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cast chimney

updated mon 9 apr 01

 

David Hendley on tue 19 may 98

Here's my idea.
I wonder if anyone has done something similar.
How'd it work?
Does it sound feasable?

Put a 12" cardboard concrete form (Sonotube) inside a
18" Sonotube.
Center it, anchor the two together with wire.
Fill up the space between the two with homemade castable
refractory mix.
Instant kiln chimney.

I'm thinking of 2 or 3 foot long sections, so they don't get too
heavy or hard to cast.
Castable mix would be something like equal parts
fireclay, bauxite grog, ground up- insulating fire bricks
(golf ball size and smaller), and cement.
The wall thickness would end up being about 2 3/4" thick.
The inside form could be burned out during the first firing.

I already have all the materials on hand.
Left over Sonotubes from display pedestals, fireclay and
bauxite (unlimited supply) from the shut down firebrick plant....
Comments and suggestions appreciated.

David Hendley
Maydelle, Texas
hendley@sosweb.net
http://www.farmpots.com

DIANA PANCIOLI, ASSOC. PROF. on wed 20 may 98

Yep, I made a chimney like this. It worked.

But I used Baskin Robins ice cream containers for the core. Only problem,
until the metal rings burned away, I got a chrome fuming backing up in to
the kiln! Was a long time ago. I might be smarter now.

Diana
EMU

On Tue, 19 May 1998, David Hendley wrote:

> ----------------------------Original message----------------------------
> Here's my idea.
> I wonder if anyone has done something similar.
> How'd it work?
> Does it sound feasable?
>
> Put a 12" cardboard concrete form (Sonotube) inside a
> 18" Sonotube.
> Center it, anchor the two together with wire.
> Fill up the space between the two with homemade castable
> refractory mix.
> Instant kiln chimney.
>
> I'm thinking of 2 or 3 foot long sections, so they don't get too
> heavy or hard to cast.
> Castable mix would be something like equal parts
> fireclay, bauxite grog, ground up- insulating fire bricks
> (golf ball size and smaller), and cement.
> The wall thickness would end up being about 2 3/4" thick.
> The inside form could be burned out during the first firing.
>
> I already have all the materials on hand.
> Left over Sonotubes from display pedestals, fireclay and
> bauxite (unlimited supply) from the shut down firebrick plant....
> Comments and suggestions appreciated.
>
> David Hendley
> Maydelle, Texas
> hendley@sosweb.net
> http://www.farmpots.com
>

Dannon Rhudy on wed 20 may 98


----------------------------Original
message----------------------------
Here's my idea.

Does it sound feasable?
.....Put a 12" cardboard concrete form (Sonotube) inside a
18" Sonotube.......

It does sound feasible, David. Would the walls be thick enough,
do you think? How much would each section weigh, do you estimate?
And, how would you fasten them/stack them/attach them going up?
Notched? Flanged so that one would slide into/over the next?
Exterior support of some kind? I'm thinking about wind, stability,
etc.

We used some castable material for part of a chimney for a wood
kiln at UNT, but did not do it as you suggest - put it on as a
sort of thick plaster around a metal sleeve.

I take it your kiln is being rebuilt even as I write.

Dannon Rhudy
potter@koyote.com

Cameron Harman on thu 21 may 98

I have used the Sonotube method for industrial kilns quite
successfully. The catch is, I do not keep the chimney so hot as to
need the cast refractories for very long.
The usual practice is to put an air bleed at the base of the
chimney to drop the temperature from kiln temperature to about
1400 degrees, then put i space after the cast chimney (often about
3/4" ) open to the atmosphere to cool the rest of the flue to
about 900 degrees. At this point I use a sheet metal (fabricated)
tube that is wider than the original chimney to accommodate the
larger amount of gasses ( kiln gas plus air at the base of the
castable plus the final cooling air. )
If you have a 9" diameter flue hole, then the cast chimney can be
12" diameter and about as high as the kiln (if it is a down
draft), then a 15" diameter sheet metal stack up to about 20 feet
above ground level. Oh yes, I put a small damper in the first air
leading to the base of the cast chimney for control purposes.

I have built a lot of kilns this way and they all work very well.
I do not suggest that you follow my outline exactly as every case
is different. Email me if you have some questions.

--
********************************************************
Cameron G. Harman, Jr. President Ceramic Services, Inc.
215-245-4040 fax 215-638-1812 visit us http://www.@kilnman.com
1060 Park Ave. Bensalem, PA 19020
THE place to go for answers to all YOUR kiln and dryer questions
********************************************************

BDUDEE on thu 21 may 98

A thought on your cast chimney. Instead of cardboard inside of cardboard,
try
cardboard inside of steel coragated culvert material. The culvert will provide
the
structural support the chimney will need. Other solid cylindrical forms could
be
concidered, concrete pipe etc..


Bill Downs in Mt. View Hi
(one of the wettest places on earth)

Pancioli on sun 8 apr 01


I made a cast chimney once using Basking Robbins ice cream containers
taped together for the inner form, metal pipe for the outside form. It
worked.

Diana