Nan Rothwell on mon 13 oct 97
I wrote a long, over-wordy request last week looking for advice on rebuilding
my salt kiln. Then I thought about how unwilling I am to read long,
over-wordy ClayArt entries. So I'm trying again, breaking my questions down
into more digestible bites...
First question: Does anyone have specific encouragement or warnings about
building a salt kiln with the combination of soft bricks (Thermal Ceramics
K-23's) on the interior with ITC100 coating? I've followed the ongoing
general thread in ClayArt. But if anyone has details of how salt kilns have
survived over time built with those materials, please let me know! (My
previous kilns have been hardbrick.)
Second question: I've always stacked pots loosely to allow for proper
circulation of salt and wood ash. And my most recent kiln had a LOT of extra
space between the walls and shelves. What do you consider a good distance to
leave around stacks of shelves in a salt kiln?
Third question: Both of my salt kilns have been propane-fired downdrafts,
with burners coming in from the sides (the walls that support the arch),
hitting bagwalls, and with flames exiting from a central exit flue to a back
chimney. In both kilns, I created an extra-large channel in front of the
burners, so that I could throw in the salt plus some wood. And in both
kilns, that's been the area that deteriorated most badly. So my question
is, how about creating an exterior firebox? (My logic is that if that's the
area that goes first, how about isolating it from the main body of the kiln,
so that I could replace just it, and not the whole thing, when it goes...) I
know that propane has a relatively short flame. Would I be losing the most
important heat by making the propane travel through a short firebox first?
Does anyone have specific advice/ideas about a design for such an exterior
Fourth and final question: I plan to re-use my old Ransome venturi burners.
If I don't build an external firebox, should I change the flame pattern of
my kiln so that the burners come in at the back? (I've read that is more
efficient than from the side...)
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