interest in small gas kilns?

updated tue 8 aug 06

Hank Murrow on wed 2 aug 06

On Aug 2, 2006, at 4:10 PM, William & Susan Schran User wrote:

> A recent conversation with a kiln manufacturer turned to the question
> of
> interest of potters in small gas fired kilns.
>
> We are talking about a 7 cu. Ft. updraft kiln.
> There are manufacturers currently building these kilns, but their
> reputation
> ain't all that great - and I can attest to that!
>
> But what about a kiln built by a reputable manufacturer, that will
> stand
> behind their product and offer good technical support?
> A kiln that has been carefully engineered and tested?
>
> I would think such a kiln would also be accompanied by quality exhaust
> venting system and perhaps a gas certification certificate.
>
> But is this the right size gas fired kiln for most part-time potters?
> I'm sure most folks making their living from pottery would have need
> of a
> larger kiln or would rather build their own.
>
> What about price?
> What would you be willing to pay for a such a piece of equipment?

Hank replies;

Good idea! Something for electric firers to move into but not too big a
step, and not too expensive. Jim Laub (who fabricates my Doorless Fiber
Kiln) and I have been working on a small (8 cuft) downdraft
soda/reduction/oxidation kiln which lifts like my larger (27 cuft)
Doorless Fiber Kiln, but exhausts out the floor for more even heat and
vapor distribution. So far, we think it can come in at around $8000, or
twice what a similar size cone 10 electric would cost. The innovation
lies in both the lifting design (with all burners, ports, flue
connections, etc) in the base, and a fiber-lined bell which could be
interchangeable with a bell designed to do alternate fires......say
cone 10 pullouts. Think of a firing pad that can accommodate one or
more bells which hang on the wall. So one could fire many different
types of firing with one small kiln, changing only the bell. The base
will be 2" of Silicon-carbide re-inforced castable user-replaceable
panels, backed up with 4" of ceramic fiber. The panels will be cast
into formica-clad molds so there will be no 'tooth' on the hot face on
which glaze could form.

We hope to have one firing sometime this fall to test the concept. My
27 cu ft Doorless Fiber Kiln fires for around $24, so it seems
reasonable that the 8 cu ft kiln should fire for around $12_$15 of
natural gas or propane. Anyway, we are excited but cautious.

Cheers, Hank
www.murrow.biz/hank

William & Susan Schran User on wed 2 aug 06

A recent conversation with a kiln manufacturer turned to the question of
interest of potters in small gas fired kilns.

We are talking about a 7 cu. Ft. updraft kiln.
There are manufacturers currently building these kilns, but their reputation
ain't all that great - and I can attest to that!

But what about a kiln built by a reputable manufacturer, that will stand
behind their product and offer good technical support?
A kiln that has been carefully engineered and tested?

I would think such a kiln would also be accompanied by quality exhaust
venting system and perhaps a gas certification certificate.

But is this the right size gas fired kiln for most part-time potters?
I'm sure most folks making their living from pottery would have need of a
larger kiln or would rather build their own.

What about price?
What would you be willing to pay for a such a piece of equipment?

No idea if responses might lead to anything or not.


-- William "Bill" Schran
Fredericksburg, Virginia
wschran@cox.net
wschran@nvcc.edu

Ben Shelton on thu 3 aug 06

I'm not in the market but

just pricing the cost of materials for a kiln of that relative size

$750 for a burner system from Ward
$600 or so for 2 layers of 2600 degree brick
$300 for welding and hardware

about $1650 for material costs easy

plus labor
plus profit


Sounds like a $2500 kiln to me. Give or take for the size of course.

These prices reflect buying one time quantities of off the shelf priced items.

I don't know how much cheaper you might get the parts if you bought in quantity.

Ben

Overall's on thu 3 aug 06

I don't know that much about kiln design, but I DO
have experience in firing a 7 cu.ft. updraft.

A better design for this small kiln to me would be
have one big burner coming in from the bottom side,
maybe at an angle for "swirling" flames to even temp.
instead of underneath the thing. That way the burner
port can actually be closed off to prevent
re-oxidation when it's time to shutterdown. It will
also allow for more control of the firing atmosphere.

