Building a catenary arch waste oil fueled kiln

[Dave Earley]

I am planning to rebuild a kiln I made decades ago.  It will be a catenary arch 4x4x4 ft fired with propane and waste oil.  I have most of the material just need to pour a concrete base.  I am looking for anyone who might want to learn/share in this. I am located in Strongsville Ohio.

Kiln foundation is poured, waiting to cure.

Edited May 13, 2022 by Dave Earley
Update

[neilestrick]

Fun project! What type of construction materials do you plan to use- hard brick, soft brick, castable? And what type of waste oil?

[Dave Earley]

Hi, I have most of the bricks, fiber insulation, kiln furniture, etc. from the kiln's previous incarnation.  The arch and floor and partial chimney are hard brick with some soft brick and fiber for insulation.  I will buy more fiber and maybe some vermiculite for added insulation.  I see a piece of corrugated culvert pipe in the woods behind my house could be chimney material. I have a friend with an auto repair business who can supply drain oil. I also need a system to transport the oil.  I am using ideas from Dennis Park's " A Potters Guide to Raw Glazing and Oil Firing." Also Fred Olsen's "The Kiln Book." The original kiln was built in 1978 and then built again in 1982.

David Earley

 

Edited March 9, 2022 by Raku slip question

[Dave Earley]

Foundation is poured, now waiting for it to cure.

[Jose]

On 3/9/2022 at 11:05 AM, Dave Earley said:

Hi, I have most of the bricks, fiber insulation, kiln furniture, etc. from the kiln's previous incarnation.  The arch and floor and partial chimney are hard brick with some soft brick and fiber for insulation.  I will buy more fiber and maybe some vermiculite for added insulation.  I see a piece of corrugated culvert pipe in the woods behind my house could be chimney material. I have a friend with an auto repair business who can supply drain oil. I also need a system to transport the oil.  I am using ideas from Dennis Park's " A Potters Guide to Raw Glazing and Oil Firing." Also Fred Olsen's "The Kiln Book." The original kiln was built in 1978 and then built again in 1982.

David Earley

 

Happy building and thanks for the book recs. I'm planning out my small cat arch kiln build as well. Not owning the land makes it hard to build mid/large kiln. Best wishes w/ the work;  would definitely love to help you but I'm in the Southwest! 

[Dave Earley]

I am also using g "Building Pottery Equipment" by roger Harvey and Sylvia and John Kolb,  Watson-Guptill 1975   Today I started build the arch form. after completing the build  I threw a lot of pots, loaded the kiln and have since been struggling with fuel and burner issues.  first time I preheated with propane weed burners, then switched to fabricated waste oil nozzles.  Kiln stalled at 1150 F.  Now I'm building a propane power burner system after acquiring a larger propane tank. Not giving up!

Edited October 5, 2022 by Dave Earley
adding photo/Users/davidearley/Downloads/catenary arch.jpg.afphoto

[Dave Earley]

The waste oil suction nozzles I used were not up to providing enough heat.  On to phase 2.  I am purchasing used oil furnace burners as I had success 45 years ago using them.  I just need to modify the nozzles to push more oil into the kiln.

Here is one modified burner, dual nozzle, maximum flow 3.5 gal/hr.  that should do it according to Olsen's The Kiln Book, p172.

Edited April 6, 2023 by Dave Earley

[Mark C.]

I have buildt at leaqst 3 of these out of hardbick like yours in the 70s. They consume massive amouts of BTU so waste oil is the right fuel choice. I stronly suggest adding anotherf homemade layer ver the arch to insulate . I made (from memory ) lots of vermiculite  and you can add sawdust in a homemade mortar (wich will flake oiff if you take the kiln down . Use a mix of 3 parts silica 1 part to 2 parts fireclay and some epk as a binder-again lots of vermiculite. Some  folks add small amount of portland cement but it will crack in fact no matter what it will crack so the trick is mix this as dry as you can still wetting the ingredients  slightly-the dryer the less skrinkage. This extra insulation will fill the cracks and keep the heat in. keep the kiln covered from rain of course. Google homemade kiln coatings and see what others have done

This will aid in kiln reaching temps. A forced air oil drip system will work fine for fuel

Here is my old cat arch in the middle 70s during reduction-As you can see not very efficientt

Edited February 24, 2023 by Mark C.

