[Iforgot]

Hi World,

I need a diagram for a very small hard or soft brick gas kiln. I have one burner, I don't care if it's updraft or downdraft, It just needs to reach cone 8.


Thank You!

Darrel

[Iforgot]

P.S. I live in Colorado, so I need a high altitude plan.

[neilestrick]

What size shelves?

[Iforgot]

10 x 20"

[neilestrick]

I built a simple box kiln in grad school that I fired to cone 11 for small loads of salt glaze tests. The stacking area was about 3" larger all around than a kiln shelf. Along the long side of the shelf was a short bag wall 2.5" thick (brick on side), and the firebox was 4.5" wide. Instead of an arch, the top was spanned with old kiln shelves covered with 2 layers of soft brick. Fiber blanket or fiber board would work, too. Walls were 9" thick. The flue was just a brick left out of the top corner, opposite the burner port. It could be plugged or unplugged as needed. It wasn't pretty, but it only took a couple hours to build and fired great. No arch, no steel. Piece of cake! The simple layout of one shelf and a burner port could easily be beefed up with an arch, downdraft flue, etc. Just depends on how much work you want to do and how much money you want to spend. In fact, we did build two downdraft kilns with arches and doors with the same layout. They were built back to back with a shared chimney.

 Simple-Kiln.jpg (17.09K)
Number of downloads: 63

[Marcia Selsor]

Neil gives good advice. For high altitude you need to add about a third or more height to a normal chimney.
Somewhere out there there are specs for a specific height.

Marcia

[neilestrick]

We fired this in Utah, at an altitude at least as high as Denver. We used a power burner, so it did not need a chimney. If you're using a venturi burner, you'll need to figure out some sort of chimney for it. And if you build it right, you won't need to cut any bricks.

[Marcia Selsor]

True!
If you use forced air, the natural draft is irrelevant. Soe what type of burner do you have..venturi, or a forced air (with a blower)? I have built forced air burners following Don Bendel's design. It isn't difficult but they don't pass URL approval.
2" pipe, bell reducers, black pipe intersecting the 2" pipe with 5 small orafices drilled into the smaller pipe. A flange at the far end attached to a squirrel cage blower from Graingers. Air adjusted with a flat piece of metal over the blower's air intake. These were for propane.



Marcia

[neilestrick]

Yep, you can make a power burner for not much more than the cost of the blower. Of course, I strongly recommend some sort of safety system on the burner- at the very least a Baso valve with pilot. Unfortunately that will double the cost. But still much cheaper than buying a pre-built burner. Plus you'll save some money by not having to build a chimney......

[Iforgot]

neilestrick, on 07 February 2013 - 03:19 PM, said:

I built a simple box kiln in grad school that I fired to cone 11 for small loads of salt glaze tests. The stacking area was about 3" larger all around than a kiln shelf. Along the long side of the shelf was a short bag wall 2.5" thick (brick on side), and the firebox was 4.5" wide. Instead of an arch, the top was spanned with old kiln shelves covered with 2 layers of soft brick. Fiber blanket or fiber board would work, too. Walls were 9" thick. The flue was just a brick left out of the top corner, opposite the burner port. It could be plugged or unplugged as needed. It wasn't pretty, but it only took a couple hours to build and fired great. No arch, no steel. Piece of cake! The simple layout of one shelf and a burner port could easily be beefed up with an arch, downdraft flue, etc. Just depends on how much work you want to do and how much money you want to spend. In fact, we did build two downdraft kilns with arches and doors with the same layout. They were built back to back with a shared chimney.

Simple-Kiln.jpg

Thanks,

The burner I have is a weed burner, it's a 100,000 btu. will this work?

[neilestrick]

Depends on how big the kiln is and what kind of bricks you use. Go to the Ward Burner web site- there's a chart you can use to calculate how many btu's you'll need.

[justanassembler]

Iforgot, on 07 February 2013 - 09:11 PM, said:

neilestrick, on 07 February 2013 - 03:19 PM, said:

I built a simple box kiln in grad school that I fired to cone 11 for small loads of salt glaze tests. The stacking area was about 3" larger all around than a kiln shelf. Along the long side of the shelf was a short bag wall 2.5" thick (brick on side), and the firebox was 4.5" wide. Instead of an arch, the top was spanned with old kiln shelves covered with 2 layers of soft brick. Fiber blanket or fiber board would work, too. Walls were 9" thick. The flue was just a brick left out of the top corner, opposite the burner port. It could be plugged or unplugged as needed. It wasn't pretty, but it only took a couple hours to build and fired great. No arch, no steel. Piece of cake! The simple layout of one shelf and a burner port could easily be beefed up with an arch, downdraft flue, etc. Just depends on how much work you want to do and how much money you want to spend. In fact, we did build two downdraft kilns with arches and doors with the same layout. They were built back to back with a shared chimney.

