Sian Gethin Posted August 5, 2019 Report Share Posted August 5, 2019 I have a Kiln which working well. Is over fired in the bottom and never reaches temperature in the top . No matter of firing schedules , soaking . All the elements are in working order, Its to have too many elements in the base to compare with the top . Has anyone ever experience this ? Link to comment Share on other sites More sharing options...
Babs Posted August 5, 2019 Report Share Posted August 5, 2019 What kind of kiln? How are you packing it? What is the cone difference on each area of kiln? Gas wood electric?. Top or side loading. Makes it easier to work out. Link to comment Share on other sites More sharing options...
Bill Kielb Posted August 5, 2019 Report Share Posted August 5, 2019 As above and: Picture of the kiln, picture of the element layout, downdraft vent? The more you can tell and show the more likely there will be good ideas. Link to comment Share on other sites More sharing options...
Hulk Posted August 5, 2019 Report Share Posted August 5, 2019 Hi Sian! I have a Skutt KM1027-3 (it is over thirty years old - all manual - newish elements), which I've fired eight times, four bisque, four glaze; it does not heat evenly (I set cone packs on every level)! Definitely cool on the top, especially when going short up there (for smaller pieces). Any road, last glaze firing I staggered the upper shelves/levels - I have half shelves only - much better results! All levels within half a cone! My thinking was that the cooler top area will get more radiant heat; a side benefit being it's possible to fit more pieces without crowding - particularly bowls. Other variables to consider - how tightly packed, how heavy/thick are the pieces, and how much variation in size (hence shading neighbors or being shaded...). Below is a crude depiction; I've bought more shelf stands/posts so I'll have more flexibility in future. Link to comment Share on other sites More sharing options...
Bill Kielb Posted August 5, 2019 Report Share Posted August 5, 2019 @Hulk Wise shelf displacement. At top temperatures there is virtually no convection (this is why when you pull a site plug no air comes out, it’s too thin at high temperatures to contain a significant amount of heat) so all the pieces that can SEE the elements will get more heat than those that cannot. This is called radiation and is the main way your kiln heats at upper temperature. Better to stagger shelves as they will receive radiation from any element they can see between the shelves. Sort of like being in the sun or shade with zero wind. Link to comment Share on other sites More sharing options...
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