Sunday, August 22, 2010

One that Got Away. Green pots, white pots, and testers.

This is a detail of "one that got away". It was a large pot of a different shape that I hoped would be a good one for crystalline glazing.

This is it soon after unloading from the kiln still on its glaze catching saucer and stand. Everything looked like it was OK until a few days later when I went to pick it up and found that the base had separated from the rest of the pot.. Ooooops! A nice clean break right around.

It had actually crossed my mind that this pot might be vulnerable to something like that happening. I had potted this one quite thickly as I had planned on a good pool of glaze inside, and realized that this could be a likely cause of stress. I guess that the walls of the pot air cooled much faster than the base did, and ..., in the end something needed to let go!

In retrospect I should have let this pot cool right down to room temperature in the kiln before unloading it, as this would have kept the temperatures around the pot more even as it cooled.

Anyway, "we live and learn", as they say, and it is much better that a technical failure like that happens here where I can observe it and add it to my knowledge.

Most things in that firing turned out well, I am glad to say. I had 8 or 9 small pots in the kiln with this larger one, and some more glaze tests.

I am still playing with liner glazes, simple glazes that I put inside the pots. I either use a dark one, like the iron rich one in the pot above, or I am tending to use dolomite matte glazes, which give a smooth off white that sometimes looks really good where the crystal glaze has dusted over it. On one pot that I fired recently, the only good part of the glaze was where the crystal glaze overlapped the dark iron glaze inside. It produced a flowing chun-like blue that I want to experiment further with.

The pot above had a new crystal glaze on it that really didn't do what I intended it to do, but I do like what it came up with! The pot has a dense pack of small crystals all over, and is stone-like to touch. To get the large, separate crystals that I intended from the glaze, I am going to either, take it to a higher top temperature, hold it at the top temperature for longer, or add some more flux.

This white glaze really does make me think of wedding dresses decorated with floral designs. It is a glaze I tested a couple of month's ago, and I have started to use on finished work.

Above is a glaze test that has lots of possibilities. I like the cold, almost violet undertone to this white. This is another glaze that has to go up in temperature to do what it really should, but the stony quality of this test really appeals to me, and would be good on something sculptural.

Above are two tests with 3 percent nickel added to different glaze bases. Again, both under fired, but the colours are fascinating.

You will have notice rather a lot of green pots this time around. I hope to build up a little collection of them for an experimental reduction firing or two. I will be trying to turn some of them red by firing them to about 800 degrees Centigrade in a wood fired kiln, then starving them of oxygen until they are below about 500 degrees Centigrade. Don't worry, I won't do it to all of them.... I like the green, but it will be a wonderful thing if I can get some reds happening too!

I have been making some smaller crystalline glazed pots over the last week, anything from about 5 - 7 inches in height. I have an electric kiln load of them to pack and bisque fire tomorrow.


Linda Starr said...

Too bad about that big pot breaking. Beautiful work Peter, you are getting some really big crystals. My favorite is the white on white, especially the second one you have shown. I also like the shape of the pot with the dense pack of smaller crystals just before the white ones - that little opening and rounded off point is wonderful. How big is that pot? I bet it's wonderful to hold. the violet white looks promising.

acte gratuit said...

If you ever want to get rid of any of your "test" pots, feel free to send them my way! :)
I'll even take that broken pot off your hands. A little super glue and it will be (practically) as good as new!
Emily in Japan

Peter said...

Hi Linda,
Thank you for your encouragement, it is a real boost to the morale! The pot with the dense pack of smaller crystals and the tiny opening is only 4 and a half inches wide by 4 high. It is nice to hold, a bit like a river stone in shape and texture.

Hi Emily,
Lovely to hear from you, and thanks for making me smile!! When are you coming to New Zealand?? that broken pot could be waiting for you! I have super glued it and it doesn't look too bad at all :)

Angie said...

Again you have some wonderful pots the new glazed one ...such a different effect. What a shame about the pot that broke ...I loved the shape.Take care xx

Peter said...

Hello Angie,
Lovely to hear from you. It must be time for a morning cup of tea on your side of the world, and here we are having drinking chocolate and getting ready for bed! Just been watching a TV programme that someone recorded for us, it was about the Dunira Estate in Perthshire and the restoration of a part of the garden there. So we have been enjoying seeing a little part of Scotland here in New Zealand!

I'll have another go at making a replacement for the pot that broke, and I'll see if I can overcome the technical problems. It was an interesting shape for crystalline glazes, as it had the height of a vase, but some of the width of a bowl.

Aleonka said...

