Wednesday, November 14, 2018

Breathing Life into the Studio!

Detail of Porcelain Bowl with zinc silicate crystalline glaze.
Studios have their own personality. They grow like a shell around the artist that works in them and become a mirror of the life that is lived in it. 

Years ago, not all that long after I had been an an art student, we spent what would have been the equivalent of two week’s grocery money on a lovely book, “The Artist In His Studio”, by Alexander Liberman. The author had made a pilgrimage to the studios of artists in France that were still alive in the early part of the 20th Century, or had died only recently, and photographed them, and also interviewed the artist themselves if they were still living. 

It is a magnificent book, and some of the photographs really touch me deeply. The photo of Kupka in his 80s standing with arms wide spread in front of an enormous abstract painting that he was working on is one of my favourites. He wears his white painter’s smock and a little close fitting cloth cap, a cigarette is held between the first and second fingers of his left hand. His face is tanned and lined, and there is a lively twinkle in his eyes and a look about him, that is like a bird that has ascended into heavenly places. 

Detail of Fire Works #1. Crystals in sunshine!
My own studio had been getting rather neglected, 3 months had passed with very little going on in it, and it had a sad look. Piles of this and that had collected in areas that would usually be better organised for work, and, there was even an old chair that needed mending that was occupying most of my space where I glaze pots. One day, I dutifully mopped the floor, and tried to find places to file away some of the “stuff” that had found its way there. It made me a angry to see the place like that and to have difficulty making room for things. 

About that time, I got a phone call from someone at our Potter’s Co-op to see if I would like to put 3 pots into the Otago Art Society and Ceramics Association of New Zealand (Otago and Southland Chapter) Joint Exhibition to represent the Co-op. There was also a suggestion that my crystalline glazed work might be the way to go.

In spite of making a resolution to pull back from projects with deadlines, it was very nice to be asked, and I said yes… then started to worry over the next day or two, because I had no new crystalline glazed pots, and the exhibition was very soon. What I did have were a number of porcelain vases that I had made a few months earlier, but had not yet glaze fired.

After a few more days of indecision about what to put in, I began work and as I did, the studio started to look happier! Amazing how much more cheerful a place it can be with the mess of fresh activity, rather than the clutter of neglect!

Detail of "pond" in stemmed bowl, Fire Works #2.

Crystalline glazing is not for the faint hearted, it is technical, and requires a lot of testing of glazes and firings of the kiln to get things right. The glazes tend to work best if kiln elements are new, and the kiln is able to heat up rapidly. As the kiln elements age, the performance of the kiln degrades quite noticeably. This can sometimes be an advantage for ordinary stoneware firings, as they often benefit from a good “soak” time at high temperature, but crystalline glazes definitely suffer. 

So…, before I could fire anything, I had to pull out my old and tired kiln elements and replace the set with new ones. 

Unfortunately, with very little time remaining to actually fire pots, I had to make an educated guess as to what the firing schedule would look like and commit some good pots to the first firing in the hopes that one or two pots might turn out. A number of test firings with pieces that didn’t matter would have been the preferable way to go. 

Taken from the perspective of “the cup half full”, the first firing was almost a success, but I could use nothing from it other than knowledge gained! I had been over cautious about the peak temperature that I fired to, and, as a result, the pots were covered in rafts of crystals with very little contrasting glaze surrounding them, and they were not attractive. Also I had been too heavy handed with cobalt oxide on one example, and it was a most dreary looking thing!

It would have been easy to have given the crystalline stuff up at that point, as there was only just enough time remaining for two more glaze firing attempts at most. I was also struggling with fatigue and definitely not feeling my best! One dreary evening I did find myself browsing a French real estate website, and plotting my escape to somewhere remote in the French countryside, where I could lick my wounds and think of something other than crystalline glaze firing!

Whilst the first glaze firing had been cooling I fired a bisque firing of some other pots that were possible candidates for crystalline glaze, so I was able to replenish my dwindling stock.

For some reason I think of this porcelain vase as "Star of India". It is Fire Works #1. Zinc Silicate crystalline glaze with 1 percent red iron oxide.

I made up more glaze, glazed more pots, and fired again, this time about 10 degrees higher. This firing was very successful, and provided two out of the three pots that I needed for the exhibition. 

Porcelain vase, Fire Works #3, with zinc silicate glaze containing 1 percent red iron oxide.

I made more glaze. I glazed more pots, loaded the kiln, and fired again, with slight modifications to the times and temperatures through the crystal growing phase of the firing to change the shape and character of the crystals. This firing was also successful, and provided pot number three. I unpacked it on the morning of the day that I had to take the work in for the exhibition, so could not have cut things much finer!

Unpacking firing number 3.

As is the case with exhibitions, the organisers like titles and prices to be sent in a couple of weeks before the show so that they can put together a catalogue and do the necessary planning. Because I had no idea what would turn out, or even if I would have to resort to rustling together some wood fired pots that I already had, I had to make up titles and prices that were vague enough to cover all eventualities. 

