mel jacobson on wed 26 oct 11
the oxyprobe is a wonderful tool, expensive, easy to break
and costly to repair. in other words, it is a `jaguar` car.
i like a solid ford pick up truck.
many have spent a great deal of money thinking the
oxyprobe would fire their kiln for them...that does not work.
i have had two of them, and did the early review and
research for pmi and did the first article about them.
both of mine are in the trash bin.
my research still stands. the tool is expensive, breaks easily
and is expensive to repair. it is not for every potter. it works
best when used as a learning tool. it will help you understand
how your kiln works. once you know..put the oxyprobe away
in a silk lined box. or, if you have a need for repeat firing
systems, in other words, sets of dishes matched from firing
to firing...use the oxyprobe all the time. and keep it maintained.
(can you say `professional need`?)
the tool works as advertised. it will read temp and reduction.
very close measurements. it is basically a amp meter/volt
meter etc. with a platinum thermocouple. it works.
but, the price is very high...and any item that gets close to
a thousand dollars should be thought through carefully.
pug mill vs. oxyprobe=3D pug mill.
my take has always been: learn your kiln and the back pressure
it creates. learn your burners and how to move heat around your
kiln with damper/gas pressure/and primary air.
high gas, what does it do?
low gas, what does it do?
one burner high, one burner low...what does it do?
damper in, damper out. how much reduction do you really
need to make perfect pots?
long warm up and what does it do for you?
over stacked kilns, what does it give you?
knowing how to bisque fire may just save you hundreds
of ruined pots. as many know, bad bisque is the cause of
most cracking, and glaze flaws.
the rule is: bisque slow, glaze fire fast, then slow down.
how you cool your kiln has more to do with great pots than
slow firing.
perhaps the worst scenario is: `hey charlie, i got every one of those
damn pots into the kiln...she is stuffed to the gills, i am a green
loader.` bull crap. that kiln will not fire well, and about 50 percent
of the pots will be seconds. thinking green and doing crap. waste
is the big polluter. work for 100 percent perfect pots. and, that means
you leave some out for the next firing. and firing with a perfectly balanc=
ed
kiln will save fuel.
same for an electric kiln. do not stuff them. leave room for the
heat to move around. the new rule: a thumb width between pots.
and a fist width between shelves. try it....don't be a `we always do
it this way.`
i got a great email from one of our `follow mel's book` folks.
she is firing our protocol to the letter. the bottom line is:
she loves her pots, the kiln fires fast and in balance. she is
saving gobs of propane and best of all, she fires in one morning
afternoon, and no waiting forever for her kiln. time and frustration
ended. (and, best of all, she no longer thinks of herself as an old
lady with limited skill.)
happy potter. (she will be writing a long/well documented story
of her kiln building, firing. it will appear on the 21st century website.
and remember, there is tons of free information and help on that site.)
mel
from: minnetonka, mn
website: http://www.visi.com/~melpots/
clayart link: http://www.visi.com/~melpots/clayart.html
Lee on wed 26 oct 11
On Wed, Oct 26, 2011 at 7:47 AM, mel jacobson wrote:
> the oxyprobe is a wonderful tool, expensive, easy to break
> and costly to repair. =3DA0in other words, it is a `jaguar` car.
>
> i like a solid ford pick up truck.
These are sort of "Ford Trucks, with extended cab". I've seen them
used for around $100.00:
http://www.bacharach-inc.com/fyrite-gas-analyzers.htm
http://www.bacharach-inc.com/PDF/Brochures/fyrite_gas_analyzers.pdf
http://www.bacharach-inc.com/PDF/Instructions/11-9026.pdf
--
=3DA0Lee Love in Minneapolis
http://mingeisota.blogspot.com/
=3DA0"Ta tIr na n-=3DF3g ar chul an tI=3D97tIr dlainn trina ch=3DE9ile"=3D9=
7that is, =3D
"The
land of eternal youth is behind the house, a beautiful land fluent
within itself." -- John O'Donohue
William & Susan Schran User on thu 27 oct 11
On 10/26/11 8:47 AM, "mel jacobson" wrote:
> the tool works as advertised. it will read temp and reduction.
> very close measurements. it is basically a amp meter/volt
> meter etc. with a platinum thermocouple. it works.
> but, the price is very high...and any item that gets close to
> a thousand dollars should be thought through carefully.
Got one for our gas kiln at school as a teaching tool and out of curiosity
to see how I was doing with the firings using sight and sound.
Pretty darn close - realized I was probably reducing a bit late (have
started 100F earlier), was closing damper too much (now opened 1/4" wider
for early reduction) and could open damper a bit more at higher temperature=
s
(about 1/8" more open).
As Mel also wrote, how one stacks the kiln is perhaps one of the most
critical things that is often ignored. I have found with the downdraft Geil
I MUST have the first set of kiln posts high enough so the next shelves are
at least as high as the flue opening across the bottom of the kiln. This is
critical for me to get even temperature top to bottom. Of course staggering
the shelves is the next MUST do thing.
Bill
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
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