Deborah Thuman on mon 28 jun 10
It's summer, temps are getting to upper 90's and low 100's. How
necessary is it to candle a gas kiln overnight in this weather? For
those who fire gas in the southwest during the summer.... do you
candle? For how long?
Would it damage my work or the kiln if I started with a low flame, and
raised the flame bit by bit until I got a red glow from inside the
kiln and then proceeded with the firing?
Many thanks.
Deb Thuman
http://debthumansblog.blogspot.com/
http://www.etsy.com/shop.php?user_id=3D5888059
http://www.facebook.com/pages/Deb-Thumans-Art-Page/167529715986
Snail Scott on mon 28 jun 10
On Jun 28, 2010, at 11:26 AM, Deborah Thuman wrote:
> ...For
> those who fire gas in the southwest during the summer.... do you
> candle? For how long?
As the saying goes, it ain't the heat, it's
the humidity. In a dry environment, both
the clay and kiln will be fairly dry, and little
candling may be needed. The tightness of
the body is probably more relevant. Even in
a very wet climate, though, candling all night
is seldom (if ever) necessary. Candling
overnight is mainly a convenience, as it gets
it out of the way and allows the firing to get
rolling into the high temps earlier in the day.
Candling that begins the morning of the firing
just means a firing that runs later into the
day or night.
I work thicker than most people, and candling
for the whole night (6-8 hours) is _way_ more
than is usually needed. For some kilns, though,
that overnight jump-start is the difference between
shutting down before dinnertime (or at least by
bedtime), and being up half the night. Convenient,
but it's paid for in added firing cost. If candling on
the morning of the firing doesn't make for an
unworkable time frame with your kiln and firing
schedule, go ahead and do it! Why waste fuel
or power? If it is truly unpleasant to do the whole
job on one day, though, then by all means candle
overnight so you can be fresh and alert when you
finally reach temperature, and can avoid stupid
fatigue-based choices.
> Would it damage my work or the kiln if I started with a low flame, and
> raised the flame bit by bit until I got a red glow from inside the
> kiln and then proceeded with the firing?
Ummm...that's exactly what candling is. Why
do you think it might be a problem? I can't
imagine why candling would be damaging
to any work. NOT candling...now that's taking
a risk!
-Snail
KATHI LESUEUR on mon 28 jun 10
Deb,
I never candle my gas kiln. I have four forced air burners. I turn on
the bottom two very low, and with out the air turned on (they act
like a venturi) until the kiln is at about 800 degrees.Then I
increase the gas and add air. After three hours it around 1150. I
then turn the other two burners on full blast. Never had a problem.
Could be my clay. Don't know, but it works for me.
KATHI LESUEUR
http://www.lesueurclaywork.com
On Jun 28, 2010, at 12:26 PM, Deborah Thuman wrote:
> It's summer, temps are getting to upper 90's and low 100's. How
> necessary is it to candle a gas kiln overnight in this weather? For
> those who fire gas in the southwest during the summer.... do you
> candle? For how long?
>
> Would it damage my work or the kiln if I started with a low flame, and
> raised the flame bit by bit until I got a red glow from inside the
> kiln and then proceeded with the firing?
>
> Many thanks.
>
> Deb Thuman
> http://debthumansblog.blogspot.com/
> http://www.etsy.com/shop.php?user_id=3D5888059
> http://www.facebook.com/pages/Deb-Thumans-Art-Page/167529715986
>
Craig Martell on mon 28 jun 10
At 09:26 AM 6/28/2010, you wrote:
>It's summer, temps are getting to upper 90's and low 100's. How
>necessary is it to candle a gas kiln overnight in this weather?
I don't think it's necessary to candle a kiln at all. Well, in most
cases. If your pots are bisque fired and the glazes are dry you can
just fire the kiln from ambient temp. without candling.
I have a 66 cubic ft. downdraft with 2 inspirating burners. They are
Buzzers made by C.H. Hones Co. I start the fire by warming for a
half hour with the pilot burners. Then I lite the Buzzers and give
them just enough gas to stay lit with a gentle flame. Then, after
another half hour the Buzzers are turned up to 0.25 PSI. An hour
later they go to 1.0 PSI. Another hour and they are turned up to 2.0
PSI and stay there until I put the kiln into reduction at cone
06. At this point the burners are at full flow which is 3.0 PSI. It
takes 11 to 12 hours to fire from ambient temp to cone 10. I use
propane for fuel.