I practically have to stand on my head upside down to
fire this kiln in reduction. I won't go into
particulars, but it's ridiculous. Kiln was affordable
and there. Would I buy another like it? NOT for high
fire reduction. Raku yes.

Kim in Houston
http://www.houstonpotters.com


--- William & Susan Schran User
wrote:

> A recent conversation with a kiln manufacturer
> turned to the question of
> interest of potters in small gas fired kilns.
>
> We are talking about a 7 cu. Ft. updraft kiln.
> There are manufacturers currently building these
> kilns, but their reputation
> ain't all that great - and I can attest to that!
>
> But what about a kiln built by a reputable
> manufacturer, that will stand
> behind their product and offer good technical
> support?
> A kiln that has been carefully engineered and
> tested?
>
> I would think such a kiln would also be accompanied
> by quality exhaust
> venting system and perhaps a gas certification
> certificate.
>
> But is this the right size gas fired kiln for most
> part-time potters?
> I'm sure most folks making their living from pottery
> would have need of a
> larger kiln or would rather build their own.
>
> What about price?
> What would you be willing to pay for a such a piece
> of equipment?
>
> No idea if responses might lead to anything or not.
>
>
> -- William "Bill" Schran
> Fredericksburg, Virginia
> wschran@cox.net
> wschran@nvcc.edu
>
>
______________________________________________________________________________
> 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.
>



http://www.houstonpotters.com

William & Susan Schran User on thu 3 aug 06

On 8/3/06 7:57 AM, "Overall's" wrote:

> I practically have to stand on my head upside down to
> fire this kiln in reduction. I won't go into
> particulars, but it's ridiculous. Kiln was affordable
> and there. Would I buy another like it? NOT for high
> fire reduction. Raku yes.

Kim,

I assume you have an Olympic updraft, as do I.

I have found I can get fairly good reduction results by:

1. Setting the primary air opening (disks on back of burners) to about 1/4"
open and leaving them there all the time.
FYI - I don't have the original burners. I replaced the pipe burners with
MR-750 Venturi burners - work better at low pressures.

2. Leave gas pressure low the entire firing.

3. Control reduction & temperature top to bottom with two insulating
firebricks as the dampers at the flue opening.

Hope this helps.


-- William "Bill" Schran
Fredericksburg, Virginia
wschran@cox.net
wschran@nvcc.edu

Bruce Girrell on thu 3 aug 06

Ben Shelton wrote:

>$600 or so for 2 layers of 2600 degree brick

I come up with about 500 _bricks_ . Multiply by the current cost of IFB in
your neighborhood. Better at least double that $600 figure

One form of a 7 cu ft kiln would be 24" x 18" x 25" (3 bricks x 2 bricks x
10 courses). When you include the bricks required to make a 9" wall you end
up with 28 bricks per course (the door bricks are included) or 280 bricks
for the walls. The floor requires 40 bricks per course and three courses
gives you a 7 1/2" thick floor, so we need an additional 120 bricks for the
floor. I'm just guessing the arch, but since each floor course requires 40
bricks, it's not out of line to say that we'll need 100 bricks for the arch.
That comes up to 280 + 120 + 100 = 500 bricks

It always appalls me to see the number of bricks required for even a small
project.

My next area of concern would be the burners. For such a small kiln,
especially an updraft, you won't get good flame distribution using burners
like the MR-750. You'll need a larger number of smaller burners to
distribute the heat more evenly. I am using two Ransome B-3 burners on an 18
cu ft updraft and I have to keep them throttled back to 3 psi, even for cone
10. I would have done much better to go with four B-2s or perhaps six B-1
burners.

Don't forget the BASOs. They're not cheap.

When you look at catalogs or call for prices for a manufactured kiln you can
be left with a severe case of sticker shock. But when you start adding up
all the costs, it turns out that the manufacturers are putting products out
there at pretty reasonable prices.

Bruce "numbers ? us" Girrell

Norman Aufrichtig on thu 3 aug 06

hi hank,
curious, what height ceiling would be needed for the kiln?
normana
----- Original Message -----
From: "Hank Murrow"
To:
Sent: Wednesday, August 02, 2006 11:24 PM
Subject: Re: [CLAYART] Interest in small gas kilns?


