(Team Design) Personal Development: There’s a Place for Everyone
Imagine you’ve spent hours creating the perfect clay vessel.
In the presence of water (which I refer to as “Weft” when speaking in metaphoric terms of topics of spirituality), clay vessel reverts to its original form.
But when fired, the clay takes a one-way journey to become an entirely different material, and cannot return, so to speak.
And so it is with some people.
Clay minerals are composed of aluminum and silicon ions bonded into tiny, thin plates by interconnecting oxygen and “hydroxyl ions” (oxygen bonded to hydrogen).
These plates are tough but flexible, and in moist clay, they adhere to each other. The resulting aggregates give clay the cohesion that makes it plastic.
Anyone who has played with clay knows what this “plasticity” feels like.
But when the clay is dried, most of the water molecules are removed, and the plates hydrogen bond directly to each other, so that the dried clay is rigid but still fragile.
I repeat: rigid, but fragile.
To strengthen the vessel, it must be fired in a kiln.
Clay goes through several physical changes when fired. The first step is the evaporation of water from between the clay particles.
Pots must be completely dry before firing, otherwise the steam escaping could cause them to explode. Initially, the kiln should be heated very slowly to give time for all the water to evaporate.
The next stage is to drive off the water which is chemically combined with the clay. This is known as dehydroxylation and occurs up to 1022°F (550°C).
Once this chemical change has taken place, the process cannot be reversed and the clay cannot be returned to its plastic state.
At 1063°F (573°C), the crystalline quartz in the clay body increases in volume by 1%. This may cause cracking if the temperature in the kiln is increased too rapidly.
Ring the bells that still can ring, forget your perfect offering
There is a crack, a crack in everything, that’s how the light gets in
Excerpt from “Anthem,” by Leonard Cohen
Organic matter in the clay is burned and oxidized to carbon dioxide, and fluorine and sulphur dioxide from materials in the clay body are driven off at 1292–1652°F (700–900°C).
At this point the “biscuit firing” is completed. The clay particles are sintered or welded together. The ware has undergone little shrinkage since the bone-dry stage, but it is durable enough to withstand handling and glazing.
Above 1652°F (900°C), the clay body begins to shrink and vitrify. The silica starts to melt, filling the spaces between the clay particles and fusing them together. The fired clay is known as “metakaolin.”
Note that the material has been transformed, and we’re not even done.
At 1832°F (1000°C) the clay crystals begin to break down and melt.
At 1922°F (1050°C), needle shaped crystals of mullite 3Al2O3•2SiO2 begin to form, giving the fired clay strength and hardness.
When mullite forms from metakaolin, extra free silica is released.
Above 2012°F (1100°C), any free silica (not chemically combined) in the clay changes to cristobalite, which has a different structure from that of quartz.
When the kiln is cooled down, cristobalite contracts suddenly by 3% at 439°F (226°C).
This too can cause cracking if the kiln is cooled too rapidly by opening too soon, causing some areas to drop in temperature and stressing the ware. It is advisable not to open it until it has cooled down to below 212°F (100°C).
Slow and steady, right?
Although the process of firing a clay vessel renders it more durable, the container still vulnerable to breakage if subjected to sufficient shock or trauma, for once the quality of pliability is removed, the vessel is rigid, but fragile.
Broken ceramics cannot be returned to its original form, but they can still provide utility through various journeys towards reuse.
For example, they can be crushed to create solid pavements upon which our children can learn to take their first steps, or ceramic roofing tiles, providing shelter for our vulnerable from the elements, the reuse path depending upon the quality of the broken ceramic material as it is processed at the recycling facility.
There are some who have made this one-way journey through the kilns, so to speak, and have emerged rigid, fragile, their quality of pliability removed.
It’s important that we consider the role each person plays in the recreation and revival of our communities, even those who have emerged rigid, fragile, and broken from experience.