Brenda G. Anderson on mon 9 oct 06
Thanks for all who responded a few weeks ago about my venture into =
building my first small raku kiln.
I am gathering the materials for a garbage can one (starting out small). =
But I have another question. Do I need an analog pyrometer? I have =
made a casting and tube out of stoneware to attach on the side of the =
garbage can to insert the pyrometer.
My question is: will I melt the box with the reading whenever stick in =
the pyrometer? I have no idea how to do this or even if it is a =
problem.
Brenda G. Anderson
Daughter of Clay Pottery
Lower Alabama where we have two seasons: summer and winter in February
Cindy Gatto on mon 9 oct 06
We don't use a pyrometer when we raku. We have learned to watch the kiln. We
watch the glazes and the color of the kiln. Mostly the glazes. We wait for
the glazes to bubble up and get crater like and then they smooth out and we
know it's time. It took some experimentation for us to learn our kiln but we
know it now so it was worth it in the long run. There is an article in the
recent Clay Times about analog pyrometers. Based on that article I don't know how
useful an analog would be. The article, by Marc Ward talks about how analog
pyrometers don't respond that quick. They take a bit of time to climb and
between that and the fact that a raku firing is so fast I don't know how
effective it would be. I go for the more intuitive approach of learning your kiln by
sight, sound, feeling. But that's just me. I do suggest the article it's an
eye-opener I am actually waiting for the next issue when he is going to talk
about digital and Infra red ones.
Cindy Gatto & Mark Petrin
The Mudpit
228 Manhattan Ave
Brooklyn, NY 11206
718-218-9424
_www.mudpitnyc.com_ (http://www.mudpitnyc.com/)
mudpitnyc@aol.com
Craig Clark on mon 9 oct 06
Brenda, in the interest of keeping things simple to begin with,
scratch the pyrometer. You do not need one for Raku, especially if it is
a small garbage can model. After a few fires you will get the idea of
about what the color of the atmoshpere in the kiln ought to be at about
the time your glaze has matured. It is a good idea to leave yourself a
"spy port" that you can look through to see the side of your pieces
about half way down the side of the kiln. You can just use the hole for
the pyrometer for this if it is large enough diameter. You will also be
looking through the hole in the top of your kiln. You will be firing by
sight.
The thing to look for is a smooth reflective surface on you gloosy
pots. If you don't have a gloosy glaze, get one. Just one in each round
gives you a very good means by which to judge the optimal time to pull
your pots. As the glaze matures it will first start to bubble, and then
it will smooth out. The smooth surface give you a nice reflection of the
flame in the kiln.
Remember, with Raku you have more of what I like to call "slop
room." Variations between pots and firings are not just sought after but
expected. The firing of the kiln is like a dance. There will be
variations in rythm and cadence. The better you know you kiln the easier
it will be. You will be able to listen to your burner and tell if things
are firing correctly.
At some point, you'll get to where you just kinda know when things
are ready to go. You will be able to quickly glance at the color of the
atmoshpere to determine whether it's time to pull your pots or not. Just
go with the flow of the firing. NO rush. No muss or fuss. Don't play
with the kiln. The biggest trouble folks often have is learning to not
use too much gas, not trying to get up to temp at record speed, and
learning how to adjust the gas/air ratio at the burner. With a little
kiln it doesn't take a whole lot of ummph to get things up to cone.
Hope this helps
Craig Dunn Clark
619 East 11 1/2 St
Houston, Texas 77008
(713)861-2083
Brenda G. Anderson wrote:
> Thanks for all who responded a few weeks ago about my venture into building my first small raku kiln.
>
> I am gathering the materials for a garbage can one (starting out small). But I have another question. Do I need an analog pyrometer? I have made a casting and tube out of stoneware to attach on the side of the garbage can to insert the pyrometer.
>
> My question is: will I melt the box with the reading whenever stick in the pyrometer? I have no idea how to do this or even if it is a problem.
>
> Brenda G. Anderson
> Daughter of Clay Pottery
> Lower Alabama where we have two seasons: summer and winter in February
>
> ______________________________________________________________________________
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at melpots@pclink.com.
>
>
Snail Scott on tue 10 oct 06
On Oct 9, 2006, at 4:41 PM, Brenda G. Anderson wrote:
> Thanks for all who responded a few weeks ago about my venture into
> building my first small raku kiln.
>
> I am gathering the materials for a garbage can one (starting out
> small). But I have another question. Do I need an analog pyrometer?
Skip the pyrometer. Firing by eye will be
better in many cases anyway, and perfectly
adequate in most. Just give yourself a
decently located spyhole.
If you _want_ a pyrometer, that's your
choice, but need one? No, definitely not.
-Snail
Robert Edney on tue 10 oct 06
Hi,
We fire raku several times a week and yes, we use a pyrometer. However,
it's for convenience only. If you've got one, you might as well use it.
The probe of the pyrometer is made to withstand the kiln temp and atmosphere
and you can safely leave it inserted all the time (this assumes that it's
designed for kiln use). Raku fires in a range where you can actually see
the glaze melt, and you want to. It's a much better way of judging when to
pull a piece. Line at least one pot up with the peephole so that you can
see the edge of the pot. Some glazes take awhile to settle down after
reaching maturity, and temperature alone is not the best guide. By sighting
over the edge of the pot (the profile) you can see if there are any bubbles
and if the glaze has leveled out and taken on some gloss (assuming it's a
glossy glaze, but even a matter will show some gloss in the kiln). Our raku
kiln is in between the kitchen and the studio, and it's easy to walk past,
glance at the pyro and see what stage the firing is at. You will eventually
become a very good judge of glaze melt and temperature based on color inside
the kiln. I'd love to hear how your first firings go!
Robert
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Brenda G.
Anderson
Sent: Monday, October 09, 2006 2:41 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: small raku kiln/pyrometer
Thanks for all who responded a few weeks ago about my venture into building
my first small raku kiln.
I am gathering the materials for a garbage can one (starting out small).
But I have another question. Do I need an analog pyrometer? I have made a
casting and tube out of stoneware to attach on the side of the garbage can
to insert the pyrometer.
My question is: will I melt the box with the reading whenever stick in the
pyrometer? I have no idea how to do this or even if it is a problem.
Brenda G. Anderson
Daughter of Clay Pottery
Lower Alabama where we have two seasons: summer and winter in February
____________________________________________________________________________
__
Send postings to clayart@lsv.ceramics.org
You may look at the archives for the list or change your subscription
settings from http://www.ceramics.org/clayart/
Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.
Ivor and Olive Lewis on wed 11 oct 06
Anyone following Snail's advice about eyeballing the spy hole of a kiln =
should take care of their sight by wearing some form of Infra Red and =
Ultra violet Eye protection. No. 3 welding goggles would seem to be the =
cheapest option.
Though the temperature of a Raku firing might seem fairly low your eye =
will focus any heat onto your Retina and may leave a burn scar.
Take good care of your sight.
Best regards,
Ivor Lewis.
Redhill,
South Australia.
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