Dan Hill on fri 31 dec 10
Happy 2011 everyone.
I have a couple of old electrics I plan to convert to propane this spring,
they are in the 7-8 cu. ft. range. One will be an undraft for ^6 soda and
the other I thought I would try as a downdraft for ^6 reduction. I can see
how a kiln like this would be great for all those potters out there that
don't have access to a gas kiln but long for the fire.
My question is about burners. There are many options from weed burners as i=
n
Simon Leach's videos to venturis and the Nils liquid propane burners. I am
not sure how Simon gets reduction control with the weed burner. Axner also
has several conversion burner kits that mount under the kiln.
If anyone has experience with a burner setup that works or one that did not
I would appreciate the info.
I will post my successes and failures with this project to the list.
Dan Hill
Hill Pottery
^6 soda fired porcelain and stoneware
Vince Pitelka on fri 31 dec 10
Dan Hill wrote:
I have a couple of old electrics I plan to convert to propane this spring,
they are in the 7-8 cu. ft. range. One will be an undraft for ^6 soda and
the other I thought I would try as a downdraft for ^6 reduction. I can see
how a kiln like this would be great for all those potters out there that
don't have access to a gas kiln but long for the fire. My question is abou=
t
burners. There are many options from weed burners as in Simon Leach's video=
s
to venturis and the Nils liquid propane burners. I am not sure how Simon
gets reduction control with the weed burner. Axner also has several
conversion burner kits that mount under the kiln. If anyone has experience
with a burner setup that works or one that did not I would appreciate the
info.
Hi Dan -
I think this is a great way to go. Of course the softbrick will deteriorat=
e
from the soda, but if you spray on a very fluid coat of ITC-100 or a
homemade refractory coating (wet enough to really soak into the brick,
including in the element grooves) you can get good life out of it, and of
course when the bricks start to die, you can just throw away the kiln and
install another dead electric on the same burner system. That's a great wa=
y
to get a cheap soda kiln. I checked out the systems available from Olympic
and Axner, and I like the looks of the Summit GV-24 Conversion Kit at
http://www.axner.com/summitgv-24conversionkitshipsmfg.aspx. As near as I
can tell from the small photo, they are using the GACO MR-750 burners, and
the Summit system for the 7-cubic-foot toploaders includes four burners,
which should give plenty of power for cone-10 firing. I do not know how
Summit is able to put this kit together with four burners, a gas valve, and
all the plumbing and framework and still sell it for $295. Just the four
MR-750s would cost $200 by themselves, so a person would not save any money
at all by building this unit themselves if they place any value on their ow=
n
labor. It is important to note that if you want the system equipped with a
BASO valve it will cost an additional $230, and I would certainly recommend
that.
- Vince
Vince Pitelka
Appalachian Center for Craft
Tennessee Tech University
vpitelka@dtccom.net; wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka
William & Susan Schran User on fri 31 dec 10
On 12/31/10 11:36 AM, "Vince Pitelka" wrote:
> I checked out the systems available from Olympic
> and Axner, and I like the looks of the Summit GV-24 Conversion Kit at
> http://www.axner.com/summitgv-24conversionkitshipsmfg.aspx. As near as I
> can tell from the small photo, they are using the GACO MR-750 burners, an=
d
> the Summit system for the 7-cubic-foot toploaders includes four burners,
> which should give plenty of power for cone-10 firing. I do not know how
> Summit is able to put this kit together with four burners, a gas valve, a=
nd
> all the plumbing and framework and still sell it for $295.
Bought similar set up from Summit years ago.
Burners, etc. are similar to Olympic up drafts, which are pipe burners.
The Axner/Summit burners, from what I recall as I no longer have this kiln
(think DW has it now) are two piece pipe, not true venturi and did not have
primary air disks on back of burner. It is inexpensive because of the
components - what I might expect a kiln from Harbor Freight might be.
I suppose reduction is controlled only by gas pressure and damper setting.
