mel jacobson on sun 22 jul 01
another factor that john baymore did not mention,
is the factor of dewpoint. (am i mixing humidity and temp/?)
when all the things in the kiln, the shelves, posts, pots and
walls have reached an apex temp. ( the potter determines the
apex temp.) it is ideal to get all these elements to the same
temp, at the same time. this is the industry standard.
one of the things that i do to facilitate this phenomenon is to
lift the kiln off its base.
i use expanded metal...or, anthing that lets air under the kiln.
feriz delkic feels that air transmission is vital in getting perfect
dewpoint.
i place concrete block, leaving at least two inch gaps in the block,
to a pre determined height...(the height of the potter loading is
critical.) I also like leaving about two inches of block extending
beyond the kiln as this leaves a wonderful place to put the banding
metal around the base of the kiln...extra block in the back of the
kiln makes a resting place for the burners. block is cheap and
it should be used to your advantage. it is almost like having a
table at the back of the kiln.
i put a complete layer of expanded metal over the block, making
sure that it is level. the first layer of hard brick is placed on the
expanded metal*. then a layer of used or not pretty soft bricks.
then the hard brick floor. as you can see, the kiln floats.
air can come through the bottom of the kiln. and the soft brick
adds the insulation factor needed for the bottom.
feriz says that all potters do it wrong....just stack brick on a solid
block base, or a concrete pad. lifting the kiln, that seems to be
the answer.
that is why he likes to have legs on his kilns, especially high temp kilns
used for military heat treating...(2800F.)
sometimes we just get used to doing things one way. if we look
to industry, and the many ceramic engineers that are working to
save money, time, and make a perfect product...well, we learn
things. the way we built kilns in 1960 is not necessarily the
way we should build them in 2002.
round, or arched, square or flat...heat does not care. it just
builds in the kiln. as john has pointed out, or read nils lou
or olson. we have a lot of goofey ideas as back yard potter, that are not
correct, and never will be correct. bad science.
some turbulence is good in a fuel kiln...too much is bad. soft burners
like mine just never create turbulence...so, i add a great deal of
wood as i fire. early for reduction, and some at the end, just to
make things happen. i have never used blowers, and i should
i believe, but, i try to make things happen with what i have.
the new hank method of firing has changed my mind a great deal.
firing down with reduction for salt and soda as gail nichols does,
well, it has changed my mind. we did that at hay creek, at it worked
a magic..(thanks dock six women.)
a great deal to learn. i read my science magazine every quarter
from acers....of course i belong...who would not?...what i glean
from those engineers is worth the cost. it is hard reading...complex
with graphs i do not understand, but the basic information is clear.
why would we throw away that information? my god, these are
smart folks, doing things that save millions of dollars in fuel and
product loss. do we ignore that information, and say `well, wally
nelson said to me in 1955 thus and thus and thus....`
well it was probably b.s. in 1955. join the society we live in...that
is why i have email, computers, scanners, digital cameras....it is
important stuff. it belongs to our time.
we do not turn stupid just because we pass 65. some do, because
they refuse to join their world.
even nils lou has finally purchased a pc...with windows 98.
(his mac is sulking in the corner.)
mel
* check with any steel supply company about expanded
metal. it comes in a variety of sizes and thickness'.
it sure beats hell out of the stuff the norweigian potter used
to build his wood kiln...pine, and it burned down the first
time he fired it.
nils lou has designed a new burner...man, is it nice.
ask him about it.
state of the art.
marc ward makes wonderful burners...ask him about them.
we have good folks to help us...use them. it is not 1955
technology.
From:
Minnetonka, Minnesota, U.S.A.
web site: http://www.pclink.com/melpots
Hank Murrow on thu 26 jul 01
>another factor that john baymore did not mention,
>is the factor of dewpoint. (am i mixing humidity and temp/?)
>
>when all the things in the kiln, the shelves, posts, pots and
>walls have reached an apex temp. ( the potter determines the
>apex temp.) it is ideal to get all these elements to the same
>temp, at the same time. this is the industry standard.
>
>one of the things that i do to facilitate this phenomenon is to
>lift the kiln off its base.
>
>i use expanded metal...or, anthing that lets air under the kiln.
>feriz delkic feels that air transmission is vital in getting perfect
>dewpoint.
>
Dear Mel;
When I was teaching and building kilns at Anderson Ranch '70_'73 we
learned to place a piece of sheet galvanized between the block foundation
and the brickwork of the kiln. The reason we did this was to create a vapor
barrier so the kiln wasn't sucking up moisture from the snow covered ground
all around the kilns. It made a huge difference in firing times for the
kilns we did this to. If I ever build another brick kiln I will try your
expanded metal idea and get the air in there too!
Cheers, Hank
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