Friday, June 5, 2009

Getting to know you!

Pots that have been fired in a wood fired kiln, often retain a signature of that firing. Flames and wood ash will leave their own mark on the pots, that will be quite as unique as our own finger prints. It is fun to spend time with a pot, and to get to know it.

Where the pot is placed in the kiln, is often as important as how it has been glazed.

This little teapot has freckles of wood ash on one side, but not on the other.


The side of the pot that has been freckled by falling wood ash, was more exposed to the flame than the other side. This has made subtle differences to the colour of the glaze as well.

The glaze is a shino glaze and one I like to use in the wood kiln. If I fired the same glaze in my electric kiln, it would come out an unattractive pasty white. A lot of the colour in this shino glaze comes from the iron that is in the stoneware clay that the pot is made of. The iron colouring is drawn into the glaze when the pot is fired in an oxygen starved atmosphere. Where the glaze is thickest it is palest, and where thin, more of the iron percolates through.

The recipe for this glaze is from the New Zealand potter Len Castle, with a slight tweak.

80 Nepheline Syenite
5 Ball Clay
15 China Clay
+ 3 Salt
+ my tweak which is 0.5 yellow ochre.

The yellow ochre does impart a definate golden tone to this glaze, and without it, the glaze tends to be gray and red in my kiln with less lustre and complexity.

I took the camera to Dunedin with me on Tuesday when I went in to look after the Stuart Street Potter's Co-operative gallery for the day. I catch the bus just before sunrise now, and I had a go at trying to record the sun coming up over the estuary at Karitane, and at Blueskin Bay as we went past. My camera is pretty basic, so its tiny lens had problems catching enough light in the early morning, but I quite like the results.




18 comments:

Arkansas Patti said...

Love the freckles. Did not know there was a difference in outcome depending on type of kiln.
Really liked your photo series on the world being born. Good eye Peter.
The Vet said that Mighty did well in surgery and I should get him back tomorrow. Big thanks to you and Laura for caring.

tsbroome said...

Thanks for posting the recipe for the glaze. As I was going through the blog I was thinking "boy, I love that glaze, would like the recipe"! I know what you mean about getting to know a wood fired piece. I had a tea bowl come out of the last firing (it's posted somewhere in my blog) and I carried it around in my car for a month just holding it and looking at it when I stopped at traffic lights. I still love that little cup so much. Funny what we potters find interesting isn't it? Beautiful teapot

Peter said...

Hi Patti, I am so glad that Mighty came through the surgery, and I know it will be a considerable relief for you to have had Mighty get through that part of the process. Glad you liked "the world being born" photos. What a lovely description that is of yours. I'll think of it now when I see the sun coming up.

Hi Tracey, glad the recipe was of interest. I do hope you give it a try sometime and let me know how it works out for you. It is always interesting to see how these things go in someone else's kiln. Do let me know if there are ever any other glazes I use that you would like the recipe for, I don't keep them secret!

I've got little shino pot that I think I will hang onto that came from this firing. It lost a tiny bit of its foot ring, and has probably done me a favour, in that I won't put it up for sale. It uses another type of shino, Malcolm shino, which is a carbon trap shino. In this case there is hardly any carbon, but a terrific lustre instead and lots of iron spotting. The recipe for that one is in John Britt's cone 10 glaze book, and I have found it also with a Google search, but I'm happy to supply it too if you would like.

Linda Starr said...

Hi Peter, that is a beautiful glaze on the teapot. How did the little swirls appear on the side without the iron spotting? Are those brush strokes? I really like them. You know so much about glazes.

I just love that first sunrise, the moody-ness of it - it's like a painting.

Peter said...

Hi Linda, you are right about the swirls, they are brush strokes.

I first applied the glaze to the pot by pouring it into the inside, swirling it round, and pouring it out. Then I dipped the outside in the glaze bucket. When the glaze was just touchable I brushed some of the glaze on the outside as a pattern. (This works quite well with a glaze as high in clay as a shino, but would be hard to do with a clayless glaze.)

One thing I ment to say with the post was that this particular shino will work well over a bisqued pot, because the clay content is mostly china clay. Some shinos with high ball clay content are much better as a raw glaze because of the high shrinkage of the glaze as it dries.

Kitty Shepherd said...

Loads up really quickly in Spain and I dont have a particularly fast connection.
Nice tea pot, the first one I made at college was utterly brilliant - it had no holes between the body and the spout!

jimgottuso said...

nice teapot... like the little speckles and the sunset shots are dreamy too. glad the firing went well

tsbroome said...

Peter I use malcolm's shino a lot. There is a post on my blog somewhere of a mug I made that has malcolm's on it that I really love. The glaze on your teapot is very similar to it

Peter said...