regards, Craig Martell Hopewell, Oregon
steve graber on mon 28 jun 10
skip the candle!=3DA0 we're at some 20% humidity in southern california.=3D=
A0 p=3D
retty dry.=3DA0 at best candling is "intended" to remove moisture and the e=
nv=3D
ironment seems to do that just fine.=3DA0 =3D0A=3D0Ai fire away!=3DA0 slowl=
y tweaki=3D
ng the burners up and up.=3DA0 =3D0A=3D0Ai hear in Yuma, Arizona they just =
leave =3D
their work in the backyard all day and it'll be 07 by 8pm.=3DA0 =3D0A=3DA0S=
teve G=3D
raber, Graber's Pottery, Inc=3D0AClaremont, California USA=3D0AThe Steve To=
ol -=3D
for awesome texture on pots! =3D0Awww.graberspottery.com steve@graberspott=
er=3D
y.com =3D0A=3D0A=3D0AOn Laguna Clay's website=3D0Ahttp://www.lagunaclay.com=
/blogs/ =3D
=3D0A=3D0A=3D0A=3D0A----- Original Message ----=3D0A> From: Deborah Thuman =
@ZIANET.COM>=3D0A> To: Clayart@LSV.CERAMICS.ORG=3D0A> Sent: Mon, June 28, 2=
010 =3D
9:26:42 AM=3D0A> Subject: Question for those who fire gas kilns=3D0A> =3D0A=
> It's=3D
summer, temps are getting to upper 90's and low 100's. How=3D0Anecessary i=
s =3D
=3D0A> it to candle a gas kiln overnight in this weather? For=3D0Athose who=
fir=3D
e gas in =3D0A> the southwest during the summer.... do you=3D0Acandle? For =
how =3D
long?=3D0A=3D0AWould =3D0A> it damage my work or the kiln if I started with=
a low=3D
flame, and=3D0Araised the =3D0A> flame bit by bit until I got a red glow f=
rom =3D
inside the=3D0Akiln and then =3D0A> proceeded with the firing?=3D0A=3D0AMan=
y thanks=3D
.=3D0A=3D0ADeb Thuman=3D0A> href=3D3D"http://debthumansblog.blogspot.com/" =
target=3D
=3D3D_blank =3D0A> >http://debthumansblog.blogspot.com/=3D0A> href=3D3D"htt=
p://www.=3D
etsy.com/shop.php?user_id=3D3D5888059" target=3D3D_blank =3D0A> >http://www=
.etsy.=3D
com/shop.php?user_id=3D3D5888059=3D0A> href=3D3D"http://www.facebook.com/pa=
ges/De=3D
b-Thumans-Art-Page/167529715986" =3D0A> target=3D3D_blank =3D0A> >http://ww=
w.face=3D
book.com/pages/Deb-Thumans-Art-Page/167529715986=3D0A=3D0A=3D0A
William & Susan Schran User on mon 28 jun 10
On 6/28/10 12:26 PM, "Deborah Thuman" wrote:
> It's summer, temps are getting to upper 90's and low 100's. How
> necessary is it to candle a gas kiln overnight in this weather? For
> those who fire gas in the southwest during the summer.... do you
> candle? For how long?
>
> Would it damage my work or the kiln if I started with a low flame, and
> raised the flame bit by bit until I got a red glow from inside the
> kiln and then proceeded with the firing?
I never candle gas kilns, think it's a waste of time and energy.
Gas kiln at school - start with all burners on "low", slowly turning up the
gas pressure. After couple hours we're near 1000F. Never had anything blow
up - that happens in the bisque firing due to moisture content.
Bill
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
Dale Neese on mon 28 jun 10
Hey Debra,
I have an Olsen 24 and I never have kept the kiln on low over night. Severa=
l
reasons for this is by the time I've loaded everything in the kiln the
pieces are dried to the point that I don't need to candle to dry off the
moisture. I glaze work and put them back on a shelf in the studio to dry or
load into the kiln for lack of shelf space. Last pieces I glaze are put out
in the summer sun in South Texas to dry before loading and can reach cone
022 all by themselves!!
Usually I turn the first set of burners on very low for 2 hours before
turning the kiln up to an inch of water column and that's all it takes
sometimes. Hold a mirror up to the top peep. If it fogs up then let the kil=
n
go longer until the lack of moisture doesn't fog the mirror up.
I've never have been in much of a hurry to fire any kiln load. Haste makes
waste. Some people will candle over night to drive off the moisture because
they've put freshly glazed pieces in but also to cut down on the firing tim=
e
the next day because they don't want to manage the firing for a long time.
That's all I can figure out. Hard brick kilns are notorious for taking a
long time just to absorb heat so then candling over night does make sense. =
I
don't think I can sleep soundly knowing that my gas kiln is on overnight. I
have to be there with the kiln to know what's going on if something should
happen that I didn't expect. And believe me it will happen.
Dale Tex
"across the alley from the Alamo"
Helotes, Texas USA
www.daleneese.com
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Snail Scott on tue 29 jun 10
On Jun 28, 2010, at 3:33 PM, Craig Martell wrote:
> I don't think it's necessary to candle a kiln at all... I start the
> fire by warming for a
> half hour with the pilot burners. Then I lite the Buzzers and give
> them just enough gas to stay lit with a gentle flame...
How is this not candling?
I would say that the time you spend with
the kiln below 200F then gradually raising
the temperature past the steam-explosion
temperature range is candling, whether it
is done as a separate phase of firing or just
a slow continuous ramp, and regardless of
the time it takes. A ten-minute candling is
still candling, even if the temp eventually
rises past the danger zone with no deliberate
adjustments.
-Snail
Snail Scott on tue 29 jun 10
On Jun 28, 2010, at 4:54 PM, KATHI LESUEUR wrote:
> I never candle my gas kiln. I have four forced air burners. I turn on
> the bottom two very low, and with out the air turned on (they act
> like a venturi) until the kiln is at about 800 degrees...
I would call this candling. How are we
defining this term?
-Snail
Lee Love on wed 30 jun 10
A couple times, with my wood kiln, I lit a fire the night before, got
it up to about 200 or 300*F, and then closed the kiln up. Part of my
load was always single fire and some of the work was not bone dry.
Everything would be bone dry by the morning.
--
Lee, a Mashiko potter in Minneapolis
http://mingeisota.blogspot.com/
=3D93Observe the wonders as they occur around you. Don't claim them. Feel
the artistry moving through and be silent.=3D94 --Rumi
Clyde Tullis on thu 1 jul 10
I always thought that candling was what ever you did at the beginning of =
=3D
the
cycle to drive the water out.
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