Stemmed bowl (Fire Works #2). Crystalline glaze inside and semi matte black glaze outside.
November the 5th, Guy Fawkes day was fast approaching, so I named the pots “Fire Works” (3, 2, and 1)! 

Fire Works, 3,2 and 1

Very good to have got the pots done. Quite a battle, both technical, and physical, but I’m very pleased to have arrived at something that I am actually really proud of! The exhibition will be held at the Otago Art Society at the Dunedin Railway Station. The opening is 6pm this Friday 16 November and the exhibition runs until 2nd December.

Here are a couple more crystalline pots that worked out well in the last series of firings. I have them here at our own gallery.

Porcelain Bowl with zinc silicate crystalline glaze and attractive pool in base. Approximately 6.75 x 10.5 inches (170 x 270mm) 

Porcelain vase. Zinc silicate crystalline glaze with copper and iron. Approximately 8.5 inches High by 8 inches wide (215 x 205mm)



Linda Starr said...

oh my word your work just gets better and better and isn't the way when we experiment that good things we never expected seem to happen like magic

Peter said...

Hi Linda,
Lovely to hear from you. It does seem that the best work comes along when we experiment and take a risk or two and throw caution to the winds! I guess that magic is like that! :-)

gz said...

lovely work..looking forward to seeing it properly!

Peter said...

Thanks Gwynneth,
It will be very nice to catch up with you in person soon!

Melissa Rohrer said...

All lovely, and especially enjoy the contrast in the glazes you used for the stemmed bowl!

PP said...

I came here to check on that glaze recipe you suggested, and found this new post - what a lovely thing to read. I'm happy to hear you've found your way back to your studio and even happier to see the results. I'm somewhat in awe of crystalline glazes and I know I shall probably never go down that road (too technical!) but it's put the biggest smile on my face to see yours, which are beautiful. The white ones seem to bloom with great delicacy, and the blue ones have much depth. Ceramics is so demanding of mental and physical resources - having to change your elements before you could start! I know so well how hard it seems when resources are low, and had to laugh (in recognition) when I read you'd been hoping to escape to France. I'm really glad you pulled it off, and that the universe, or the pottery gods, or whoever those bloody fickle things are, rewarded your hard work so well.

Peter said...

Hi Melissa,
Good to hear from you. Thank you for your encouragement, it is much appreciated!

Hi PP,
I was amused by your "in recognition" regards escaping to France. I do sometimes dream of that (or selling up and living on a canal boat) when backed into a corner by a hopeless technical hitch or looming deadline! Mmmm crystalline glazes, well they do work... sometimes! But I don't recommend doing them whilst counting down to an exhibition! Almost fun to play with, and there are one or two crystalline glaze recipes that almost sneak into the "reliable" category. If you ever want to have a go, do let me know and I can send you an "easy" recipe!

srgb said...

They say we work best under pressure, My first reaction was that this wonderful result come from you having some down time, what ever the reason it good to see you are creating again Peter, don't be hard on yourself.
Say Hi to Laura

Peter said...

Good to hear from you Bob,
(Laura says Hi!)
I must say that having a break from potting wasn't all bad! I enjoyed doing some drawing again, and spending more time admiring the garden. Generally slowing down a bit. The pressure of meeting the deadline for the exhibition was quite a mountain to climb, but the "view from the top", as they say, was worth it! Lovely to see some new pots, and I really have an urge again to do more!

Best to You both from us at the Old Post Office!

Anna said...

Hi Peter
Some times it takes a deadline to push us to our best...
Well done on these beautiful results

PP said...

Hello again Peter. Well, I'm heading off to France later this week and I know without a shadow of doubt it'll bring on fantasies of moving there.

Thanks for your offer of an easy crystal recipe. I feel the time is fast approaching!

I wanted to let you know that I tried the recipe you suggested - it's actually a lovely glaze and takes a stain well. It's a bit shinier than I had been looking for, but will be good for some mugs for my daughter. I think i'll have a bash at your amended Janet de Boos, with added rutile and copper carb.

Hope things are good with you.

Peter said...

Hi Anna,
Good to hear from you. Deadlines are a mixed blessing, but they do help get things done!

Peter said...

Hello PP,
France later in the week sounds like fun. Rain here, and more rain..... apparently a brief cessation of it on Friday, then it continues for the full 10 day forecast!

Good you tried the glaze, it is a useful one to have in the cupboard!
The Janet de Boos is definitely worth trying.

Enjoy France!

Best wishes, Peter

PP said...

Hello Peter

I'd love to take you up on your offer of the easy, foolproof crystalline glaze that will work in oxidation, if that's ok? I'm up a cul de sac with my hand building and have decided a break is needed. A few forays into glazes would be a good way to go.

And could I ask whether you know of a recipe for a chun-type glaze that would fire at 1280ish in oxidation? I can find nothing beyond cone 6.

