Loading on bottom

I would like to get some opinions regarding loading pieces directly on
the bottom of the kiln for glaze firing.

Don't do it! Use a kiln shelf. The shelves are easier to replace or repair
if you have some sort of problem with your glaze running. Steve in Tampa,
Florida, USA


"L.Mac" wrote in message
om...
I would like to get some opinions regarding loading pieces directly on
the bottom of the kiln for glaze firing.

Also the floor of a kiln is MUCH cooler than the kiln temp, and you will
seriously underfire the glazed pieces on the floor. This also applies to
bisque firing, although you mightn't notice it until the piece cracks later
due to stresses in the base.

Dave


"L.Mac" wrote in message
om...
I would like to get some opinions regarding loading pieces directly on
the bottom of the kiln for glaze firing.

"Mud Dawg" wrote in message
. com...
Don't do it! Use a kiln shelf. The shelves are easier to replace or
repair
if you have some sort of problem with your glaze running. Steve in Tampa,
Florida, USA


"L.Mac" wrote in message
om...
I would like to get some opinions regarding loading pieces directly on
the bottom of the kiln for glaze firing.


Absolutely! Having tried that once, and destroyed the bottom of a kiln (one
with bottom elements to boot), i would say a shelf is much cheaper than a
repair.

Wayne in Key West
(Oh, to be young and stupid again......NOT!)

Thanks everybody for their words of wisdom.
LMac

On Mon, 21 Jul 2003 17:30:02 -0400, "psci_kw"
wrote:


"Mud Dawg" wrote in message
.com...
Don't do it! Use a kiln shelf. The shelves are easier to replace or
repair
if you have some sort of problem with your glaze running. Steve in Tampa,
Florida, USA


"L.Mac" wrote in message
om...
I would like to get some opinions regarding loading pieces directly on
the bottom of the kiln for glaze firing.


Absolutely! Having tried that once, and destroyed the bottom of a kiln (one
with bottom elements to boot), i would say a shelf is much cheaper than a
repair.

Wayne in Key West
(Oh, to be young and stupid again......NOT!)

The floor shelf in a kiln needs to be only 1/2" to 1" off the floor to
allow heat to circulate under it. The small loss in space would be far
better than having to refire all the pieces on the floor because the bottoms
were underfired, or having to replace floor bricks because some glaze ran
off and lifted a great chunk of brick out. Glaze actually dissolves (fluxes)
refractory insulating brick so a small amount will leave a large crater. Its
not worth it.

Dave

--
David & Elaine Coggins

www.users.bigpond.com/dcoggins
"Brad Panek" wrote in message
om...
As a question to your answers on using a kiln shelf at the bottom of
the kiln.

How high off the bottom is this lowest shelf?

Save yourself some heartache. Place your bottom shelf on 1/2" stilts and
leave it.

Steve in Tampa, FL
"Brad Panek" wrote in message
om...
As a question to your answers on using a kiln shelf at the bottom of
the kiln.

How high off the bottom is this lowest shelf?

I have found that you can't put a shelf directly on the bottom of the
kiln because it will prevent it from heating correctly. So then I
would think that you must put the bottom shelf on stilts to allow for
correct heating, so 4 inches or what?

My answer is that unless you have elements in the floor of the kiln I
would go ahead and place pieces on the floor of the kiln (rather than
losing a lot of space by putting in a shelf on stilts). I would also
suggest that these bottom pieces be wiped completely free of glaze on
their bottoms and your normal height up the sides, and also that you
don't put runny or thick glazes on the bottom. Occasionally glaze on
a piece will run and stick to the bottom and this can usually be
pulled out with little bit of soft kiln brick stuck to it. You can
also kiln wash the floor, however this does not seem to prevent the
glaze from pulling up pieces of the brick.

I guess it depends on how careful you are with your glazing, and how
often you have glaze drips that go down past the foot of the pot. If
you have had accidents and placed low fire pots in your high fire, and
made a puddle, by all means use a shelf...


Lindsay MacArthur wrote in message
. ..
Thanks everybody for their words of wisdom.
LMac

On Mon, 21 Jul 2003 17:30:02 -0400, "psci_kw"
wrote:


"Mud Dawg" wrote in message
.com...
Don't do it! Use a kiln shelf. The shelves are easier to replace or
repair
if you have some sort of problem with your glaze running. Steve in
Tampa,
Florida, USA


"L.Mac" wrote in message
om...
I would like to get some opinions regarding loading pieces directly
on
the bottom of the kiln for glaze firing.


Absolutely! Having tried that once, and destroyed the bottom of a kiln
(one
with bottom elements to boot), i would say a shelf is much cheaper than
a
repair.

Wayne in Key West
(Oh, to be young and stupid again......NOT!)

If you only need 1/2" stilt on the bottom I will try it out. Thanks


"Mud Dawg" wrote in message om...
Save yourself some heartache. Place your bottom shelf on 1/2" stilts and
leave it.

