hand and was able to fight the fire and stop it from spreading too much, so I managed to save most of the barn. These taps included. 


I gave them an overhaul, I pulled them to bits and replaced all the seals and washers, then lubricated all the working parts, reassembled them and gave them a good clean and polish. They never looked so good. I had an old piece of 6mm thick solid brass plate given to me many years ago. It was an off cut from a big job at an engineering place that closed down. I couldn’t ever really find a use for it that justified cutting it. So it just remained stored in my kiln factory. After the fire, I saw it sticking out from the ashes, all bent and twisted and a little bit melted in one corner. Luckily it was on the floor in a part of the shed that didn’t get too hot, in amongst metal machinery and up against the mud brick wall. 


I spent the best part of a day straightening it out and hammering it flat. Well, as flat as I could get it. I gave the centre part a bit of a polish to show that it really is brass, and left the rest with its fire-scarred patina. It makes a suitably steam punk splash-back for the ancient taps.