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gas kiln glaze firing schedule

updated tue 1 feb 11

 

Gary Beckwith on sun 30 jan 11


Hi all,

I picked up a gas kiln a while ago and have had it in storage. It's an
old Thermolite kiln. It has 4 MR750 burners. It was set up originally
for natural gas, but I plan to run it on propane. The interior
dimensions are 28" x 30".

I have no experience firing a gas kiln (except for my oil drum raku
kiln), so was hoping someone could help me with a firing schedule/temp
ramp-up/soak times. I'm using cone 5 commercial groggy clays, primarily
B-Mix and Laguna RSMC or RedStone. For glazes, also commercial, mostly
Coyote or Amaco Potters Choice cone 5/6 glazes. My ware is medium to
large size thrown ware.

I just need a suggested firing schedule for Cone 5/6 glaze, something I
could at least start out with and modify as needed.

Thanks!
Gary Beckwith
Auburn, CA

Larry Kruzan on sun 30 jan 11


Hi Gary,

Here's one that I use;

1. 0-1100 400 degrees hr Hold 1/2 hr
2. 1100-1750 300 degree per hours
3. Start reduction - Med for half hour
4. Lighten reduction until temp starts to climb - 200 degrees per hr to
2000 2000-2180 100 degrees per hour 5. Half hour hold at 2180 oxidized

At this point you could shut the kiln down but I choose to down fire by
slowly reducing the gas to drop the temp at 100-150 per hour to 1800 at
which point I shutdown.

I don't plat with the damper a lot having found it's "sweet spot". If you
have a oxyprobe it will be much easier to "read" what's going on and be as
fuel efficient as possible.

Where are you located? Perhaps there is an experienced clayarter that can d=
o
a little "hand holding" on a firing.

Larry Kruzan
Lost Creek Pottery
www.lostcreekpottery.com

-----Original Message-----
From: Clayart [mailto:Clayart@LSV.CERAMICS.ORG] On Behalf Of Gary Beckwith
Sent: Sunday, January 30, 2011 10:56 AM
To: Clayart@LSV.CERAMICS.ORG
Subject: Gas Kiln Glaze Firing Schedule

Hi all,

I picked up a gas kiln a while ago and have had it in storage. It's an
old Thermolite kiln. It has 4 MR750 burners. It was set up originally
for natural gas, but I plan to run it on propane. The interior
dimensions are 28" x 30".

I have no experience firing a gas kiln (except for my oil drum raku
kiln), so was hoping someone could help me with a firing schedule/temp
ramp-up/soak times. I'm using cone 5 commercial groggy clays, primarily
B-Mix and Laguna RSMC or RedStone. For glazes, also commercial, mostly
Coyote or Amaco Potters Choice cone 5/6 glazes. My ware is medium to
large size thrown ware.

I just need a suggested firing schedule for Cone 5/6 glaze, something I
could at least start out with and modify as needed.

Thanks!
Gary Beckwith
Auburn, CA

William & Susan Schran User on sun 30 jan 11


On 1/30/11 11:55 AM, "Gary Beckwith" wrote:

> I have no experience firing a gas kiln (except for my oil drum raku
> kiln), so was hoping someone could help me with a firing schedule/temp
> ramp-up/soak times. I'm using cone 5 commercial groggy clays, primarily
> B-Mix and Laguna RSMC or RedStone. For glazes, also commercial, mostly
> Coyote or Amaco Potters Choice cone 5/6 glazes. My ware is medium to
> large size thrown ware.

Gary,
Is this an updraft or downdraft kiln?
If it ran on natural gas you will need to change burner orifices to fire
with propane.
Suggest you contact Marc Ward at Ward Burner so you can discuss your plans.
He'll help with proper orifice size, proper gas line size, pressure gauges,
etc.

I would suggest you fire the kiln loaded with kiln furniture only the first
time, using cones top, middle, bottom - front and back to get a good sense
of how the kiln fires.

Bill

--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com

Gary Beckwith on sun 30 jan 11


Actually I got in contact with Mark Ward when I first got the kiln, and
had ordered the correct propane orifices for it. So I already have
them. I contacted him again last week and ordered the right hoses,
regulator, etc. for the tanks that I'm using so I should be ready to
fire. It's updraft, top loading.

I like your suggestion of firing it with everything but the wares the
first time. I will definitely do that. Thanks!

Thanks,
Gary



> Gary,
> Is this an updraft or downdraft kiln?
> If it ran on natural gas you will need to change burner orifices to fire
> with propane.
> Suggest you contact Marc Ward at Ward Burner so you can discuss your plan=
s.
> He'll help with proper orifice size, proper gas line size, pressure gauge=
s,
> etc.
>
> I would suggest you fire the kiln loaded with kiln furniture only the fir=
st
> time, using cones top, middle, bottom - front and back to get a good sens=
e
> of how the kiln fires.
>
> Bill
>

Steve Mills on mon 31 jan 11


My current Gas Kiln was designed to run on Natural Gas which here in the UK=
i=3D
s piped in at 10" of water pressure.=3D20
All I have done to convert to propane is install a pressure reducing regula=
t=3D
or rated to 50mb in line.=3D20
A whole lot cheaper than changing burner jets et al!

Steve M

Steve Mills
Bath
UK
www.mudslinger.me.uk
Sent from my Ipod touch

On 31 Jan 2011, at 03:06, William & Susan Schran User wro=
t=3D
e:

> On 1/30/11 11:55 AM, "Gary Beckwith" wrote:
>=3D20
>> I have no experience firing a gas kiln (except for my oil drum raku
>> kiln), so was hoping someone could help me with a firing schedule/temp
>> ramp-up/soak times. I'm using cone 5 commercial groggy clays, primarily
>> B-Mix and Laguna RSMC or RedStone. For glazes, also commercial, mostly
>> Coyote or Amaco Potters Choice cone 5/6 glazes. My ware is medium to
>> large size thrown ware.
>=3D20
> Gary,
> Is this an updraft or downdraft kiln?
> If it ran on natural gas you will need to change burner orifices to fire
> with propane.
> Suggest you contact Marc Ward at Ward Burner so you can discuss your plan=
s=3D
.
> He'll help with proper orifice size, proper gas line size, pressure gauge=
s=3D
,
> etc.
>=3D20
> I would suggest you fire the kiln loaded with kiln furniture only the fir=
s=3D
t
> time, using cones top, middle, bottom - front and back to get a good sens=
e=3D

> of how the kiln fires.
>=3D20
> Bill
>=3D20
> --
> William "Bill" Schran
> wschran@cox.net
> wschran@nvcc.edu
> http://www.creativecreekartisans.com