Simple-Kiln.jpg

Thanks,

The burner I have is a weed burner, it's a 100,000 btu. will this work?

A lot of those 100,000 BTU weed burners arent rated for continuous duty and burn themselves up with a few (or less) firings. In terms of material costs, you're probably better off building something forced air and ditching the weed burner all together especially if you want to hit cone 8.

[neilestrick]

If you're planning on firing in reduction, I'm not sure the weed burner will give you the adjustability you need to control the atmosphere. Can you adjust the air intake?

If you build the kiln 22.5 inches square, which will allow you to use whole bricks (no cuts), your 10x20 shelves will fit just right with a 2.5 inch bag wall (brick on its side) and 4.5 inch (half brick) wide fire box. You'll need to find a couple of larger shelves for the top, or step in the top 3 rows of bricks to fit a smaller shelf. That give you a footprint of about 3.5 square feet of interior space. With soft brick, you can go up to 2 feet tall with the walls and have enough power to fire to cone 10. 7 cubic feet @ 14,000 btu/cf/hr = 98,000 btu. That's a fun size for a little gas kiln!

[Marcia Selsor]

Don't forget the stack (chimney) It is a little kiln but you will need a draft. What is your altitude?
I fired a Fast Freddie wood kiln in Latvia and another in Banff at 6000 ft.. The one in Banff was stalling at 1800 . Les Manning called fred Olsen and dais he forgot to mention high altitude in his directions. It makes a difference.
Your weed burner won't have any safety valve on it so watch it closely while you are firing.

Put a damper in the chimney so you can control the draft. Check out some kiln books to give you some ideas.

Marcia

[neilestrick]

In grad school (way back when) at Utah State we never had problems with chimney height because the fire code required that our stacks be several feet taller than the neighboring buildings!

[Marcia Selsor]

That is more than a fire code, that is a rule of thumb. The chimney should always be higher than the peak of the roof. During my first five years of college level teaching in Montana 1975-1980, the chimnies for the kilns exited on a second floor patio on the west side of an 8 story building. There was a downdraft from the predominantly West wind. The mechanics room was next to the kiln room and sucked the smokey air into the Liberal Arts building air vents . The ceiling air vents in the auditorium showed signs of soot.
After 5 years, the ceramics lab moved to a renovated building.



Marcia

[Iforgot]

Okay, i can't seem to find a power burner that is the right size for this kiln. is there any way that i could mabye put a blower next to a venturi burner so that I can develope an artificiasl draft so that I don't need to build a chimminey?



Darrel

[neilestrick]

Iforgot, on 10 February 2013 - 10:03 PM, said:

Okay, i can't seem to find a power burner that is the right size for this kiln. is there any way that i could mabye put a blower next to a venturi burner so that I can develope an artificiasl draft so that I don't need to build a chimminey?



Darrel

Doesn't really work that way. Go with a chimney or a power burner. Ward can build you a burner any size you want.

[Iforgot]

neilestrick, on 08 February 2013 - 01:36 PM, said:

If you're planning on firing in reduction, I'm not sure the weed burner will give you the adjustability you need to control the atmosphere. Can you adjust the air intake?

If you build the kiln 22.5 inches square, which will allow you to use whole bricks (no cuts), your 10x20 shelves will fit just right with a 2.5 inch bag wall (brick on its side) and 4.5 inch (half brick) wide fire box. You'll need to find a couple of larger shelves for the top, or step in the top 3 rows of bricks to fit a smaller shelf. That give you a footprint of about 3.5 square feet of interior space. With soft brick, you can go up to 2 feet tall with the walls and have enough power to fire to cone 10. 7 cubic feet @ 14,000 btu/cf/hr = 98,000 btu. That's a fun size for a little gas kiln!

so for the walls shoulsd i just put two bricks on there sides next to each to each other to equal 9"? also if i put a 4.5" layer of hard brick on the inside, next to a 4.5" layer of soft brick on the outside would i still have enough power to build it two feet tall and fire to cone 8?



Darrel

[neilestrick]

Yes, 9" walls. If you use hard brick and soft, you will need more btu's from your burners. Hard brick do not insulate as well as soft brick.