Mini Soda Kiln

[Stewart]

I have a small, electric Euclid's kiln and want your opinion on whether a conversion to a mini soda kiln would to feasible or even possible to achieve?

 

Not a lot of material out there about small conversions.

 

Thanks,

 

Stewart

 

[LilyT]

Probably :-). What size is the kiln? I've converted electric kilns of around 6 cubic feet in size

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.

[Mark C.]

Is this still going to use the elements for heating or are you thinking gas?

Mark

[Marcia Selsor]

I saw one made by Jason Briggs at the Appalachia Center for Crafts. He laid it side ways and used gas for fuel.

Marcia

[Stewart]

The kiln is about 4 cubic feet and I was planning on using gas.

[Mark C.]

Go for it I say-

Mark

[Guest JBaymore]

The IFB lining will be attacked by the soda... but you'll ge a number of firings out of it. If the unit was cheap... think of it as a cost of doing soda firing when if you did NOT do it.... you wouldn't be able to do.

 

best,

 

....................john

[LilyT]

The floor takes the brunt of the damage if you introduce soda in any way that drips or falls down. If you do that, I would take an old kiln shelf and line the entire floor or the appropriate areas, otw it will eat it's way through the soft brick rather rapidly.

[Mark C.]

You could coat it with the Zircon /colloidal silica recipe I posted a while back-this also will add life to it.

Mark

[Marcia Selsor]

Using the body of the kiln is one thing but you do need to do addtional work. As Mark says you need to protect the brick, using mark's Zircon /colloidal silica recipe

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

[LilyT]

I don't know about the physical requirements for natural gas at normal house pressures, but

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

[Marcia Selsor]

One way to help slow down freezing propane tanks is to have them plumbed to work two tanks in tandem for one burner. I have used this system for

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

[Stewart]

Thank you very much for your input. Would you suggest the burner port on and the chimney on the same side of the kiln?

 

Thanks,

Stewart

 

 

I don't know about the physical requirements for natural gas at normal house pressures, but

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

 

[Stewart]

Thank you very much!

 

Stewart

 

One way to help slow down freezing propane tanks is to have them plumbed to work two tanks in tandem for one burner. I have used this system for

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

 

[LilyT]

Hi, Stewart,

 

 

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

[Marcia Selsor]

I put my burners in the same side of the kiln as the chimney on larger kilns. Since I don't know how you are situating the cylinder, I can't say.

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