While my work dries and I wait to pack the bisque, there are a few people and places I need to catch up on. I’m invited to both a lunch and a dinner with the students and staff of the Museum on two different days. I love Korean food, everything comes with chilli, even some sweet things!
After we have finished eating our lunch, it’s time to settle down and help the residents of the Baekto Porcelain Village make a thousand glaze test tiles. Everyone gets involved at different times. Many hands make light work and they are all made in one day.
I’m not really part of the group and I’m not too sure how I can help out in an unobtrusive way, so I decide to do the picking up off the floor of the cut sections and place them within reach of the real workers who know what they are doing. Later, having shown interest and done my time on the floor. I’m promoted to press-moulding the curved sections ready for assembly.
Before leaving the village, I wander up to the kiln shed to check out the kilns and I see 4 pallets of 2nd hand fire bricks, all cleaned and wrapped and one pallet of new firebrick slabs. I quickly calculate that this is about 2,000 bricks and 90 slabs. I’m guessing that these have been purchased for the kiln building workshop that Mr Jung has proposed to me. It may take some time to eventuate, as there doesn’t seem to be a a floor slab or roof for the kiln as yet.
I am scheduled for a meeting with Mr Jung and The Premier of the County of Yanggu, or State President, along with Myeongki Shim, the translator who has worked with me in the past and did the translation of my book, 5 Stones, into Korean. We are scheduled to meet on Friday to discuss the idea of offering a workshop style summer school open to potters to come and take part and learn about the down draft firebox in the process. I can see this taking some time to organise.
It might not be the lack of a slab and roof that hold things up? Political realities being what they are, and money being hard to come by. We’ll have to wait and see.
I’ll need to do some calculations to get the whole thing to work correctly, as all the bricks are solid, hard fire brick, so this will limit what I can achieve with just one simple fire box. I’m also told that they don’t want to use ceramic fibre here for the lightweight firebox stoke-hole door, so there goes the idea of a top loading firebox lid and a throat chamber lid. It is starting to look like I might be building quite a small kiln, as I want to build and demonstrate a simple example of a single firebox, single chamber kiln that can be fired fairly cleanly in one day. Something in total contrast to the week long firings that take place in the traditional 5 chamber kiln that they have here.
The water wheel is working today, as Daewoong the resident wood fire potter, is keen to prepare some porcelain stone by the old method of using the stamp mill to crush the sericite. I’m unsure what he is planning, it could be for glaze instead of body material. Time will tell.
I can see across the valley to the new solar power farm that has recently been installed to generate solar electricity for the village. The admin block here was already covered in Solar PV panels, as is the Museum roof. It is noticeable to me that the new solar farm hasn’t taken any usable flat ground that was already used for farming. They have chosen to use the slope of the hill to get a good azimuth angle to the solar rays and not upset any farmers by taking over fertile, flat, productive land.
There has been a firing going on in the big gas kiln all day. The kiln is used by the residents in the porcelain Village. They can book the kiln individually, or as a group firing. They only have to pay for the gas consumed. As I understand it, the residents get free rent of studio and housing spaces, plus free use of the equipment like kilns, wheels, slab roller and pug mill, etc. They only have to pay for their own food, heating, kiln fuel and any exotic raw materials that they may wish to pursue. It seems like a too-good-to-be-true deal from my point of view, as an outsider from Australia, where the Arts are more or less ignored, or if acknowledged, they are mistrusted and/or miss-understood by the general public, encouraged by the Murdoch press, and any money spent on the Arts is roundly ridiculed by the conservatives. No wonder the facilities here are all full. It seems that the locals think that this is normal and complain about having to pay their own heating bill! I couldn’t get a room in the student accomodation building this time round. Everything is fully utilised, so Mr Jung has kindly offered to allow me to stay in his home with him, 30 minutes away in Yanggu.
When I get to the Museum and Research Centre the next day. The bisque kiln is ready to be packed. My work is all completely dry now. I take it over to the kiln room for packing. There are 2 large electric kilns used for bisque firing on a regular basis. These are used to fire the the part-time students work from the teaching facility.
