Why You May Want to Upgrade Your Kiln With 3 Inch Brick
At Skutt, we use two different brick thicknesses to construct our kilns, 2.5″ and 3″. Some of our models come standard with 3″ brick (All 1227 and 1627 models) because we need the added insulation for optimum performance given the chamber size, the power available, and the element design. Other models (not all) have 3″ brick available as an optional upgrade.
On some models, like the KM1027 208V 1PH, upgrading to 3″ brick will raise the Cone rating from Cone 6 to Cone 10. On other models, like the KM1027 240V 1PH, the power supply available (240V) already makes it a strong Cone 10 kiln. What you are gaining with the upgrade is energy efficiency and sometimes element life. With the added insulation the kiln does not have to work as hard to achieve peak temperatures so the elements are happier and the power meter spins a little less.
It is hard to say exactly how much you would save on your energy bill since it depends on your particular firing habits but on average of 15% is a reasonable estimate.
There are a few downsides. The first is, you lose one inch of shelf space on the interior of your kiln since the brick is thicker.
The second, which some people do not view as a negative, is that the kiln takes longer to cool. Artists working with high fire glazes like this because often times they slow cool their glazes anyhow. Unfortunately, the kiln still cools very fast during this range so in order to achieve the rich micro-crystal affect they like in their glazes, they will still have to program a slow cooling ramp. The only advantage is that the kiln may not need to cycle on as much to slow the cooling. Where the kiln cooling is really slowed down in its cooling is between 1000F and room temperature. Again due to individual firing habits it is hard to give an accurate estimate of how much longer it will take but if you are in production it could be the difference between being able to turn a kiln load in a day and not being able to.
How To Upgrade
Upgrading an existing kiln is obviously not practical so if you want 3 inch brick you need to order it when you order your kiln. If a model has the option of being upgraded to 3 inch brick you will want to choose the model name with the “-3” at the end of the name (Example “KM1027-3”). use the chart to determine if upgrading is an option for your desired model.