[Clayart] firing a bit faster

mel jacobson melpots at mail.com
Mon Sep 6 13:03:45 UTC 2021

We have fired the big salt kiln here at the farm several times
this late summer.  It is a huge reminder of what firing a hard brick
kiln is like.  It is a throw back firing to 1950 and of course
much earlier.

It is like the discussion of zinc, there are a great many things to know
and understand if you are a "do it yourself" artist/potter.

All kilns were made of hard brick, mostly 9 inches thick before and after ww2.
There were standards of firing practice that had a great deal more to do with
how they fired and timing rather than changing how to fire.  The kilns just fired
in 12 hours. They took 24 hours to cool.  And when that is how they worked, the standard
for firing was set. It was just.."that is just the way it is."  The teachers told
us how to do it...it became "law".

After the first atomic bomb work, smashing atoms, nose cones of rockets, extreme
heat work and the first use of ceramic melted to fiber, spun into Kaowool
and the use of saw dust in the brick.."IFB's" did the standard for firing change.
But the "law was in place".  Long warm up, slow firing, fire to cone 10 just half over.
Slow cool as long as you can.

When Nils and I started to "fast fire", as it is called, we were looked at with great suspicion.
"Can't do that you know."  Warm the kiln overnight, even though you have a perfectly insulated
kiln.  And of course that warm up destroys the K factor and the insulation. Does not matter, the
kiln and pots like slow.

anyway, it seems that a few are starting to understand that well dried, well balanced clay bodies
with fine sand or grog can be fired much faster than the old law required. It was nothing but a huge
fuel waster. It is an old rule.....If I fire my 45 cubic inch kiln in 6 hours and another potter
fires their kiln in 12 hours..."under house rules" who wins the ecology war.  I do.  And I save
gobs of money.

The new rules are based on "how does your kiln fire?"   Most potters have no idea because they
still use the old rules for hard brick firing. Find the magic timing of your kiln.( of course we
still have people writing code for auto kilns that use 1955 standards of firing practice.)
"you are firing too fast."  "shut up, leave me alone, don't tell me what to do."

Just a reminder. Your ifb kiln with good gas pressure, or electric power will serve you well. My pots
love cone 11, fired in 5 hours. But, I make a clay body and glazes that adore the firing
system.  You sure cannot take a cone 9, tight, pure white clay and rush the system. It is all
about the logic of what you are doing. Just more food for thought.

It is like magic amulets on your kiln...""When you fire with logic, the amulets work well."

website: www.melpots.com

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