Hi Kitty, welcome to my site, thanks for the information about how fast my site loads, it has been concerning me that some people on dial up might be suffering from an over burden of my photos! I really enjoyed your comment on Linda Star's site about your spectacular rapid firing of the mugs for the Gielgud Theatre. I've just been for a visit to your blog, and I have to say that you would have to be the most stunning looking 269 year old it has been my privilege to behold! Love your work, and would be delighted to put a link to your site off mine if that is OK.

Peter said...

Hi Jim, it was a sunrise, but that's OK, the southern hemisphere efforts at getting the sun to rise could well be mistaken for a northern hemisphere sunset. This round globe thing is terribly confusing. I suppose that if we had a flat earth, than it would make time and space easier, as the sun would go up and down for all of us at the same time (maybe??)! I used to work with someone that believed that the world was flat, and it made for some curious and challenging discussions.

Anyway, nice to hear from you, and I am greatly enjoying visiting your site.

Peter said...

Hi Tracey, I must have a look back at your past posts and see if I can track your Malcolm's Shino mug down. Malcolm's shino had huge variation in it depending where it was in my kiln. It is a very interesting and rewarding glaze. I'll post some photos of some of the different ways it came out for me, probably in the next post I do.

Jewels said...

The various angles you took of the teapot nicely show the golden luster and the subtle glaze strokes that make it such an engaging teapot! I love the glaze results you get from wood firing! It imparts a kind of elemental beauty onto your pots. I wonder how that particular shino glaze would look fired in a gas kiln. I am looking forward to trying it (when I get a gas kiln). Thank you for sharing the recipe!

Approximately how many hours of daylight do you get in the winter in NZ? I like the abstract feeling of the first image of the sunrise. : )

Peter said...

Hi Jewels, I can tell you the exact hours of daylight for today, this is because I have just discovered the delights of http://www44.wolframalpha.com This is a new "computational search engine", it is great fun, and yielded the following results for your question about hours of daylight.

In Auckland, sunrise was 7:29am, sunset was 5:12pm. The duration of daylight was 9 hours and 43 minutes.
In Dunedin, sunrise was 8:15am, and sunset was 5:01pm, the duration of daylight was 8 hours 46 minutes.

wolframalpha can calculate all sorts of insane things and even play musical chords and scales! Why bother to practice music, when wolframalpha can practice it for you!!??

Anyway, I can tell you that that shino will work well in a gas kiln, as a friend of mine fired some pieces for me. The result is different, but still really good, and best with lots of reduction. You could give it a bit of the feeling of wood firing by shaking wood ash over the piece just after glazing it, whilst the glaze is still wet. It doesn't give you the freckling or the luster in quite the way that the "real thing" will, but it does make things less pedestrian.

I "discovered" another potter yesterday through the blog, and have added a link from my site. Try Mudheart Pottery Blog for really elemental shinos and exciting use of local materials. I'm really impressed.

Happy, and terribly relieved, to report really good sales here today, mostly of work from the recent firing. I was really stressed about things last night and didn't get much sleep, so this good day is a load off my mind. All the Best to you, Peter

Pat - Arkansas said...

The sunrise photos are beautiful, tiny lens, or no.

Thanks for the explanation of the variations in color and markings from the wood firing. Your creations are unique... in many ways!

Congratulations on your good sales! I am surprised your work doesn't fly off the shelves; it's all beautiful!!

Jewels said...

Thank you for directing me to Mudheart Pottery Blog – I have added it to my blog list and am looking forward to exploring older posts.

The wolframalpha site looks like fun but it doesn’t load well on my computer (maybe because I am on dial up). Patti said she has been having trouble the last couple of days with her internet also, so I will try it again in a couple of days.

Very glad to hear (though not surprised) that your beautiful pottery is selling well. After all that you have put into every piece of your pottery, it must be very rewarding to see others cherish it.

Peter said...

Thank you Pat and Jewels, nice to hear from you. I find myself very tired tonight. I have been making small bowls on the wheel all day, and did some teaching.

I'll be taking part in a group show later this month in Dunedin (I think it is only 10 days away). I'm contemplating doing a "heroic" firing of the wood fired kiln to get some copper red glazed work to go with the mostly shino glazed pots that I have, but am probably just silly. I thought I could throw lots of small bowls and try to dry them in time to bisque on Monday, and glaze Wednesday... and fire Thursday or Friday. A bit of a crazy schedule though, but thought I'd make an attempt at bowl making today. I got about 35 thrown, but had lots of other failures with attempts collapsing through trying to throw too shallower profile for the thinness of the clay. Rather out of practice as have been away from the wheel since around May 16th, if my blog is to be believed! Might try more tomorrow and then see if I have a worthwhile looking tally.

marystarosta said...

Yikes, you have been BUSY. Love the Bowl that sold on Sunday...wow"Y" and the tea pot with Shino...very nice!

Peter said...

Thanks Mary, Yes....pace of life has been a bit frantic here! A bisque firing underway as I write and other pots drying above the wood stove... What fun!