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!