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.

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?

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 (1210^oC) 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 1000^oC 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. 

Making                                                                                

After several attempts at prototypes, I am finally happy with curves, thickness and the shape of my triangles. It is great to be making in clay again, although it is hard to imagine how the finished object will look. Image in my mind is still pretty vague. And it keeps changing. 

Plaster moulds are ready, and making begins:

extruding coils

pressing coils in the mould.

Notice the clay triangle at the top? It is there to distinguish that corner so I can assemble the sphere correctly. 

smoothing and "knitting" together

strengthening the edges

filling in corners

cutting off excess clay with the cutting wire

leveling edges with metal ruler

making porcelain slip "bubble"

I love doing this!

pressing a nut in the corners

I'm hoping to use this to assemble the triangles together after firings.

adding porcelain bubble

 This is just for visual fun. Bottom of the triangles will be visible through the holes in the sphere, and it can't be glazed. 

marking future cutting line

Those edges will need to be trimmed later, so the triangles will fit together on an angle, forming a sphere.

ready for drying

 As it dries, clay shrinks , making it easy to take out of the mold. However, if I don't take it out of the mould at the right time, clay will shrink too much and form will break, as the shape of the mould will prevent it from contracting.

out of the mould

Clay is still very soft at this stage so it is easily deformed. Drawing on the board will assure the shape is not distorted

drying near the window

 but not in the full sun

applying porcelain slip

fun and very messy bit

dry and ready for bisque firing

Here in Perth, Western Australia, we are in the middle of hot dry summer. With temperatures in 35^o C– 38^oC range for days (we have reached 42^oC couple of weeks ago) clay is drying very fast. Sometimes too fast.

But at least I don’t have to wait for weeks in order for the work to dry for firing.

Yes, clay has to be absolutely dry before it goes in the electric kiln. (gas firing is slightly different, but that is a conversation for some other time). If there is even a little bit of moisture left in the middle of the thickest part of the object, it will quickly turn into the steam in the kiln and explode into rubble. Ceramists and potters have to learn patience and perseverance. I rarely win arguments with clay.

Decisions                                                                                

I have decided that radius of my sphere will be 80cm (diameter 160 cm). I am too cautious to make it any bigger on the first attempt. That way, if I make full sphere it will stand slightly shorter than an average human.

In the past few weeks while the blog was silent, I was busy designing triangles.

 I want the object to be reminiscent of pollens, planktons, molecules and similar “building blocks” in nature (remember the images at the beginning of the blog??) I definitely don’t want it to look mathematical and geometrical. I also don’t want it to look like clay shingles or ceramic tiles mounted on underlining structure. No, the object has to have “biological” qualities...so I have to introduce randomness ...and holes. Holes are interesting... they make you aware of the thickness of the material, inner surfaces and even objects on the other side. They provide visual interest and rhythm.

Unfortunately they also complicate design as inner surfaces need to be visually as thought out as outer ones...and in this case they (holes, that is) eliminate the possibility of having struts structure underneath.

After several attempts I have settled on this shape:

Here is attempt of drawing - imagining what it will look like:

How will I make it?

How will I put it together?

Assembling part first:

Pieces will be made by press moulding in plaster moulds.

As I can't make correct angles in the mould (or I will not be able to get clay out) I have to cut them afterwards.

Drawings on top of the visual diary page ( above) illustrate cutting line.

Should be achievable.

Careful planning at this stage is really important. More problem solving I can do now,I will have less problems later.

Searching                                                                

First let me tell you a bit more about geodesic domes and spheres.

The word geodesic refers to the shortest distance between two points on a curved surface, and it comes from a Greek geo-, earth, + daiesthai, to divide; thus we have "earth dividing" domes.

Simplest geodesic dome and sphere is based on icosahedron. Icosahedrons have 20 equilateral triangle faces that form very roughly a sphere.

They are called Frequency 1 or 1V domes. Frequency of a geodesic dome indicates how many times each side of the base triangle is subdivided. For example: frequency 3 means the base triangle is divided into 3 lengths, thus forming 9 triangles. It is easy to understand when you look at the drawing:

The Higher the frequency (or number of divisions), the closer the shape is to the sphere. It looks less “pixelated”.

 As a compromise between the complexity of construction and visual impact of the form, I choose to make 3V sphere.

3V sphere is formed from 20 hexagons and 12 pentagons (think soccer ball), divided into triangles. (6 triangles for each hexagon, and 5 for pentagons). Here is where things start getting complicated....the length of the edge of the triangle ( a "strut" in dome language)  varies pending on whether it forms a hexagon or pentagon, or connects them.

3V sphere has 3 lengths struts. I called them A, B & C and colour coded them A green, B blue and C red.

Still with me?? There are lots of web based calculators available that will calculate the lengths of struts, radius of the dome or angles, which is GREAT, as I glaze over those mathematical formulas.

The challenge is that I want to make each triangle in clay - which will need certain thickness - so I need to figure out not only the length of the triangle edges, but the angles as well, so that my clay triangles form a sphere rather than a flat surface.

Now that I know the sizes and angles, next step will be to design triangular components I can make in clay and decide on the making techniques. Fun! Fun! Fun!