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mystery kiln help please!

updated thu 29 jul 99

 

Jon Kirkendall on fri 23 jul 99

Hi all,

Okay, here's the situation: A few years ago, a potter in the area
died, and a friend of mine purchased this potter's kiln. My friend owns
a Huge and Unweildy Kiln, and bought this smaller gas kiln with the
thought that it would enable her to fire more often. This smaller gas
kiln had a reputation for easy, consistent firings. Now, my friend
located the small gas at another potter's house, someone with no
experience in gas firings. The friend who who bought the kiln has never
fired with Venturi burners (I have) and does not have the firing
schedule, and the friend where the kiln has been located has never fired
a gas kiln (I have). Both are looking to me for some sort of leadership
in getting this thing going. It is all hooked up to the gas line
(natural gas) with four NEW venturi burners ready to go EXCEPT:

1) No bagwall
2) No known firing schedule
3) 1/8th" or 1/16th" wide crack, running about 18" from front to back in
the bottom that developed during transport.

The kiln is a down draft brick kiln, with four burners, two on each
side. It is about 38" from the floor to the top of the arch, 33" deep,
and 33" wide. It has a hinged brick door that screws shut. The damper
seems to be a piece of slate/shelving that sits on top of the chimney.

I have checked the archives and haven't found much that would help me
identify this kiln I need some direction about building a bag wall and
a firing schedule. And, what's the best way to patch this crack that
developed? Can I stuff it with fiber?

Thank you.

Jonathan in DC,
trying to figure out how to throw with this new gold ring on his left
hand.

Earl Brunner on sat 24 jul 99

So far so good, what you didn't say was whether the burners where under the
kiln pointing up or on the sides burning sideways. IF they are underneath
and point up, you may not need a bagwall at all. My Geil fires just fine
without bagwalls. In factI only have about a three or four inch combustion
"chamber" up each side. The first few firings are going to be learning
experiences in any case, I put cone packs all over the place my first few
firings. I also put oxy/reduction sensitive clay and lgazes all over the
place so that I could get an idea what was going on. I learned for example
(probably soemthing I once knew, but forgot ) that I needed to stagger the
two sidebyside shelves so that there was a good flow and circulation down
through the middle. A pyrometer would be great to help determine rate of
temperature change as you turn up the gas etc.

Jon Kirkendall wrote:

> ----------------------------Original message----------------------------
> Hi all,
>
> Okay, here's the situation: A few years ago, a potter in the area
> died, and a friend of mine purchased this potter's kiln. My friend owns
> a Huge and Unweildy Kiln, and bought this smaller gas kiln with the
> thought that it would enable her to fire more often. This smaller gas
> kiln had a reputation for easy, consistent firings. Now, my friend
> located the small gas at another potter's house, someone with no
> experience in gas firings. The friend who who bought the kiln has never
> fired with Venturi burners (I have) and does not have the firing
> schedule, and the friend where the kiln has been located has never fired
> a gas kiln (I have). Both are looking to me for some sort of leadership
> in getting this thing going. It is all hooked up to the gas line
> (natural gas) with four NEW venturi burners ready to go EXCEPT:
>
> 1) No bagwall
> 2) No known firing schedule
> 3) 1/8th" or 1/16th" wide crack, running about 18" from front to back in
> the bottom that developed during transport.
>
> The kiln is a down draft brick kiln, with four burners, two on each
> side. It is about 38" from the floor to the top of the arch, 33" deep,
> and 33" wide. It has a hinged brick door that screws shut. The damper
> seems to be a piece of slate/shelving that sits on top of the chimney.
>
> I have checked the archives and haven't found much that would help me
> identify this kiln I need some direction about building a bag wall and
> a firing schedule. And, what's the best way to patch this crack that
> developed? Can I stuff it with fiber?
>
> Thank you.
>
> Jonathan in DC,
> trying to figure out how to throw with this new gold ring on his left
> hand.

--
Earl Brunner
http://coyote.accessnv.com/bruec
mailto:bruec@anv.net

Mike Bailey on wed 28 jul 99

In message , Jon Kirkendall writes

about firing a new kiln.

Dear Jonathan,

Firing any kiln for the first time tests your understanding of the
firing process. I'd suggest drawing your ideal firing graph. e.g.

I'd aim at doing a steady rise for 8 hrs to 950 or just below 1,000 deg
C. when I'd start reduction. Then hold the temperature for circa 15
minutes by making the kiln reduce (I prefer to do this with back
pressure by blocking the pull of the chimney. Then ease off the
reduction slightly - allowing a gradual rise to the final cone. Of
course, your firing graph, based on your experience, may be different to
this.

Obviously you'll need to find the burner settings to make the kiln
follow the graph. Keep notes. Tweak the settings next time to get closer
to the graph. You might just start on one or two burners,

You can quite often get away without having a bag wall - the test will
be if the work gets over-fired at this point. If your intuition is that
it needs a bag wall put one in - you can make bag walls with cut down
kiln shelves, providing the cut has been at right angles the shelf will
stand vertically on its edge. It may only need to be 4 - 6" high though.

Rhodes says it takes 40 firing to learn how to fire a kiln. I was still
tweaking the firing regime of my last kiln, on it's last firing, having
done 170 firings. Perhaps I'm a slow learner!

Final bit of advice, go from first principles.

Cheers,

Mike Bailey.

>----------------------------Original message----------------------------
>Hi all,
>
>Okay, here's the situation: A few years ago, a potter in the area
>died, and a friend of mine purchased this potter's kiln. My friend owns
>a Huge and Unweildy Kiln, and bought this smaller gas kiln with the
>thought that it would enable her to fire more often. This smaller gas
>kiln had a reputation for easy, consistent firings. Now, my friend
>located the small gas at another potter's house, someone with no
>experience in gas firings. The friend who who bought the kiln has never
>fired with Venturi burners (I have) and does not have the firing
>schedule, and the friend where the kiln has been located has never fired
>a gas kiln (I have). Both are looking to me for some sort of leadership
>in getting this thing going. It is all hooked up to the gas line
>(natural gas) with four NEW venturi burners ready to go EXCEPT:
>
>1) No bagwall
>2) No known firing schedule
>3) 1/8th" or 1/16th" wide crack, running about 18" from front to back in
>the bottom that developed during transport.
>
>The kiln is a down draft brick kiln, with four burners, two on each
>side. It is about 38" from the floor to the top of the arch, 33" deep,
>and 33" wide. It has a hinged brick door that screws shut. The damper
>seems to be a piece of slate/shelving that sits on top of the chimney.
>
>I have checked the archives and haven't found much that would help me
>identify this kiln I need some direction about building a bag wall and
>a firing schedule. And, what's the best way to patch this crack that
>developed? Can I stuff it with fiber?
>
>Thank you.
>
>Jonathan in DC,
>trying to figure out how to throw with this new gold ring on his left
>hand.
>

--
Mike Bailey