Jeff Lawrence on sat 21 jun 97
Hi,
Both Vince Pitelka and John Baymore have cautioned recently against too
great heat loss through kiln floors.
I'm on the brink of building an MFT clone -- using one-piece fiber modules
for walls and roof, while planning to build on a brick base for both walls
and car. Vince was warning about the cinder blocks falling apart and John
was describing cement slab failure. I dislike the idea of a nice new slab
crumbling before its time. Almost as bad as the base falling out from under
the kiln.
Has anybody got any insulative improvements in the base of the MFT design
they'd like to share?
TIA.
Jeff
Jeff Lawrence
Sun Dagger Design
ph/fax 505-753-5913
John H. Rodgers on mon 23 jun 97
-- [ From: John H. Rodgers * EMC.Ver #2.5.02 ] --
It sounds as if you are building a typical MFT car-type Kiln but using fiber
instead of bricks. A few years ago I was involved in constructing a similar
kiln for my shop in Alaska. There were special needs, and Nils Lou, a member
of this Clayart group, was asked and did provide the design as well as the
burner system. There were several unique features incorporated in the design
to meet our needs.
Ours was an MFT built as an envelope kiln. A metal shell was constructed on
a frame with steel wheels set on tracks.This allowed the envelope to be
rolled over the fixed kiln floor. Stainless steel buttons were welded inside
and 6" thick fiber blocks were installed on walls and ceiling.The floor
itself was built on two steel I-beams laid parallel to one another with
angle iron stiffeners welded crossways. The angle irons served as supports
for the floor. The angle irons were welded close enough together that
firebrick could be laid in and they would be supported. There were three
layers that made up the floor, One of hard brick, one of soft brick, and
then 1"x12" x 24" shelving laid end-to-end and side by side. At one end was
an upright steel wall, also covered with fiber blocks. The chimney was also
located at that end, as were the burner port, and exhaust port.
When the kiln table as we called it, was loaded, the kiln envelope was
rolled on its tracks over the table to butt to the wall at the end. This
closed the kiln and it was then secured and fired.
This method is an alternative you or someone else might want to try. Other
than these changes it's a typical MFT.
John Rodgers
-------- REPLY, Original message follows --------
Date: Saturday, 21-Jun-97 11:08 PM
From: Jeff Lawrence \ Internet: (jml@sundagger.com)
To: CLAYART LIST \ Internet: (clayart@lsv.uky.edu)
Subject: MFT kiln floor insulation
----------------------------Original message----------------------------
Hi,
Both Vince Pitelka and John Baymore have cautioned recently against too
great heat loss through kiln floors.
I'm on the brink of building an MFT clone -- using one-piece fiber modules
for walls and roof, while planning to build on a brick base for both walls
and car. Vince was warning about the cinder blocks falling apart and John
was describing cement slab failure. I dislike the idea of a nice new slab
crumbling before its time. Almost as bad as the base falling out from under
the kiln.
Has anybody got any insulative improvements in the base of the MFT design
they'd like to share?
TIA.
Jeff
Jeff Lawrence
Sun Dagger Design
ph/fax 505-753-5913
-------- REPLY, End of original message --------
Sheila Clennell on mon 23 jun 97
>----------------------------Original message----------------------------
>Hi,
>
>Both Vince Pitelka and John Baymore have cautioned recently against too
>great heat loss through kiln floors.
>
>I'm on the brink of building an MFT clone -- using one-piece fiber modules
>for walls and roof, while planning to build on a brick base for both walls
>and car. Vince was warning about the cinder blocks falling apart and John
>was describing cement slab failure. I dislike the idea of a nice new slab
>crumbling before its time. Almost as bad as the base falling out from under
>the kiln.
>
>Has anybody got any insulative improvements in the base of the MFT design
>they'd like to share?
>
>TIA.
>
>Jeff
>Jeff Lawrence
>Sun Dagger Design
>ph/fax 505-753-5913
Jeff: The MFT is probably the most duplicated kiln in North America.
There must be hundreds, if not thousands in use. If you want real good
advice ask Nils Lou, he designed it. I'll bet he's never heard on a
potters MFT falling over because the cement blocks crumbled. A cement pads
work well too, if they are cured properly. The ones I have built kilns on
were soaked with water everyday for a couple of weeks. If you build a kiln
on fresh cement the heat will cause capillary action to draw the moisture
up thru the cement and it's rocket launching time. Cement needs to be cured
just like whiskey. I think John and Vince are wise in advising caution but
if properly insulated both pads and blocks have stood the test of time for
me. If you're worried put another row of IFB's down. And spray your kiln
and floor with ITC 100. You should especially spray the fiber to protect
your kiln and your health.
Good luck with the MFT. I earned my living for a long time out of that kiln.
Cheers,
Tony
Sheila and Tony Clennell
Gleason Brook Pottery
Box l0, RR#2,
Wiarton, Ontario
NOH 2TO
Canada
Phone # 1 (519) 534-2935
Fax # 1 (519) 534-0602
E-mail clennell@bmts.com
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