Tuesday, April 22, 2014

Close Up

Easter and Autumn, an interesting pairing. In the North, Easter and Spring conjoin to speak of hope and new life; in the South we could think of stillness, distance even, and a time of cleansing.

Spoonbill. We see a lot of them here at this time of the year.
Not quite sure what happened here, I think a bit of cross species activity took place!

Black Swan. All curves, stillness, and perfection. Standing on boggy ground that has been moulded by countless pairs of webbed feet!
There is a chill in the air that the afternoon sun cannot quite mask. Six or eight weeks from now, there may be ice on the lagoon, and the last of the dry autumn leaves will crunch and snap underfoot. Meanwhile I have been doing my best to make frost patterns in my kiln.. at 1100 C (2012F).

A Plate Seen Closely
Looking closely at ice or crystalline glazes with the help of a magnifying glass can transport you into a really beautiful place. I recently fired this 9.5 inch (240mm) plate and was very pleased with the result. I love the explosive puffs and huffs of the crystals, and the mysterious green-blue depths of the glaze where it has pooled.

Is it a Bowl or a Vase...? Not Sure!
A few months ago I made a little series of deep bowls or vases that had narrow bases and decorative pouring spouts around the rim. I have been holding back before glaze firing them, as I was not too sure what glaze to put over them. At one point I came close to making them white and just being "all about form", but I tried this one with a crystalline glaze on the outside and an oil spot glaze on the inside, and was pleased with the result. This piece is about 7 inches high and 9 inches across (180 x 230mm).

The oil spot glaze that I used on the inside works well on porcelain, much better than it did on my stoneware when I tried it a few years ago. This oil spot glaze has about 8.5 percent red iron oxide in it. At temperatures above 1000 degrees Centigrade (1832 F), iron oxide begins to change to become iron monoxide, and it loses oxygen. The oxygen bubbles out through the glaze, but it does so with some difficulty, as the glaze is a very stiff one. The marks that the bubbles leave in the glaze do not entirely heal over, so a characteristic pattern develops. In some respects the oil spot glaze is the opposite of a crystalline glaze. The oil spot is high in alumina and is very stiff, the crystalline glaze is extremely low in alumina, and ridiculously runny!

 A Bottle
I have been doing more oil drip reduction firing of crystalline glazed pots. This 8.5 inch tall bottle (216mm) gave me quite a surprise when I opened the kiln after the firing, as I had expected a very different result. After its first glaze firing, this bottle had been a pale aqua blue with blue grey crystals. The crystals were a little indistinct, and did not have quite enough tonal contrast with the background. The glaze had some copper, cobalt, and a little manganese in it for colour. I thought that it would be a good idea to do an oil drip reduction firing and see if this would improve the definition of the crystals. I had expected red crystals on a grey or pale pink background, but this is far more interesting. Carbon has been trapped by the crystals, turning some of them black. The heavily reduced copper and cobalt metals that are concentrated in the crystals, gives the copper "glow" that breaks through the carbon.

Some of the other pots that were in the same firing were really too smoky looking and I will re-fire them. I am progressively cutting back on the amount of oil that I drip into the kiln for generating a reduction atmosphere, and the length of time that the oil drip is in action. Currently I am still just a little "heavy handed", but progress is being made!

I must try blogging more often again. It seems to get more difficult when I leave big gaps between posts... 


Teresa Evangeline said...

It's all too easy to forget that you are entering what we are leaving, and not a day too early here. What a long, difficult winter it was.

But, what a gorgeous plate! Just beautiful!

Linda Starr said...

Love the plate and the bowl, nice to see the crystals on a plate; also like the different color inside the vase, it's a nice contrast, love seeing all the birds especially the black swan.

steve said...

I love that oil spot glaze, such a contrast with the blue outside.
they are beautiful

Peter said...

Hi Teresa,
Lovely to hear from you. Yes, your winter seems to have gone on and on and you will be desperate for the sunshine! We had a strangely cloudy summer here, so I have green tomatoes and a garden that is "confused" and still wondering if summer might arrive! Do you think we are now in for a few decades of global cooling??? Now there is a thought!

Hi Linda,
Good to hear from you. I enjoy seeing the black swans too, and keep thinking that I really must try to do some sculpture that is inspired by them. The sight of several of such large birds flying in formation is magnificent.

Peter said...

Hi Steve,
Welcome to my blog. Thank you for your nice comment. I am really pleased to have tried the oil spot glaze with the crystalline. It was one of those "happy accidents" in a way. Mid way through glazing I found I was running short of the dark brown tenmoko glaze that I use inside crystalline pots, and discovered I had a lot of the oil spot glaze left over from some testing, so decided to give it a try!

Pat - Arkansas said...

The bowl/vase is gorgeous, and I love, love, love that bottle. Well done, Peter.
Enjoyed the photos of the birds and water. It continues to be hard for me to wrap my head around the seasonal differences 'down under.' Happy Fall, Peter! :)

Peter said...

Hello Pat,
Good to hear from you, thank you for your enthusiastic encouragement! It is funny how winter and summer, can be happening at the same time at opposite ends of the world! Whilst I watch leaves turn from green to gold, you will be looking forward to, and enjoying, spring flowers in your garden! Kind thoughts from us all, P,L, and NS xx

Armelle Léon said...

Hello Peter,
What a stunning close up of the blue crystals !!! Love the photos of the birds, all beautiful. Maybe I should post more often too :-) Happy Easter, with a little delay, and a Happy Fall, by the way.

Peter said...

Hello Armelle,
Good to hear from you. Yes, I think we both should post more often!!:) I find that it is very easy for life to crowd in, and the blog not to get done. Happy Easter to you too. I guess that you must be home again? We had two French hitch hikers stay the night here a few days ago, when they were unable to get a lift out of our village. I am firing two hand basins in the kiln this morning...
Best Wishes, P, L, & NS

Sue said...

Hi Peter and Laura. I'm in gorgeous Kaikoura, with a view of the mountains from the ranch slider. What an amazing country we live in!
Its fabulous to see the mix of your pots and the wildlife around your area.
Love the beautiful blues and greens of the bowl.

Peter said...

Hi Sue,
Lovely to hear from you. Kaikoura would be wonderful on a fine autumn day, especially if there is a sprinkling of snow on the mountains! I'll be posting some photos of Karitane that I took on Saturday really soon. Amazing what delights we have so close by! P

Sandy miller said...

Hi Peter,
I love coming to your site; beautiful pots, great information on what you are trying out and nature shots.......

thanks! My morning coffee was complete :)

Peter said...

Hi Sandy,
Good to hear from you. Nice to know that reading my blog can enhance the taking of morning coffee!