> On Aug 2, 2006, at 4:10 PM, William & Susan Schran User wrote:
>
> > A recent conversation with a kiln manufacturer turned to the question
> > of
> > interest of potters in small gas fired kilns.
> >
> > We are talking about a 7 cu. Ft. updraft kiln.
> > There are manufacturers currently building these kilns, but their
> > reputation
> > ain't all that great - and I can attest to that!
> >
> > But what about a kiln built by a reputable manufacturer, that will
> > stand
> > behind their product and offer good technical support?
> > A kiln that has been carefully engineered and tested?
> >
> > I would think such a kiln would also be accompanied by quality exhaust
> > venting system and perhaps a gas certification certificate.
> >
> > But is this the right size gas fired kiln for most part-time potters?
> > I'm sure most folks making their living from pottery would have need
> > of a
> > larger kiln or would rather build their own.
> >
> > What about price?
> > What would you be willing to pay for a such a piece of equipment?
>
> Hank replies;
>
> Good idea! Something for electric firers to move into but not too big a
> step, and not too expensive. Jim Laub (who fabricates my Doorless Fiber
> Kiln) and I have been working on a small (8 cuft) downdraft
> soda/reduction/oxidation kiln which lifts like my larger (27 cuft)
> Doorless Fiber Kiln, but exhausts out the floor for more even heat and
> vapor distribution. So far, we think it can come in at around $8000, or
> twice what a similar size cone 10 electric would cost. The innovation
> lies in both the lifting design (with all burners, ports, flue
> connections, etc) in the base, and a fiber-lined bell which could be
> interchangeable with a bell designed to do alternate fires......say
> cone 10 pullouts. Think of a firing pad that can accommodate one or
> more bells which hang on the wall. So one could fire many different
> types of firing with one small kiln, changing only the bell. The base
> will be 2" of Silicon-carbide re-inforced castable user-replaceable
> panels, backed up with 4" of ceramic fiber. The panels will be cast
> into formica-clad molds so there will be no 'tooth' on the hot face on
> which glaze could form.
>
> We hope to have one firing sometime this fall to test the concept. My
> 27 cu ft Doorless Fiber Kiln fires for around $24, so it seems
> reasonable that the 8 cu ft kiln should fire for around $12_$15 of
> natural gas or propane. Anyway, we are excited but cautious.
>
> Cheers, Hank
> www.murrow.biz/hank
>
>
____________________________________________________________________________
__
> 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.
>
>
>
> --
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>



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Frank Colson on thu 3 aug 06

Ben- Ward is a very good and reliable burnner supplier, but I could knock
the $750 burnner system down to $50.00 ,for a system to fire same size gas
kiln with my design buners!
After all, its the results your after, right? Does it really matter on the
kind of system installed as to the kind of pots that happen? So, it looks
like a $1,750.00 kiln cost , indeed!

Frank Colson
www.R2D2u.com
----- Original Message -----
From: "Ben Shelton"
To:
Sent: Thursday, August 03, 2006 3:57 AM
Subject: Re: Interest in small gas kilns?


> I'm not in the market but
>
> just pricing the cost of materials for a kiln of that relative size
>
> $750 for a burner system from Ward
> $600 or so for 2 layers of 2600 degree brick
> $300 for welding and hardware
>
> about $1650 for material costs easy
>
> plus labor
> plus profit
>
>
> Sounds like a $2500 kiln to me. Give or take for the size of course.
>
> These prices reflect buying one time quantities of off the shelf priced
> items.
>
> I don't know how much cheaper you might get the parts if you bought in
> quantity.
>
> Ben
>
> ______________________________________________________________________________
> 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.
>

Frank Colson on thu 3 aug 06

Bill- This is just a suggestion, but I can provide you with an illustrated
working eBook for building a sweet 12'cu.ft. updraft gas kiln plans which
just won't stop making you happy with consistant firings up and over cone
ten! For sure you would have it for considerably less cost than purchasing
a manufactured one. And the best part is, since you will build it, you will
know it inside out, plus have my personal assitance in operationl help from
now to forever! That will get you operational, part time, full time, iand
nbetween time with the best pots you ever made! Just go to the following
website: www.R2D2u.com and click on CATERINA CATENARY!