My work is slotted in where it will fit among the regular student projects. My work isn’t large, so it can be fitted in economically. I nest stack them to conserve space. I start with a 5 high stack, but I am discouraged by the technical assistant/pottery teacher. He seems to indicated that with this clay, its particular dry strength and firing characteristics, it is better to just go 2 high, so I do. The firing goes on over night using a ramp programmer. It’s all very modern and efficient in this regard. However, in contrast to this, they also have a 5 chamber traditional wood fired climbing kiln as well for the wood firing enthusiasts. We took part in a 4 day firing of that wood kiln the last time we were here.
While my pots are cooling down from their bisque firing. Mr Jung arranges our us to go on a geology expedition up into the mountains behind Yanggu. There are some logging tracks that we can use to get us up there quickly. He tells me that because he was born and grew up here in the foot hills of these mountains, he has tramped over most of it through the years. We swap his LPG-hybrid, city sedan, for his parents small 4 wheel drive, and set off. He wants to show me a couple of sites that he thinks might be worth our while investigating.
After a slow and bumpy 45 minute drive over the rough logging tracks, we arrive at the first of what turns out to be 5 sites. This material looks to be a weathered or kaolinised, fine to medium grained acid rock with some small amount of free silica. It’s impossible to say what is in it, but I can hazard a guess that it has some sort of primary clay such as Kaolinite, Halloysite, illite or dickite. It also has the obvious spangles of some free silica that is just visible in the bright sunshine, then there may be some flux minerals such as the felspars or micas, if they haven’t all be weathered down to the clay minerals. The stone is very soft and easily broken up by bashing it together, so I’m certain that it will be low in flux and higher in clay minerals.
The stone is so rotten, that the fragments are just tumbling down out of the hill side. To my naive geological eye, it looks pretty much like a lot of the material that I have collected back home in the Southern Highlands. It may be able to be finely milled to become sufficiently plastic to be throwable. But they already have a marvellous sericite body here that is beyond excellent, white, plastic and translucent. This new stuff won’t compete. I’m thinking that it might be possible to make a glaze out of it, but it looks a bit too weathered, kaolinitic and refractory to make much of a glaze with just limestone as a flux. I’m not sure, I get the feeling that it might need some extra felspar as well, and perhaps a little ash with it as well?
I have no real concrete evidence for this thought, it is just what I have experienced back home in my previous research in Australia. The stones that are hardest to crush usually have the most intact alkali content and melt well. The softer materials that are very crumbly, have usually lost a lot of their alkali during weathering and are more refractory. Where this stone fall on the spectrum i can only guess at this point. I won’t know until I have fired some. However, my guess is that it will fall somewhere smack in the middle. Unmelted on its own, but forming a glaze at the end of the line blend series, requiring the maximum calcium flux.
When we get back the the Museum a few hours later, I set to work making a few tests. I Start with a grid tile test to ascertain the chemical analysis. This is a unique test that I developed during my PhD. I involves producing a series of line blends with specific additions of a set ratio. The resulting grid tile when glaze fired, shows a particular range of melts and colours. By comparing the new material test with my data base of known and chemically analysed test tiles. I can deduce the chemical analysis of the oxides present in the new material to with in a couple of percentage points. It saves having to send the material off to the university chemical lab and pay a lot of money to learn the same thing.
Pretty clever I think, if I do say so myself.
Apparently. I am the only one who thinks so and says so. Everyone here watching me work, have no idea what I’m doing. but they keep an eye on me, just the same.
I also take a risk and follow a hunch and prepare a line blend in a series of 5 simple steps that I think will show some worthwhile result using this material as a body ingredient, based on my research on similar materials that I’ve worked with back at home. I’m guessing that it will be nice in a wood firing, but I’ll never know, as I only have sufficient material crushed and ground to made these few basic tests for the gas firing coming up. There isn’t a wood firing due at the moment.
