Monday 17 February 2014

Continuum                                    

Something is wrong with the kiln again, and I’m waiting for the electrician as we speak. The glaze tests fired OK, and I loaded the next batch for the glaze firing; and sometime during the night the kiln stopped working. Very very disappointing. I hope the kiln can be repaired...and soon.

In the mean time, I am making... I need to make 180 – 6(for the base) triangles. It is kind of nice to be in the making routine. When I walk into the studio, I know exactly what I’m meant to be doing. ...and I just make. There are days when mind likes to wander while the hands are busy, but then there are days when it gets inpatient and bored and it wants to be doing something else. On those days I listen to audio lectures. At the moment, highly appropriate: “Philosophy, religion and the meaning of life”.

I have also done a bit of research on Buckminster Fuller (architect and philosopher who popularized geodesic spheres) and found series of lectures recorded live: “Buckminster Fuller – Everything I know”. They are on the waiting list to be listened to next.
But I digress....

I need to make only 27 more triangles + spares. Studio is becoming really cluttered with shapes in various stages of making, drying and waiting for glazing and firing.
Bread crates are really handy way to store ( and transport) lots of work in a condensed space:

Electrician was here, found a loose wire (!!!) and the kiln is ON again. I really hope I get more then one firing out of it before something goes wrong again. I feel like I'm a month behind already.

Problem with not being able to fire work as it is ready is in the broken feed-back loop. Every step of the process has different issues and requires a degree of problem solving. If I'm not able to see the results, I can't change/improve process of making. 
For example, I have discovered that the two types of clay I am using ( hand-building & porcelain) have so different shrinkage rate that the little "planktons" (picture below)  I was putting on the underside of triangles fell of the triangles in the glaze firing.  ( Yes of course. porcelain shrinks so much more). 

So I stopped making them and it considerably reduced the time needed for each triangle. (But I only found that out after I made 80 or so....).

And now to wait for the first full batch to finish glaze firing. I can fit 26-27 triangles in the kiln, and if it all goes well will be able to see results in 2 days.

Sunday 9 February 2014

Glaze choices                                    


Kiln was fixed on Friday. One of the wires got pinched between the kiln wall and casing ( while putting a new metal on the side wall) , so wire insulation melted and short circuited. Took a while to find the problem, but once found it was easily fixed. 
So here are the glaze/surface tests:
porcelain slip, no glaze
If I choose this I can once fire as there is no glaze added at all.
thin clear glaze
Very subtle shine, slightly wet or slimy look.
crawl glaze
This one is intriguing. Cool white.
crater glaze
Creamy, off-white and mat.
thin copper wash
Another subtle effect, but with "aged" patina.

Now I have to make a decision....All of the tests are satisfactory as textures are visible, and colour is in the "white" range.
I'm tossing between crater and crawl. ( those two together were meant to give me bubbly, frothy glaze like on the Gateway arch). 
Crater gives me weathered look - I imagine object pitted by weathering, bleached by the sun and slowly decaying. A coral bone found on the beach.
Crawl is much whiter, intriguing and implies a living organism. I almost expect it to start moving like a lizard. 
The challenge is in trying to visualize a 1.5 meters large object in each glaze and deciding which glaze is most suitable. Once choice is made there is no going back. 

I am lingering with the choices and savoring the possibilities for a while. 
Both are equally valid....
What do you think?


Tuesday 4 February 2014

First disappointments                                    

I have just opened a kiln after a first glaze firing. It was a test for the kiln as well as the glazes. Firing went ok and the kiln has reached the temperature (1210oC) without any problems, but when I opened it, glaze didn’t look the way I expected it to.

I don’t mind the crawl surface, but it obscures all textures underneath.
Not what I wanted. I have spent so much time creating those textures, I don't want to lose them.
This is what I expected, as I used the same combination of glazes as on the Gateway arch:


Why is it happening? Is it due to the change of raw materials? (Very likely as I witnessed problems with other high feldspar glazes)  Did I make a mistake when mixing? (Not likely as I bought just enough raw materials for two glazes, and had no unexplained leftovers)
So what else can I do? I can’t quite picture the sphere in any other glaze. First reaction is to test whatever is immediately available in the studio: test glazes separately, test clear glaze and very thin washed out application of dry green glaze, just in the crevices. I also want to see what it looks like without the glaze. 
So I used broken bits, applied glazes and put them back in the kiln. Restarted it......and instead of a click that announces heating has begun, there are sparks and silence. Controller looks dead.

Silence.

Disbelief.

Studio still has working lights. Press a few buttons on a controller – no response. Fuse has short circuited. And that is the limit of what I can do. Except call kiln electrician.

What was that I said about patience?
Bisque Firing                                                                 

While the whole batch of triangles is drying, I’m (with husbands’ help) resurrecting an old kiln. It looks great from the inside, but the outside is so rusty that the box with wiring has nothing to hold on. The whole thing is literally held by duct tape. I am also waiting for the new controller to arrive.
Patience.
It looks almost new now:



Old kilns never die. Wiring gets replaced quite regularly, inner brick work sometimes, outside gets a new sheet of metal when the previous one rusts out (like in this case) .....but in its hart it is the same kiln.

Getting ready for first bisque firing 


·      Bisque firing is the first firing of clay object, to a temperature lower than vitrifying temperature of clay. It changes it from clay object to ceramic object – which means that it won’t dissolve in water, and it is much stronger than when just dry. Main reason for bisque firing is to make the object sturdier, so that it doesn't break while glazing. Or dissolve in bucket of glaze, or under a tap when you make a mistake or three.

I bisque fire to 1000oC and estimate that the firing will take about 14 hours. I don’t know how long it will take for the kiln to cool down enough to open it. Every kiln is different, and I’m just getting acquainted with this one.