why my home build gas kiln does not fire to cone 6?

[rtl]

It's an old kiln. 26" x 27" depth x 37 hight

 

Flat top with one brick rise to flue: 5" x 9"

 

It use to have an opening of 11 x 15" and I closed it w/firebrick to 5 x 9"

 

4 Venturi burners.

 

After 7 hours it reached 1250 F. degrees, and was climbing then very slowly

that I ended up shutting it down.

First time flue was almost closed

2nd time I left the flue wide open.

What should I do? I would like to fire to cone 6

Thanks for your help,

Ruty

[Guest JBaymore]

Could be many reasons. If you can give a LOT more information that would help us diagnose the possibilities.

 

A number of photos showing the outside and inside of the unit would be a GREAT help.

 

best,

 

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

[Lockley]

Could be many reasons. If you can give a LOT more information that would help us diagnose the possibilities.

 

A number of photos showing the outside and inside of the unit would be a GREAT help.

 

best,

 

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

 

 

 

I totally agree with John's post. I recommend that you use the google search function on this page. Search for Ward Burner Systems. Ward Burner Systems provides a lot of information about the design of Kiln type requirements. There are a number articles which may help you.

I am a novice, raw recruit, to Pottery. However I have been a metal smith for years during which I have built many furnaces in heat ranges up to cone 10. I also recommend The Kiln Book by Frederick L. Olsen.

 

The bottom line on any kiln or furnace is the Heat in BTU vers the Volumn. Building a kiln, forge, or melting furnace from scratch is tricky and needs to follow a good set of plans to be satisfactory. The tuition at the school of self taught is about right, but the labs are pure heck.

 

Good Luck, Lockley

[Guest HerbNorris]

Have you fired this kiln to cone six before?