I used a bisqueted test tile that I have brought with me from Australia in my suitcase to do such a test if necessary. I’m glad that I did, as there is no time to make one now and get it through the next bisque in time. I decide that I will only do the first three line blends on this occasion, as the last line will be too siliceous to tell us much about a stone like this one. Or so I think. I decide to use the remaining material to make the body line blend of 5% increments.
The next day, the bisque firing is unpacked and I start to glaze my work.
I get all my work glazed and fettled and out into the sun to help it dry out by early afternoon. The smaller and lighter of my bowls are quite delicate and thinly potted. So I can only afford to swipe them through the glaze in one second, so as not to saturate them. Otherwise the glaze will start to run off before it dries. I like to glaze all in one motion if I can, but these pots won’t have sufficient glaze on them to develop any depth of colour. So I decide to partially dry them and give them a second dip to create a thicker glaze coating. This carries a risk of causing pin holing and crawling, but I weigh up the options and decide to take the risk.
I could choose to spray on a thicker coat, and that would work better, just as the ancient Chinese did a millennium ago, but I’m not from around here and don’t know if there is a spray gun available. There certainly is a compressor, as I’ve already used this once before to blow the dust of my bisque ware. However, I don’t want to outstay my welcome, by constantly bothering the staff, who are always busy, by asking questions, unless it is absolutely necessary. Of course I am incapable of asking any question directly. I involves the use of the translation app on our phones. It’s a slow process and takes up their time typing out questions and answers with one finger on the tiny virtual key pad.
There is a change in this regard this year. I’m asked to down load a new language app onto my phone. This is a new Korean developed translation app, and every one here is using it. It is specifically built to translate Korean. It handles spoken word input too, which speeds things up. There is a little hick-up here with this. My Australia Post prepaid travel SIM card doesn’t handle data. Only calls and texts. Data packs can be purchased for other countries, but not Korea at this stage. So it turns out that I can only use the ‘Papago’ Korean translation app. when i have WiFi service to log into. That really limits where I can use it.
The standard porcelain glaze that they have developed here looks to be made using some sort of ash, as it has a fine grey cast to it and a infinitely fine dark speckle in the dried surface. It just looks like an ash glaze. I can’t justify that opinion any more than that. The next time My Jung, The Director of the Museum passes by, I have my question already typed out on the phone. “Is this glaze made with ash?”. He responds to me in English, “tree ash?”, I respond “yes, tree ash!”. He indicates to follow him into the next work area. I haven’t spent much time in here at all. I have only just glanced as I passed. I have had no business to be in here. I try not to cause any trouble as a guest. A position that I am very grateful to be in.
Mr Jung takes me to the ash preparation area. There are a series of very large tubs where ash is washed and sieved, then left to settle. In the settling tank, there is a rope suspended in the water. I must look puzzled, as Mr Jung the word in English, “magnet”. He shows me this by lifting it out by its rope and sticking it to the metal floor grating, which he demonstrates, he can now lift up out of the drain, just by the power of the magnetism. The big round magnet must be very powerful. He takes the magnet to the sink and washes it, and to my surprise, it is not big and round at all, but narrow and skinny. It was clustered with irony material stuck to it. I don’t know where all this iron came from, perhaps they burn the organics in a steel furnace?
The cleaned magnet after washing off all the irony ash particles.
Mr Jung then takes me to the glaze store room, where he shows me the working stock of dried ash that they make here. There is ash made from all sorts of plants. Mixed tree ash, Pine ash, chilli plant ash, chrysanthemum ash, ginkgo ash, even calendar flower ash! I’m stunned. So much work! I know what I’m looking at, because we burn plant material to create ash back home and sieve it and dry it. But not on this scale. I guess that it helps if you have a staff of 12 to help you get everything done. The biggest problem that Janine and I face, is that we are trying to do everything ourselves. We are getting older and not surprisingly, we get tired.
I wouldn’t mind a staff of 12 to help get things done. Not too sure how we would pay them though? Actually, just a part time staff of one would be nice.
My glazed and fettled pots are now packed into the glaze kiln. They will be committed to the fire tomorrow in a 12 to 13 hour reduction firing to 1260oC. I’ll have to just sit it out and wait-n-see.