mel jacobson on tue 19 dec 06
industry faces the problem of kiln destruction all the time.
think of the toxic, corrosive stuff that steel mill kilns,
aluminum smelting and of course atomic energy
and exotic kilns are faced with.
potters are not unique with salt/soda kilns.
to replace every year, a $300,000++ kiln in industry,
is a huge financial problem.
ceramic engineers and chemist are constantly looking
for better ways to protect kilns. ceramic fiber is
becoming the standard. (modules) and when that fiber is coated
with quality materials such as itc, the kilns may get
2 or 3 times their life span. that could be a million
dollar saving for a big company. then take the
energy cost of running a kiln or heat treating kiln
for 24/7/345 (twenty days to repair each year.)...it runs in the millions.
as ivor as pointed out...perhaps bricks are being
made that will work better, give longer life.
and, that becomes the huge problem for
potters...often they think...`well hell wally,
a hard brick is a hard brick, and soft brick
are all the same...and well, fiber is fiber.`
not so at all.
in fact...the cheap on sale fiber is
generally not worth working with.
dense, tightly woven fiber will last ten
times as long.
vince has found a quality hard brick...and that
is very important. we should listen to him.
shipping and your location is critical in hard
brick acquisition. often you cannot get
the brick you want. and shipping from
kentucky to oregon is out of the question.
i am copying this note to tim frederich and asking him
to give us some tips on buying brick.
i know he is very busy, but he may have some
ideas.
i am not an expert in the brick industry, but
i do know that bargain brick can often be
the worst purchase you will ever make.
i am still using, and have configured four kilns
in my studio from high quality ifb's i bought
in 1965. that means thousands of firings.
i have added new brick as the kiln has grown
in size...but at least half of the brick are original.
they are all coated with itc 100 and 256.
the kiln looks brand new.
one of the first questions nils asked me when i
was working on the iron saga problem...`how
is the kiln holding up...has the roof sagged?`
not a 1/16 of an inch...and the itc has held up
perfectly...over 15 firings to cone 13+. that old
flat top is well made...from quality materials.
and, that makes the decision to buy the best
and the most expensive when i built years back
has paid me a hundred times over.
so, i want to thank those that have given information
about brick and salt/soda...ivor, vince, hank, edouard,donovan
and many others. this is important technical information
that is critical for potters to understand.
it is what separates clayart from being a `chat group`.
it is what many do not understand about clayart...they
mock it , and say it is just an `internet busy body chat group`.
little do they know.
mel
from: mel/minnetonka.mn.usa
website: http://www.visi.com/~melpots/
Clayart page link: http://www.visi.com/~melpots/clayart.html
Ivor and Olive Lewis on thu 21 dec 06
Dear Mel,=20
I spent seven years of my life two in metallurgical laboratories. Been =
involved with springs and magnets but in the end I specialised in alloys =
that were "Designed" to be resistant; to Abrasion, to Impact, to =
Corrosion, to High Temperature. Vapour glazing hardly compares with some =
of the problems I have solved.
Had a client who was processing a cement wood fibre composite. He was =
wet sawing the stuff and had to break ever half shift to remove the =
blunt saw and replace it with a newly sharpened one. A combination of =
abrasion and corrosion. new saw blades each week. I treated one of his =
saws FOC. Went back a week later. My protege saw was still cutting the =
stuff like a hot knife through butter on a summer's day. A month later =
it was still doing the same thing. After six months the steel behind the =
coating I had applied had abrade away and the possibility of a flying =
tip became a possible hazard for the machine operator. Think of time =
saved and an extra hours of production each day. They had a hard time =
getting the old blade off. Nuts and bolts had all corroded into position =
then became covered with hard cement.
Which is why I asked my original question, "What is Service =
Specification for a Kiln Wash". That is the way I was Trained. How can =
people find an answer if they do not know what the questions are. The =
new question would be "What are the specifications for Shelf or Batt =
Wash"
I thank everyone who gave me food for thought.=20
The Chemistry of a kiln where the glazing agent is Sodium Chloride =
differs from the Chemistry when Sodium Carbonate is use. Nor did we =
extend to topics like Silicon Carbide Shelving and the influence of the =
level of oxygen in a kiln atmosphere.
Thanks for the "Mention"
Best regards,
Ivor.
| |
|
