Frank Gaydos on tue 28 may 02
Here is a very nice Photo Essay of brick makers in Afghanistan. Think =
you pack a kiln tightly? Hah!
http://www.usnews.com/usnews/photography/brick/brick1.htm
Frank Gaydos
Gavin Stairs on wed 29 may 02
A beautiful essay. Thanks for the pointer, Frank.
I thought at first that they were firing in a clamp, but then I saw the
kiln walls. It seems that this is a transition type of kiln, of very
ancient design origins. Just a bit later than the stacked ware piles with
turves or shards for walls. The kiln appears to be a more or less straight
sided cylinder with an open top, and probably, although the photos don't
show this, arched fire tunnels under the stack made of loosely stacked
brick. Even though they are only firing to terra cotta temperatures, they
have to fire for 4 days. That must be testament to the density of the
stacking, and the poor airways.
The essayist says that the outside green bricks are there for
insulation. I rather suspect that they are more there to dry. I bet
there's a well defined arrangement of bricks inside the kiln, stacking the
driest bricks near the fire pits, and then filling with wetter bricks,
until the final outside layer is of really green bricks. With the open top
of the kiln, I would guess that several layers there would be under-fired,
and they would probably be re-stacked near the fire next time. The firing
front probably progresses through the kiln as much by drying as by
temperature rise. That is, the heat probably goes to evaporating water as
much as it goes to raising the brick temperature to maturity.
If I'm right about this, then what we are looking at is really a sort of
progressive, or continuous kiln, like a tunnel kiln, but so disastrously
arranged that it has to be dismantled in order to advance the bricks though
the heat zones. Fascinating, but I wish the photographer had been a
ceramics person, to tell us more about the process.
Gavin
At 09:19 PM 28/05/2002, Frank Gaydos wrote:
>Here is a very nice Photo Essay of brick makers in Afghanistan. Think =
>you pack a kiln tightly? Hah!
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