[neilestrick]

I agree with Mark. One layer of hard brick is too inefficient, even with the layer of fiber over it. There are relatively inexpensive ways to add insulation to the arch, like a mixes of sand, fireclay, cement, and sawdust. The cost of the materials will probably be less than the savings in fuel.

[Dave Earley]

I'm thinking of a vermiculite/clay coating covered with metal sheets from the wall of my above ground pool which blew out. It is good to recycle.

 

[Kelly in AK]

Cool project!

I believe the chimney also needs to be two layers of brick thick, at least to the top of the kiln. 

[Bill Kielb]

On 3/3/2023 at 10:10 AM, Dave Earley said:

I'm thinking of a vermiculite/clay coating covered with metal sheets from the wall of my above ground pool which blew out. It is good to recycle.

Aside from reasonable rigidity (mechanical rigidity, very important), uncompressed fiber is a really really easy way to improve performance. Inches of thickness in fiber is everything in reducing thermal losses.

[Mark C.]

I agree on the fiber but 1st the mortar need to fill the holes (chinking the voids) then fiber then it need to be kept dry always (metal roof) Fiber should not get wet as well as the mortar .I always keep a few boxes of fiber on hand myself. Just in case

[Russ]

On 3/3/2023 at 9:10 AM, Dave Earley said:

I'm thinking of a vermiculite/clay coating covered with metal sheets from the wall of my above ground pool which blew out. It is good to recycle.

 

Like Mark said I highly recommend at least 2in of kaowool if not more. It will cut your firing time substantially and will prevent your kiln from cooling too fast which will affect your glazes. IMHO  A single layer of brick is not an issue if its properly insulated.  My  80cubic foot c10 wood fired kiln is a single layered hard brick insulated with kaowool  that is going on its 24th year. The only problem ive had was the door was cast with fireclay vermiculite mix cracked and crumbled. I replaced it 15yrs ago with a factory made castible and its held up like a champ.

[Dave Earley]

This summer I got two used furnace oil burners and added a second nozzle to each one.  After preheating to near 900 Fahrenheit with propane weed burners, I turned on the oil burners. I was using waste motor oil with a little diesel added to thin the mix.  At around 1700 F I noticed oil leaking under the kiln and shut it down.  the oil was too heavy to be atomized and was spraying in a stream.  I am now researching rocket burners for economical wood firing.

Edited December 5, 2023 by Dave Earley

[Bill Kielb]

11 hours ago, Dave Earley said:

This summer I got two used furnace oil burners and added a second nozzle to each one.

Might help, my experience as an old guy  - oil burners are pretty old technology so lots of reading if you just  Google oil burners. Some  decent plain English reading here IMO  https://inspectapedia.com/heat/Oil-Burner-Nozzle-Selection-Guide.php#FiringRate. Picking a correct pressure important, used to be no less than 100 psi which has grown to 140 psi for finer droplet size, better aeration. 140000 btu per gallon is how I learned it (no2) and nozzle dispersion critical to cover the firebox without impingement. Anyway, pressure, size, cone angle all contribute significantly and mostly really good filtration to avoid clogged nozzles.

[Russ]

Wood firing doesnt have to be done with a fancy rocket yada yada yada.... grates with plenty of room under them for coals AND a blower setup to force air across the wood works really well and is quite simple.  Easy to fire a large kiln from candling temp to c10 flat in 5hours.

[Dave Earley]

here is a drawing of proposed wood fire box added to the kiln pictured above