Bill
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
Vince Pitelka on fri 31 dec 10
Bill Schran wrote:
Bought similar set up from Summit years ago. Burners, etc. are similar to
Olympic up drafts, which are pipe burners. The Axner/Summit burners, from
what I recall as I no longer have this kiln (think DW has it now) are two
piece pipe, not true venturi and did not have primary air disks on back of
burner. It is inexpensive because of the components - what I might expect a
kiln from Harbor Freight might be. I suppose reduction is controlled only b=
y
gas pressure and damper setting.
Hi Bill -
Yes, that does make it clear how Summit is able to sell the system so cheap=
.
That's too bad, because I was hoping that they were using the MR-750. Give=
n
that information, I personally would elect to build my own system using the
MR-750, available from Ward Burner and other suppliers. Does anyone know o=
f
a conversion system available that uses this burner? I am CC'ing this to
Marc Ward, because if he doesn't already offer such a kit, it would be a
great addition to his product line. It has become such a popular thing to d=
o
- converting an old electric toploader to gas.
I should mention that at the Craft Center we have an old Norman updraft gas
frontloader kiln that has small venturis with ceramic tubes and no primary
air shutter (disk) on the back end of the burner. They are well-designed
little burners, and it is no problem regulating oxidation/reduction with ga=
s
pressure and damper setting with no primary air adjustment. It has always
been my theory that once the primary air shutters are properly set on a
natural draft burner, they are best left alone. Ideally, changes in damper
setting and gas pressure will affect both primary and secondary air, and
adjustments between oxidation and reduction can be accommodated without a
primary air adjustment. So ideally, if you have a venturi with no primary
air shutter that still works properly, it shouldn't be an issue. But
personally, I do like to have such things within my own control, and would
prefer to have that primary air shutter.
Those pipe burners on the Olympic base look pretty crude, and I am
suspicious of the efficiency of any tube or venturi made from off-the-shelf
pipe fittings. They are okay in a pinch, and lots of us made do with
homemade pipe burners back when gas was cheap and the concept of exhausting
the world petroleum reserves was unimaginable. But there's no way that the=
y
can be as efficient as a true venturi designed by an experienced potter or =
a
combustion engineer, and it is pretty much a matter of responsibility and
good sense for us to use the most efficient burners possible.
- Vince
Vince Pitelka
Appalachian Center for Craft
Tennessee Tech University
vpitelka@dtccom.net; wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka
Tom Gordon on fri 31 dec 10
Dan,
I purchased the two burner version of the Summit conversion kit that Vince
referred to.
The fine folks at Axners actually gave me a phone number to call Summit
directly and order from.
The "kit" includes templates of where to cut the holes in the bottom of the
kiln for the burners and a template for where to cut the hole in the top
of the kiln. It took about 45 mins to make the conversion... and only
because I was being paranoid careful (you could probably do it in about 15=
mins
but hey enjoy the process!).
I am very happy with the product though after about 50 firings I would
prefer an independent control for each burner (which they would probably do=
for
you at extra cost). With just pilot lights going I am getting to about
600 degrees F. It is a very high quality operation and they deliver on tim=
e.
It does take a certain "nack" with the ball valve, watch your ramp rates,
if a rookie like me can figure it out then I'm sure you won't have a
problem. During windy days I stack cinder blocks around the outside of the =
base
to deflect the wind. It was interesting getting used to shutting things
down after using only electric kilns (learning to lower temps instead of j=
ust
shutting things off).
Hope this helps!
Tom Gordon
In a message dated 12/31/2010 12:16:53 P.M. Eastern Standard Time,
vpitelka@DTCCOM.NET writes:
Dan Hill wrote:
I have a couple of old electrics I plan to convert to propane this spring,
they are in the 7-8 cu. ft. range
William & Susan Schran User on wed 5 jan 11
On 1/5/11 1:41 PM, "Cathi Newlin" wrote:
> I'm wondering what the issues are with the Summit burners?
At the start of this thread I responded to Vince that I had gotten the
Summit conversion many years ago. The burners are simple pipe burners with
no primary air disks on the back of the burners. They are not as efficient
or powerful as the same size true venturi burners.