I am really impresed, Your "frozen fowers colours" are incerdible. Best regards,

Peter said...

Hi Aleonka,
Welcome to my site:) Thank you for your kind comment, it is lovely to hear from you.

Arkansas Patti said...

You do such beautiful work Peter and I love that you super glued the break. Good rescue.
Yours is a constantly learning craft isn't it.

Judy Shreve said...

Peter - you are getting some wonderfully large crystals! I love the white pieces with the brown (temuko?) liner. They do look like wedding gown material.

Hope you post photos of the greens re-fired -- hope you do get some reds!

cookingwithgas said...

The white is just spectacular!
Despite the broken pot it looked like a very successful firing of pots.

Tracey Broome said...

I was never really a fan of crystal glazes until you started posting these. I really like what you are coming up with! Also like that dark brown inside the green, they compliment each other nicely.

Avi said...

Nice work!! NO TI with NI glaze or you get green.

Peter said...

Hi Patti,
Before I took up pottery, I remember talking to a potter who said that he always was excited about going into his studio every day, and I thought how wonderful that was. Whilst I confess to having the odd day when I struggle into my studio, I am pleased to report that most of the time I am very happy to be there, and I think a lot of that is because there are always challenges and discoveries to be made.

Hi Judy,
Nice to hear from you. I was having a debate with myself today about the tenmoko liner. I think it works really well with some things, but not with them all. I am tending to favour a dolomite matte for more open forms, it gives them a bit more light and air somehow. The tenmoko seems best on pots with small openings. I really want to investigate the runny bits where the crystal glaze overlaps the tenmoko, I am sure I can use that combination somewhere! I'll keep you all posted with the reds!

Hi Meredith,
I think that the only "danger" with the white glaze is that, compared to my other crystalline glazes, it seems quite a reliable one so far..., it is tempting to slosh it over everything!

Hi Tracey,
Flashy glazes of any persuasion do scare me a bit so I am naturally a bit cautious around crystalline glazes too. There is a risk of things being all show and no substance.

One interesting test of a good pot would be to give it to a blind person to hold and admire. In this case the glaze wouldn't matter as much as the form of the pot, and the weight and balance of it. Yes, feel and surface would have some importance, but a good form would be the most important thing.

I think that the challenge of a wood fired pot or a crystalline glazed pot is similar. A fantastic firing in a wood fired kiln can make bad pots seem much better than they are, a fantastic crystalline glaze can have a similar effect.

Crystalline glazes are making life more enjoyable for me. Playing with them gives me similar joy to that a child looking at something through a microscope or a telescope for the first time! The inner workings of a glaze and the firing of the kiln has all become more marvelous and miraculous!

Hi Avi,
Lovely to hear from you, thank you for visiting my site. The titanium and nickle thing had me puzzled for a while, I was sent astray by a recipe in the one book that claims to use about 6 percent titanium and 4 percent nickel and get lovely blue crystals on an orange background.... I got "bad cold" green when I tried that! I have been trying nickel in several different base glazes since then, progressively pulling back on the titanium, and I am just getting to the no titanium ones and am starting to see a hint of something other than green starting to happen. Your "NO TI with NI" is a helpful prompt in this direction! Maybe this time I will get some blue crystals from NI!

jim said...

hi peter, lovely pots and too bad about the crack(ed) pot. i've made the same mistake and now force myself to let the kiln go all the way down... well, at least most of the time. i like the one with the small crystals that's a little matte. i know it wasn't what you intended but i'm a sucker for a nice matte.

Peter said...

Hi Jim,
Good to hear from you, and thanks for the encouragement. I rather like the matte too, it isn't dry to the touch, but feels stone-like, and the light does nice things in the glaze.

Out of interest, do you know if you'll be coming to the Clay and Blogs show in NC? It would be fun to be able to say Hi in person!

Armelle said...

Hi Peter,
I am so sorry for you, you should come to France to the course of pottery restoration, and your vase will have a new life.
Love the greens'ones, all of them.
I came back with a lot of clay to fly (de la terre à battre) and I have less time to blog !!!

Best wishes to you, Laura, and the cats

Peter said...

Bonjour Armelle,
Good to hear from you. It would be a very nice adventure to go to France and learn pottery restoration! Soon I will be an experienced international traveler!

I am pleased that you were able to go on the throwing course, and it sounds like you will be very busy with your new clay. What fun!

I am busy trying to get pots made before I go to America. There seem to be lots of jobs to do before I go!!

Best Wishes to you, Laura says "Hello", and the cats send their happy purring!