I checked back to see whether you'd written a follow-up on how your pots went at the Otago Art Society exhibition - really well, I hope, because your pots were lovely. I also hope the great push to get them done didn't deplete your energy stores too much. I'm imagining it's getting warmer there, and pushing towards Summer. Here I feel we are standing on the lip of Winter, not yet descended fully but able to see down into its depths. Enjoying the comforts of fires and fallen leaves while madly planting every conceivable bulb as a way of planting a flag in the far shores of Spring! All the very best to you.

Peter said...

Hello PP,

Very nice to hear from you again. I did sell one of the pots at the exhibition and also was awarded a certificate of Merit, which was actually quite touching as things have been quite a struggle for the last 12 or more months and I haven't been able to produce much work over that time. To be honest, I was rather worn out again by the effort of getting the pots glaze fired for the exhibition and haven't quite bounced back as yet, but I did do a few hours over the course of the last week or two and clay is quite therapeutic in its way!

Regards the crystalline glaze recipe, you might like to give this one a try. It is a glaze that appears in "More Glazes for Australian Potters" by Janet DeBoos,
and is number 84 in that book. The glaze is listed as cone 6 - 10, but you will want to fire it at cone 9 - 10 to get it to work as a crystalline glaze.
This glaze has a bit more alumina than most macro crystalline glazes, and that makes it easier to work with, both in the glazing stage, and in the firing.

Potash feldspar 35
Zinc oxide 24
Silica 22
Calcite (whiting) 12
China Clay 5

You can add 1 - 2 parts copper carbonate for green crystals
1 - 2 parts of nickel oxide for lovely dark blue crystals on a tan or amber coloured background
3 - 5 parts titanium dioxide for white crystals on a white background
1 - 3 parts manganese dioxide for mushroom colours
also have a play with cobalt carbonate and red iron oxide or combinations of the above oxides.

It is possible to apply this glaze by pouring, dipping and/or brushing, and it needs to be thick in the top third of the piece, and medium thickness in the lower two thirds. It is just about possible to use regular zinc oxide, but it does make things easier if you have calcined zinc oxide. The high percentage of zinc oxide in this glaze will tend to cause shrinkage cracks in the glaze as it drys on the pot. You may be able to buy calcined zinc oxide, but I make my own by putting some bisque fired earthenware bowls in the kiln that are half full of zinc oxide, then firing to about 800 degrees C. This gets rid of some of the chemically combined water and makes the glaze much easier to apply (but more difficult to sieve!!).

Crystalline glazes run like mad when at high temperature, so first tests are best done just on the inside of shallow test bowls. Later you will need to go to the bother of making a porcelain ring for each pot you make, and a glaze catching saucer. The ring is stuck on the bottom of the pot with PVA glue and alumina hydrate, and has to be separated from the pot after the firing.

You will need to fire to cone 9 or 10 (use cones), quite quickly if possible, then drop the temperature to 1100 Celsius and hold for several hours for the crystals to grow. 3 hours is a good starting point. Without the hold you will still have some nice crystals with this glaze, but they will be quite small.

What I will try to do over the next few days is to put a post together about crystalline glazing, and I can explain things in a bit more detail there. In the meantime do make up a test batch of this glaze and try it on the inside of a few test bowls, you should get some results even if put in a regular stoneware firing. These glazes tend to work best on a smooth white stoneware, or porcelain body.

I'll give the chun-type glaze some thought.

Best Wishes to you,


PP said...

Hello Peter

Congratulations on your merit award - I can quite see why you got it. And it's good that you sold a pot. I love selling work - you make something, someone likes it, gives you money and takes it away and you're freed to make something else. After a lifetime of selling services, selling clay work seems such a clean transaction.

I hope your energy reserves build steadily back to where they were. And I agree with you that clay is in itself therapeutic. Except when it's being a total pig. And maybe even then.

Thanks so much for the crystalline glaze recipe. I think I'll save it and allocate an afternoon over the Christmas break. I made several of your glazes today - the flecky green/blue, Len Castle underglaze, and the chun. Fingers crossed!

Anonymous said...

Beautiful pots, Peter! And lovely writing to go along with the wonderful photographs. Thanks so very much for sharing!
Cheers, Owen in Oregon

Peter said...

Hi Owen,
Lovely to hear from you all the way from Oregon! :-)
Just having a read of your really great Paul Soldner post. Wonderful that you found the workshop photos, it is such a lovely record of the event and a fine glimpse of the man himself!
Best Wishes,

gz said...

Ah the magic of crystalline glazes! It was good to see your work for real, in the clay as one might say!
I remember Alan Barrett Danes firing a small electric kiln with crystalline glazes..and doing the down firing with a gas poker!!
Funny though..I chose a woodfired pot....
Thinking of you both as the New Year dawns.. wishing us all health, happiness, good art and good firings!! Holding the memories of Wood fired pizzas...

Peter said...

Hi Gwynneth, lovely to hear from you. I was almost certainly writing about you and Vicfor my next blog post when you sent this! Really nice to have met you both and we wish you a really Happy New Year full of fun and good things done together! :-)
P & L xx