Bill
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
William & Susan Schran User on thu 6 jan 11
On 1/6/11 9:23 AM, "Rob Haugen" wrote:
> You may want to take a look at one of our current burner systems a little
> more carefully. I can assure you that our burners are not a conglomerati=
on
> of "off the shelf" parts. We use a GACO AM100 air mixer that most
> definitely do have a shutter plate for primary air adjustment. In fact t=
he
> shutter plate, brass spud and orifice are the same for the AM100 and the
> MR750. We have done extensive testing with our current burner and the MR=
750
> and find very little difference in performance between the two burners. =
We
> have been building gas kilns for over 40 years and have probably built mo=
re
> gas kilns than anyone out there. We are very aware of the gas kiln firin=
g
> process and we strive to build a simple kiln, that can be easily set up a=
nd
> fired by anybody with the desire to fire a gas kiln. If someone wants th=
e
> MR750's on one of our kilns, we can do it, but I do not feel that it is a
> necessity. If someone wants to buy just the burner system and do the
> conversion, we will do that as well.
Rob, Thank you for your input.
I note that you wrote: " We use a GACO AM100 air mixer that most
definitely do have a shutter plate for primary air adjustment. In fact th=
e
shutter plate, brass spud and orifice are the same for the AM100 and the
MR750." Dully noted.
I would ask: Why you don't use the complete MR750 burner on all of your
kilns? Why do you only use parts then attach a simple steel pipe? Is this
purely a cost issue?
I had one of your kilns, nearly brand new. Bought it from a fellow who fire=
d
it 3 times and could not get it to work for him. I set up the kiln, firing
with propane, with inline regulator to prevent over pressure on the baso
valve and encountered continuous back burning from the burners and build up
of carbon soot on bottom of kiln from the burner ignition tube. I called
Olympic, did all that was suggested, but with the same results.
I took it on myself to switch out the burners to MR750's (with added new
safety system), using the exact same gas pressure settings, and after makin=
g
some adjustments to interior loading configuration, I got the kiln to fire
very evenly with acceptable reduction. And I discovered I was using less ga=
s
than with the original burners.
This is my experience only, but I would ask that you seriously consider
using a true venturi burner for your gas fired kilns.
What I did to change the kiln can be found on my web site:
http://www.creativecreekartisans.com/creativecreek_upkiln.htm
Respectfully, Bill
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
Rob Haugen on thu 6 jan 11
Bill,
I knew that you would ask this question. Originally the Torchbearers were
designed with a burner from Charles A. Hones company. The burner was
discontinued and the AM100 was the burner that was most similar to the
original burner. The AM100 is a true venture burner. It has a shutter
plate, a cone shaped air mixer an exit pipe and a flame retention tip. We
could have gone either way with the burner, we chose the AM100 because it
was capable of 25,000 more BTU's. As far as your issues are concerned I ca=
n
only assume that the kiln was not set up properly. The most common problem=
s
that we experience with the Torchbearers are gas pressure that is too high
or incorrect shelves being used. The shelves for a torchbearer are 2 inches
smaller than a comparable electric kiln. We have added an air mixer to the
ignition system in order to introduce more air into the system. This has
greatly reduced the amount of carbon that builds up under the kiln. The
retention tips were added about 6 years ago after I read one of your posts
describing the issues that you have had with your kiln. It was at the same
time I did another comparison between the MR750 and the AM100, with the
addition of the retention tip I could not detect much difference. I can
promise you that if I felt that the MR750 was superior to the AM100, it
would be on the Torchbearer already.
