Mini Soda Kiln Conversion of Electric to Soda
#2
Posted 03 September 2012 - 12:13 AM
to the usual updraft style using propane and soda. I tested the concept with one that was only
2 cu ft but had more trouble with keeping the temperature steady and even. Maybe others
have experiences they can share, too, there's a lot of people with kiln experience here.
#7
Posted 03 September 2012 - 02:31 PM
best,
....................john
Immediate Past President; Potters Council
Professor of Ceramics; New Hampshire Insitute of Art
http://www.JohnBaymore.com
#8
Posted 03 September 2012 - 03:37 PM
#10
Posted 03 September 2012 - 05:28 PM
or ITC or a coating of slag resistant castable. You need a flu, chimney, burner ports, salt ports,etc. All you have is a rough start.
Marcia
#11
Posted 03 September 2012 - 11:10 PM
with propane (a barbecue tank) and a venturi (mk750 or similar small sized plain venturi),
a burner port is a hole cut into it [the side] and the chimney is a hole cut in the top. I run
mine as an updraft and have no problem controlling reduction. Although I don't
use any sort of oxygen monitor, I feel like I get oxidation when I need it, and
reduction is of course easy to get in a fuel kiln.
Adjusting the damper does more than affect the conditions for your glazes, it also
helps you use your fuel effectively.
Many people recommend placing a shelf inside the kiln just below the 'chimney'
hole to reflect heat back in, but I like to instead entirely cover the hole with part of a kiln shelf
supported on 1 inch posts around the kiln. I 'adjust the damper' by leaning firebricks
on it to partially block the effective opening. It's easy and works well to keep the top from
cooling too quickly. And you don't need to plan for extra posts on your top ware
shelf. As an added bonus, you have a number of warm bricks that
can be used to warm a water bath to keep the propane tank from chilling down too fast if you
are running the regulator at high pressure from a single 5 gallon tank.
I run my venturi up to 6psi (which I think is much higher than natural gas pressure)
and it is able to draw quite a lot of air.
You would probably be able to fire 4 cu ft to cone 10 on a single tank, but if you
go this route, I'd have a backup tank just in case.
A disadvantage of the propane torch setup I use is that the flame enters from the
side at the bottom and the first shelf is 4 - 5 inches above the kiln floor. Of course,
for a soda kiln, you can use this space to load your soda (I do this).
I am following Mark's (and others') advice to coat my brick to protect it, (colloidal
silica/zircon or ITC) but Laguna has been slow to fill my order for zircon recently
so I don't have direct experience with this.
I think you'll have a great time if you try it.
warmly,
Lily
#12
Posted 04 September 2012 - 07:10 AM
over ten years for firing raku at workshops and on my one kilns. Also make sure you have a regulator on the tank and a burner with the right BTU output.
Otherwise you could either wait for days trying hit hit temperature or you could send too much propane out the chimney.
For a soft brick well insulated kiln you need about 30,000 btu's /hour per cubic foot at ^10.
Marcia
#13
Posted 04 September 2012 - 02:18 PM
Thanks,
Stewart
LilyT, on 03 September 2012 - 11:10 PM, said:
with propane (a barbecue tank) and a venturi (mk750 or similar small sized plain venturi),
a burner port is a hole cut into it [the side] and the chimney is a hole cut in the top. I run
mine as an updraft and have no problem controlling reduction. Although I don't
use any sort of oxygen monitor, I feel like I get oxidation when I need it, and
reduction is of course easy to get in a fuel kiln.
Adjusting the damper does more than affect the conditions for your glazes, it also
helps you use your fuel effectively.
Many people recommend placing a shelf inside the kiln just below the 'chimney'
hole to reflect heat back in, but I like to instead entirely cover the hole with part of a kiln shelf
supported on 1 inch posts around the kiln. I 'adjust the damper' by leaning firebricks
on it to partially block the effective opening. It's easy and works well to keep the top from
cooling too quickly. And you don't need to plan for extra posts on your top ware
shelf. As an added bonus, you have a number of warm bricks that
can be used to warm a water bath to keep the propane tank from chilling down too fast if you
are running the regulator at high pressure from a single 5 gallon tank.
I run my venturi up to 6psi (which I think is much higher than natural gas pressure)
and it is able to draw quite a lot of air.
You would probably be able to fire 4 cu ft to cone 10 on a single tank, but if you
go this route, I'd have a backup tank just in case.
A disadvantage of the propane torch setup I use is that the flame enters from the
side at the bottom and the first shelf is 4 - 5 inches above the kiln floor. Of course,
for a soda kiln, you can use this space to load your soda (I do this).
I am following Mark's (and others') advice to coat my brick to protect it, (colloidal
silica/zircon or ITC) but Laguna has been slow to fill my order for zircon recently
so I don't have direct experience with this.
I think you'll have a great time if you try it.
warmly,
Lily
#14
Posted 04 September 2012 - 02:19 PM
Stewart
Marcia Selsor, on 04 September 2012 - 07:10 AM, said:
over ten years for firing raku at workshops and on my one kilns. Also make sure you have a regulator on the tank and a burner with the right BTU output.
Otherwise you could either wait for days trying hit hit temperature or you could send too much propane out the chimney.
For a soft brick well insulated kiln you need about 30,000 btu's /hour per cubic foot at ^10.
Marcia
#15
Posted 04 September 2012 - 03:44 PM
I have my burner port on the side of the kiln just above the floor, and
the flue/exit port is a hole cut into the lid of the kiln. I'm not actually
sure of the configuration of your Euclid, I'm thinking it's a standing
cylinder, so you can cut a hole there (drill to start, tin snips to cut, and
saw of series of drilled holes is one way to get through the shell layers)
I suppose you could try a chimney flue at the bottom of the kiln (and
you might need a stack in that case, though I'm not sure), but
I don't know that there's enough room for a bagwall in such a small kiln
and there could then be problems getting the top of the kiln to temp.
Does anyone reading this know?
Of course there's nothing to keep you from trying both, just save
any soft brick pieces and you can glue them back in (I like a mix of fireclay
and sawdust as brick 'glue'). In fact, don't forget to save the burner port
brick because you'll need to plug that up some way during the cool down.
Sorry, I noticed I was a little unclear in my original post about the kiln
shelf damper - it sits on the lid of the kiln in a top loading cylinder configuration.
Feel free to ask specific questions to clarify. I remember how nervous
I was before my first conversion, but once you do a couple, it's pretty
straightforward to get it working :-).
Marcia's idea of having a "Y" to connect two tanks so each has only
half the flow rate is the standard way to do it right - I was just cheap
and the connector and hose is expensive for my situation. Don't forget
that propane tubing needs to be checked frequently for weaknesses or
leaks, particularly if they are exposed to sunlight. The 5 gal bbq propane
tanks must always remain upright because otherwise liquid propane may
jet out the relief valve, causing a fire/explosion hazard. If you buy
used propane tanks meant for another use, be sure you know that you
are hooking your burner to the vapor and not the liquid output of the tank.
Putting liquid propane into a gas appliance is a good way to ruin
your day and lots of other stuff, to say the least.
You should have enough power with this setup to get your kiln to
cone 10 in well under 6 hours, but I wouldn't necessarily recommend it
unless you know what phase your clay/glaze is in.
-Lily
#16
Posted 04 September 2012 - 06:26 PM
On sprung arch kilns and car kilns I put the buners in the back so I don't bang them when loading. I like the drafte configuration of this as well, and built kilns using this system for 30+ years.
Marcia

Sign In
Register
Help










MultiQuote



