Benefit of adding kiln insulation?
Posted: Sat Sep 21, 2013 2:46 pm
Hi,
I have a Paragon Fusion 7 kiln (bought in January). It seems to loose a lot of heat at the interface between the lid and the top of the firebricks as well as through the lid. Just to give you an idea, the real heating rate is 450 dph when I set it to 600 dph. AFAP turns out to be approx 575 dph. Needless to say, my Hydro bill is something else as my total firing times are much longer than expected. And I guess that the elements will age more rapidly as they spend more time on than they should.
From a kilnforming perspective, I think that it does not really matter that I go too slow on the way up. But is this going to increase the likelihood of devitrification as I am not going through the critical zone fast enough? In fact, what is 'fast enough'? I could not find a range of acceptable rates for AFAP.
If I decide to insulate the lid to enhance the kiln efficiency, how about adding one layer consisting of several 3 inch firebricks on top of it? How about putting a strip of ceramic fiber on top of the brick wall (to close the gap)? Or you think that insulating these two areas would provide only marginal benefit?
Another idea that I am toying with is to figure out if whether this difference in heating rate is linear or not (by making a good old calibration curve at different rates) and adapt all my firing schedules accordingly. But that seems a lot of work...
Lucie
I have a Paragon Fusion 7 kiln (bought in January). It seems to loose a lot of heat at the interface between the lid and the top of the firebricks as well as through the lid. Just to give you an idea, the real heating rate is 450 dph when I set it to 600 dph. AFAP turns out to be approx 575 dph. Needless to say, my Hydro bill is something else as my total firing times are much longer than expected. And I guess that the elements will age more rapidly as they spend more time on than they should.
From a kilnforming perspective, I think that it does not really matter that I go too slow on the way up. But is this going to increase the likelihood of devitrification as I am not going through the critical zone fast enough? In fact, what is 'fast enough'? I could not find a range of acceptable rates for AFAP.
If I decide to insulate the lid to enhance the kiln efficiency, how about adding one layer consisting of several 3 inch firebricks on top of it? How about putting a strip of ceramic fiber on top of the brick wall (to close the gap)? Or you think that insulating these two areas would provide only marginal benefit?
Another idea that I am toying with is to figure out if whether this difference in heating rate is linear or not (by making a good old calibration curve at different rates) and adapt all my firing schedules accordingly. But that seems a lot of work...
Lucie
(I say the same thing about my 20 year old cat 
)