Rob Haugen
Olympic Kilns
-----Original Message-----
From: William & Susan Schran User [mailto:wschran@cox.net]
Sent: Thursday, January 06, 2011 4:07 PM
To: Rob Haugen; Clayart@LSV.CERAMICS.ORG
Subject: Re: burners for electric kiln conversion
On 1/6/11 9:23 AM, "Rob Haugen" wrote:
> You may want to take a look at one of our current burner systems a little
> more carefully. I can assure you that our burners are not a
conglomeration
> of "off the shelf" parts. We use a GACO AM100 air mixer that most
> definitely do have a shutter plate for primary air adjustment. In fact
the
> shutter plate, brass spud and orifice are the same for the AM100 and the
> MR750. We have done extensive testing with our current burner and the
MR750
> and find very little difference in performance between the two burners.
We
> have been building gas kilns for over 40 years and have probably built
more
> gas kilns than anyone out there. We are very aware of the gas kiln firin=
g
> process and we strive to build a simple kiln, that can be easily set up
and
> fired by anybody with the desire to fire a gas kiln. If someone wants th=
e
> MR750's on one of our kilns, we can do it, but I do not feel that it is a
> necessity. If someone wants to buy just the burner system and do the
> conversion, we will do that as well.
Rob, Thank you for your input.
I note that you wrote: " We use a GACO AM100 air mixer that most
definitely do have a shutter plate for primary air adjustment. In fact th=
e
shutter plate, brass spud and orifice are the same for the AM100 and the
MR750." Dully noted.
I would ask: Why you don't use the complete MR750 burner on all of your
kilns? Why do you only use parts then attach a simple steel pipe? Is this
purely a cost issue?
I had one of your kilns, nearly brand new. Bought it from a fellow who fire=
d
it 3 times and could not get it to work for him. I set up the kiln, firing
with propane, with inline regulator to prevent over pressure on the baso
valve and encountered continuous back burning from the burners and build up
of carbon soot on bottom of kiln from the burner ignition tube. I called
Olympic, did all that was suggested, but with the same results.
I took it on myself to switch out the burners to MR750's (with added new
safety system), using the exact same gas pressure settings, and after makin=
g
some adjustments to interior loading configuration, I got the kiln to fire
very evenly with acceptable reduction. And I discovered I was using less ga=
s
than with the original burners.
This is my experience only, but I would ask that you seriously consider
using a true venturi burner for your gas fired kilns.
What I did to change the kiln can be found on my web site:
http://www.creativecreekartisans.com/creativecreek_upkiln.htm
Respectfully, Bill
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
William & Susan Schran User on thu 6 jan 11
Rob,
Thank you for sharing the information about the burners Olympic is currentl=
y
using in their kilns. I don't know if the original burners that were on the
kiln that I purchased 2nd hand were Hones or AM100's. As I recall, they had
a straight pipe with no changes at the end, no retention tip, so perhaps th=
e
older model.
On the kiln I had, I noted the original baso valve was stamped/labeled with
a limit of 1/2# pressure, so I had the propane guy installing my tank set
the inline regulator, before the valve, to that as the pressure limit. I
also got shelves that provided a 2" space between shelf and kiln wall.
With proper gas pressure and correct sized shelves, I still experienced
problems with the firings and specifically the burners. I can only assume,
if the kiln was equipped with AM100's perhaps I would not have had these
issues.
I am also glad to learn of improvements you have made to the ignition
system.
I recognize that you are producing an affordable product for the studio
potter. I also know for potters without much experience firing an updraft
kiln, or indeed any fuel fired kiln, the process can be quite a frustrating
experience. I didn't think the instructions that came with the kiln were
very helpful in troubleshooting. I hope you have listened to issues folks
have called about and rewritten the instructions in more detail. I would
like to suggest you produce a DVD, as other kiln manufacturers have done
that shows setting up the kiln, connecting gas lines and demonstrations of
firing the kiln. I truly believe your customers would appreciate such an
instructional video. I would hope that you would take all comments as
constructive criticism and use them to find ways to better serve your
customers. Having satisfied customers is the best advertising you can get.
Wishing you and Olympic success in the new year.
