Safety Concerns for Firing a Downdraft Electric-to-Gas Kiln Conversion

[Callum Donovan-Grujicich]

Hello, I am doing some research into converting an old electric kiln into a downdraft gas kiln. However, I have not found much information on safety concerns which are specific to this type of kiln, other than the general concerns in an electric kiln such as toxic fumes. Could anybody give some safety tips or important information so I can ensure my converted kiln is safe to use?

Thank you,

Callum

[liambesaw]

Safe in what way?  

It will contain heat if that's what you're worried about.  As far as fumes go, you're looking at a lot of carbon monoxide and volatilized metal just like any other kiln.

You'll want to be firing out doors or in an extremely well ventilated area.

My biggest issues firing with propane were that the tanks freeze at peak usage, and that can be mitigated by sitting  the tank in a water bath.  

The firings can be uneven in a converted kiln, but that's the nature of the beast.  I wouldn't be too worried about anything else. Of course use caution whenever using a gas torch for something.

[Bill Kielb]

1 hour ago, Callum Donovan-Grujicich said:

Hello, I am doing some research into converting an old electric kiln into a downdraft gas kiln. However, I have not found much information on safety concerns which are specific to this type of kiln, other than the general concerns in an electric kiln such as toxic fumes. Could anybody give some safety tips or important information so I can ensure my converted kiln is safe to use?

Thank you,

Callum

Most conversions require the user to be safe in all aspects. If you buy a gas kiln, some of the safety requirements include:

• pilot safety
• high limit temperature safety
• gas safety including redundant gas valves and regulator
• high and low pressure gas cutoff

The owner / operator is generally responsible for

• Proper draft / flue
• Proper piping and leak checking with emergency shut off valves as appropriate and safe kiln hookup practices or code requirements
• Limiting toxic fumes and exposure in the area of the kiln and local ventilation required to make safe in the area of use.
• Safe  operation of the kiln Including eye safety, protective ware  non hazardous operation, proper loading, unloading, burn protection, signage as necessary, clearances to combustibles .......
• The safety of all firings especially  for anyone firing the kiln or helping to fire.

Folks who make their own downdraft generally don’t expect them to get Gas or UL certified so they generally  take on the responsibility (Personally) for the first Set of bullet  points through diligent supervision as well as the second set of bullet points as an experienced potter. 
 

Might sound ominous but to an experienced potter they probably are over cautious and realize the responsibility.

 

 

 

[Callie Beller Diesel]

I don’t know what the rules are in Ontario, but you can’t buy suitable gas burners in Alberta without a gas fitters licence anymore. The only way you’ll find any is on the second hand market, and they don’t come up much. 

You can build a raku kiln with a tiger torch, but I’m not certain it’d get hot enough for bisque or glaze temps. 

Edited to add: the gas and electrical codes are different here, and you really do need to look up a lot of stuff. Most provinces classify kilns as custom industrial builds, so they’re in the same category as things like hospital boilers, or tar sands equipment. Because of some industrial accidents a few years ago, most provinces are enforcing their codes more stringently regarding appliance certification than they did a decade ago. Hence not being able to buy a burner unless you are certified install one, and a gas fitter isn’t allowed to hook it up unless the kiln is CSA certified, which is $$$ to an engineering firm that offers such services.