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raku kiln mailbox style

updated mon 21 jan 02

 

Craig Clark on fri 18 jan 02


I don't think that you need any type of a stack. Just build the kiln as
an updraft, as all of the raku kilns that I've ever seen are built.
As far as the placement of the burner(s), if you're making the kiln that
small you'll only need one burner. You can either cut a burner port into the
front, side or back of the kiln. THe burner orientation will be
horizontal...or you can place the burner under the kiln. THe burner will be
oriented vertically (flame coming out the top works best). Cut the burner
port in the center of the kiln on the bottom.
In all cases use pieces of old fire brick to split the flame and give
yourself several inches between the bottom of the kiln and the underside of
the shelf that you place your tiles on.
One other thought. Consider how you plan on removing the tiles before
you place them. Practice grabing them a few times with your tongs before you
fire. I've found that leaning tile like pieces against an old soft or hard
firebrick works quite well.
I don't know how attached you are to the idea of useing the old mailbox
as your kiln but consider that the ideal shape for a kiln, or so I have been
told and read (I attribute this info to several different teachers, and
authors- check out Daniel Rhodes on kilns, same, same with Olsen "The Kiln
Book."), is a cube.
The more you depart from the basic cube the more difficult it is to get
an even firing in the kiln, especiallY in the case of an updraft with
natural aspiration. I say this eventhough this really isn't that great a
concern in the case of a small kiln.
Many raku kilns are not shaped like cubes (mine isn't, the big one is a
cylinder.) Besides that, a post box kiln sounds like it will be really
cool! Maybe we can get something going on the thread for the oddest,
smallest, most unique kiln that acutually works.Perhaps the most lavish
and/or the most economical. We could have several catagories. Anyone
interested? How about it Mayor?

Craig Dunn Clark
619 East 11 1/2 st
Houston, Texas 77008
(713)861-2083
mudman@hal-pc.org

----- Original Message -----
From: "Virginia Dains"
To:
Sent: Friday, January 18, 2002 3:14 PM
Subject: Raku Kiln mailbox style


> Hi All,
>
> Im looking into our metal scrap pile for building a small raku kiln to
> be used mostly for slab and tile work. Id like to put it up on a stand
> similar to a mailbox-on-a-post with access through a door opening to the
> front. Slabs could be slid out like a pizza. Anybody have any
> suggestions how to set a venturi burner and provide air
> circulation..Would it need a stove pipe stack?
>
> Thanks From Virginia
> Auburn, CA
>
>
____________________________________________________________________________
__
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.
>

Virginia Dains on fri 18 jan 02


Hi All,

Im looking into our metal scrap pile for building a small raku kiln to
be used mostly for slab and tile work. Id like to put it up on a stand
similar to a mailbox-on-a-post with access through a door opening to the
front. Slabs could be slid out like a pizza. Anybody have any
suggestions how to set a venturi burner and provide air
circulation..Would it need a stove pipe stack?

Thanks From Virginia
Auburn, CA

Richard Jeffery on sat 19 jan 02


Hi

a lot of what I raku fire are clock faces - my first kiln was built with
that in mind. I made mine from soft brick, built into the [ugly] brick
barbecue at the end of the garden. it was off the ground, but not so high
that I couldn't rest the burner on a building block.

my starting point was Steve Branfman's splendid book. Door at front was
originally shaped brick - as these decayed I replaced it with a fibre door
wired onto an old fridge shelf. The brick lid [bolted together] went the
same way. No need for a stack in this case - besides, you need to have
access to the flue for some level of control - and a brick over the opening
is a lot easier to contrive than a damper on a flue.

I like the front loader approach for these things - I have a stainless steel
kitchen tool like a miniature paddle from a pizza oven to slide things in an
out.

However, I built a fibre top hat kiln last year. Since then I haven't used
the brick kiln at all - it's probably full of hibernating wee beasties right
now. The fibre comes up to temperature so quickly (20 mins - brick was
anything up to 90 minutes, especially when damp - it's outside all the time,
albeit under a wooden cover) that it's just so much more economical.

so - I'm left wondering what to do with the brick kiln - I had planned a
rebuild - but now not sure I would make another in the same way. If you can
make a fibre front loader, I would go down that road.

To my mind, the issues around having the thing off the ground are to do with
stability and safety, not efficiency. I guess it depends on what space you
have. I would be reluctant to balance a kiln on a support - I think I would
want a very solid structure with secure attachments.

you could always build a barbecue and put the kiln on top....




Richard Jeffery

Web Design and Photography www.theeleventhweb.co.uk
Bournemouth UK



-----Original Message-----
From: Ceramic Arts Discussion List [mailto:CLAYART@LSV.CERAMICS.ORG]On
Behalf Of Virginia Dains
Sent: 18 January 2002 21:14
To: CLAYART@LSV.CERAMICS.ORG
Subject: Raku Kiln mailbox style


Hi All,

Im looking into our metal scrap pile for building a small raku kiln to
be used mostly for slab and tile work. Id like to put it up on a stand
similar to a mailbox-on-a-post with access through a door opening to the
front. Slabs could be slid out like a pizza. Anybody have any
suggestions how to set a venturi burner and provide air
circulation..Would it need a stove pipe stack?

Thanks From Virginia
Auburn, CA

____________________________________________________________________________
__
Send postings to clayart@lsv.ceramics.org

You may look at the archives for the list or change your subscription
settings from http://www.ceramics.org/clayart/

Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.

Virginia Dains on sun 20 jan 02


Thanks for your thoughts.

I searched the archives and got lots of good ideas. The safety issue is
worth considering...balancing a hot box on a pole... but it is just a
matter of foot-pounds = weight and distance above the counter weight so
that doesnt concern me, its going to be a permantn installation. i have
several sizes and shapes of old water pressure tanks which I have been
eyeing as a possible body after lining with wool.

Now further..... a few weeks back someone posted about a tile setter
that they strung with wires so that the whole rack could be moved into
the reduction vessel. Anybody want to elaborate?

Secondly.. how would a plate rack (for china paint) hold up under
consecutive use in raku? My current slab tiles are 8" X 10" and unglazed
for 1/2" around the edges. I have been leaning them around the side of
"garbage can" kiln but they tend to shunt heat and I dont get even
temps.

Virginia