Frank Colson
www.R2D2u.com
----- Original Message -----
From: "William & Susan Schran User"
To:
Sent: Wednesday, August 02, 2006 4:10 PM
Subject: Interest in small gas kilns?


>A recent conversation with a kiln manufacturer turned to the question of
> interest of potters in small gas fired kilns.
>
> We are talking about a 7 cu. Ft. updraft kiln.
> There are manufacturers currently building these kilns, but their
> reputation
> ain't all that great - and I can attest to that!
>
> But what about a kiln built by a reputable manufacturer, that will stand
> behind their product and offer good technical support?
> A kiln that has been carefully engineered and tested?
>
> I would think such a kiln would also be accompanied by quality exhaust
> venting system and perhaps a gas certification certificate.
>
> But is this the right size gas fired kiln for most part-time potters?
> I'm sure most folks making their living from pottery would have need of a
> larger kiln or would rather build their own.
>
> What about price?
> What would you be willing to pay for a such a piece of equipment?
>
> No idea if responses might lead to anything or not.
>
>
> -- William "Bill" Schran
> Fredericksburg, Virginia
> wschran@cox.net
> wschran@nvcc.edu
>
> ______________________________________________________________________________
> 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.
>

Hank Murrow on thu 3 aug 06

On Aug 3, 2006, at 9:23 AM, Norman Aufrichtig wrote:

> hi hank,
> curious, what height ceiling would be needed for the kiln?

Well, we think around 7"5", but won't really know until we build it. As
with architecture, drawings are unreliable to some extent.

Cheers, Hank

Ivor and Olive Lewis on fri 4 aug 06

Dear Frank Colson,

Sounds like a good deal <<...I could knock the $750 burnner system down =
to $50.00 ,for a system to fire same size gas kiln with my design =
buners!....>>=20

I take it you give a copper bottomed, cast iron, twenty four karat =
guarantee regarding safety issues. You would unequivocally indemnify any =
user of your design against all eventualities ?

I have a little more respect for Gas Fired Systems.

Best regards,

Ivor Lewis.
Redhill,
South Australia.

William & Susan Schran User on fri 4 aug 06

On 8/3/06 3:26 PM, "Frank Colson" wrote:

> I could knock
> the $750 burnner system down to $50.00 ,for a system to fire same size gas
> kiln with my design buners!

Frank,
I assume you are writing about pipe burners.

This type of burner came with the Olympic updraft I have.

After a few firings and issues with back burning at low pressure settings, I
pulled those things out and replaced them with MR-750 Venturi burners.
I've not had any problems with these, no matter how low the pressure.


-- William "Bill" Schran
Fredericksburg, Virginia
wschran@cox.net
wschran@nvcc.edu

Maggie Woodhead on fri 4 aug 06

Kia Ora Clayarters,
Seeing this email about gas kilns here is
the kiln built by Derek the year I went to NCECA in Denver. It is gas and
7.5 cub ft stacking but brilliant to fire. Very even and as fast to fire as
I would need it to be. Controllable! Love it to bits! I fire to cone 9 -
10 in between 6 to 8 hours depending on what glaze results I want and often
strike fire to get the copper reds.
Tricky, but my favourite glaze and also that of my family.
I got this email from my sent file but some of you may not have seen it and
we have a new url as follows.
http://homepages.slingshot.co.nz/~derek.woodhead/NewKiln/IndexNewKiln.html

Built by my husband who is the kind of fellow who is clever with his hands
(and brain of course). Cost about $1500 US, made from stuff from the tip
and old gear around the house plus a lot of expertise and reading the books
by Nils Lou and one or two other Clayart experts.
Kiln Photos Regards and Best wishes Maggie
maggie.w@paradise.net.nz

" Interest in small gas kilns?"
interest of potters in small gas fired kilns. We are talking about a 7 cu.
Ft. updraft kiln.
But what about a kiln built by a reputable manufacturer, that will stand
behind their product and offer good technical support?
A kiln that has been carefully engineered and tested?>

But is this the right size gas fired kiln for most part-time potters?
I'm sure most folks making their living from pottery would have need of a
larger kiln or would rather build their own.

What about price?
What would you be willing to pay for a such a piece of equipment?

No idea if responses might lead to anything or not.



______________________________________________________________________________
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.