Bill
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
On 1/6/11 4:56 PM, "Rob Haugen" wrote:
> Bill,
> I knew that you would ask this question. Originally the Torchbearers wer=
e
> designed with a burner from Charles A. Hones company. The burner was
> discontinued and the AM100 was the burner that was most similar to the
> original burner. The AM100 is a true venture burner. It has a shutter
> plate, a cone shaped air mixer an exit pipe and a flame retention tip. W=
e
> could have gone either way with the burner, we chose the AM100 because it
> was capable of 25,000 more BTU's. As far as your issues are concerned I =
can
> only assume that the kiln was not set up properly. The most common probl=
ems
> that we experience with the Torchbearers are gas pressure that is too hig=
h
> or incorrect shelves being used. The shelves for a torchbearer are 2 inch=
es
> smaller than a comparable electric kiln. We have added an air mixer to t=
he
> ignition system in order to introduce more air into the system. This has
> greatly reduced the amount of carbon that builds up under the kiln. The
> retention tips were added about 6 years ago after I read one of your post=
s
> describing the issues that you have had with your kiln. It was at the sa=
me
> time I did another comparison between the MR750 and the AM100, with the
> addition of the retention tip I could not detect much difference. I can
> promise you that if I felt that the MR750 was superior to the AM100, it
> would be on the Torchbearer already.
>
> Rob Haugen
> Olympic Kilns
>
> -----Original Message-----
> From: William & Susan Schran User [mailto:wschran@cox.net]
> Sent: Thursday, January 06, 2011 4:07 PM
> To: Rob Haugen; Clayart@LSV.CERAMICS.ORG
> Subject: Re: burners for electric kiln conversion
>
> On 1/6/11 9:23 AM, "Rob Haugen" wrote:
>
>> You may want to take a look at one of our current burner systems a littl=
e
>> more carefully. I can assure you that our burners are not a
> conglomeration
>> of "off the shelf" parts. We use a GACO AM100 air mixer that most
>> definitely do have a shutter plate for primary air adjustment. In fact
> the
>> shutter plate, brass spud and orifice are the same for the AM100 and the
>> MR750. We have done extensive testing with our current burner and the
> MR750
>> and find very little difference in performance between the two burners.
> We
>> have been building gas kilns for over 40 years and have probably built
> more
>> gas kilns than anyone out there. We are very aware of the gas kiln firi=
ng
>> process and we strive to build a simple kiln, that can be easily set up
> and
>> fired by anybody with the desire to fire a gas kiln. If someone wants t=
he
>> MR750's on one of our kilns, we can do it, but I do not feel that it is =
a
>> necessity. If someone wants to buy just the burner system and do the
>> conversion, we will do that as well.
>
> Rob, Thank you for your input.
> I note that you wrote: " We use a GACO AM100 air mixer that most
> definitely do have a shutter plate for primary air adjustment. In fact =
the
> shutter plate, brass spud and orifice are the same for the AM100 and the
> MR750." Dully noted.
> I would ask: Why you don't use the complete MR750 burner on all of your
> kilns? Why do you only use parts then attach a simple steel pipe? Is this
> purely a cost issue?
>
> I had one of your kilns, nearly brand new. Bought it from a fellow who fi=
red
> it 3 times and could not get it to work for him. I set up the kiln, firin=
g
> with propane, with inline regulator to prevent over pressure on the baso
> valve and encountered continuous back burning from the burners and build =
up
> of carbon soot on bottom of kiln from the burner ignition tube. I called
> Olympic, did all that was suggested, but with the same results.
>
> I took it on myself to switch out the burners to MR750's (with added new
> safety system), using the exact same gas pressure settings, and after mak=
ing
> some adjustments to interior loading configuration, I got the kiln to fir=
e
> very evenly with acceptable reduction. And I discovered I was using less =
gas
> than with the original burners.
>
> This is my experience only, but I would ask that you seriously consider
> using a true venturi burner for your gas fired kilns.
>
> What I did to change the kiln can be found on my web site:
> http://www.creativecreekartisans.com/creativecreek_upkiln.htm
>
> Respectfully, Bill
>
> --
> William "Bill" Schran
> wschran@cox.net
> wschran@nvcc.edu
> http://www.creativecreekartisans.com
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