Steve in Tampa, FL
"Brad Panek" wrote in message
om...
As a question to your answers on using a kiln shelf at the bottom of
the kiln.

How high off the bottom is this lowest shelf?

I have found that you can't put a shelf directly on the bottom of the
kiln because it will prevent it from heating correctly. So then I
would think that you must put the bottom shelf on stilts to allow for
correct heating, so 4 inches or what?

My answer is that unless you have elements in the floor of the kiln I
would go ahead and place pieces on the floor of the kiln (rather than
losing a lot of space by putting in a shelf on stilts). I would also
suggest that these bottom pieces be wiped completely free of glaze on
their bottoms and your normal height up the sides, and also that you
don't put runny or thick glazes on the bottom. Occasionally glaze on
a piece will run and stick to the bottom and this can usually be
pulled out with little bit of soft kiln brick stuck to it. You can
also kiln wash the floor, however this does not seem to prevent the
glaze from pulling up pieces of the brick.

I guess it depends on how careful you are with your glazing, and how
often you have glaze drips that go down past the foot of the pot. If
you have had accidents and placed low fire pots in your high fire, and
made a puddle, by all means use a shelf...


Lindsay MacArthur wrote in message
. ..
Thanks everybody for their words of wisdom.
LMac

On Mon, 21 Jul 2003 17:30:02 -0400, "psci_kw"
wrote:


"Mud Dawg" wrote in message
.com...
Don't do it! Use a kiln shelf. The shelves are easier to replace or
repair
if you have some sort of problem with your glaze running. Steve in
Tampa,
Florida, USA


"L.Mac" wrote in message
om...
I would like to get some opinions regarding loading pieces directly
on
the bottom of the kiln for glaze firing.


Absolutely! Having tried that once, and destroyed the bottom of a kiln
(one
with bottom elements to boot), i would say a shelf is much cheaper than
a
repair.

Wayne in Key West
(Oh, to be young and stupid again......NOT!)

you don't need much height. resting a shelf on the kiln floor is a classic
"conduction" situation for heat transfer - the fastest method of heat transfer
drawing heat away from the lower shelf. having the shelf up a small amount
changes the situation to no longer conduction but radiation - the slowest form
of heat transfer, heat loss.

think of your floor as a giant ice cube (on the scale of heat going on). is
THAT where you want to fire your pots?

meanwhile when i do unglazed pieces i usually rest them on the floor and
between burners to save shelf space for other stuff.

see ya

steve




Subject: Loading on bottom
From: (Brad Panek)
Date: 7/29/2003 9:32 AM Pacific Daylight Time
Message-id:

If you only need 1/2" stilt on the bottom I will try it out. Thanks


"Mud Dawg" wrote in message
. com...
Save yourself some heartache. Place your bottom shelf on 1/2" stilts and
leave it.

Steve in Tampa, FL
"Brad Panek" wrote in message
om...
As a question to your answers on using a kiln shelf at the bottom of
the kiln.

How high off the bottom is this lowest shelf?

I have found that you can't put a shelf directly on the bottom of the
kiln because it will prevent it from heating correctly. So then I
would think that you must put the bottom shelf on stilts to allow for
correct heating, so 4 inches or what?

My answer is that unless you have elements in the floor of the kiln I
would go ahead and place pieces on the floor of the kiln (rather than
losing a lot of space by putting in a shelf on stilts). I would also
suggest that these bottom pieces be wiped completely free of glaze on
their bottoms and your normal height up the sides, and also that you
don't put runny or thick glazes on the bottom. Occasionally glaze on
a piece will run and stick to the bottom and this can usually be
pulled out with little bit of soft kiln brick stuck to it. You can
also kiln wash the floor, however this does not seem to prevent the
glaze from pulling up pieces of the brick.

I guess it depends on how careful you are with your glazing, and how
often you have glaze drips that go down past the foot of the pot. If
you have had accidents and placed low fire pots in your high fire, and
made a puddle, by all means use a shelf...


Lindsay MacArthur wrote in message
. ..
Thanks everybody for their words of wisdom.
LMac

On Mon, 21 Jul 2003 17:30:02 -0400, "psci_kw"
wrote:


"Mud Dawg" wrote in message
.com...
Don't do it! Use a kiln shelf. The shelves are easier to replace
or
repair
if you have some sort of problem with your glaze running. Steve in
Tampa,
Florida, USA


"L.Mac" wrote in message
om...
I would like to get some opinions regarding loading pieces
directly
on
the bottom of the kiln for glaze firing.


Absolutely! Having tried that once, and destroyed the bottom of a
kiln
(one
with bottom elements to boot), i would say a shelf is much cheaper
than
a
repair.

Wayne in Key West
(Oh, to be young and stupid again......NOT!)











steve graber