The Brent CXC wheel is mounted within an enclosure of heavy wooden counters built at the same height as the deck of the wheel. On the counter to the right of the wheel goes a ware board of wedged clay balls ready to throw. On the counter to the left of the wheel goes empty ware boards. Under the counters go up to 14" bats. Tools hang on pegs on the wall under the window. The flow of the work is from right to left, .......wedged clay to wheel..... formed piece to ware board. When the ware boards are full, they are placed onto the pegged rack to the left of the wheel. When the rack is full, all of the wares there are moved into the main ware storage area at the other side of the studio. There is a matching work area with another wheel just to the right of the work station pictured with the flow pattern going left to right. Both have windows that look out over the kiln yard to the Souhegan River.
Damper, with supporting track and seal
This picture shows a high alumina kiln shelf used as a damper slab (HiCore Setter Slab, Sola Basic Industries Div. of Engineered Ceramics). It sits in a "pocket" created utilizing 1 1/4" thick "splits" (thin brick) that supports the shelf all along the sides of the track that is formed. The damper then "seats" when it is closed into a small "pocket" at the rear of the track, to assure positive closure when the kiln is shut down. The support on each of the sides of the chimney is about 1/2", so for a 9" wide flue, the damper shelf is cut to 10" wide. Note the calibration on the damper in percentage open/closed, and the "hot" warning on the end that is handled.
Effects of Repeated Soda Firing on ITC 100HT Coating
These first pictures show the interior hot face surface of a newly built soda kiln after about 24 high temperature firings photographed on 10/4/01. The kiln is all new construction, was done as part of a workshop session, and is located in a college level institutional setting. Because of the workshop format of construction, there was some irregularity in the preciseness of the brick laying.
The sprayed ITC 100HT coating was applied onto brand new Thermal Ceramics 2500 insulating firebricks as precisely matching the directions from the ITC manufacturer as was possible. The kiln was then carefully dried, and then "dry fired" to cone 10 before any soda firing was performed in order to give the ITC 100 HT a chance to bond with the refractories without the influence of any soda atmosphere. The kiln has been fired as high as Orton cone 11.
Soda introduction for this kiln is supplied in a liquid form with a stainless steel air pressure powered sprayer inserted through multiple wall openings which are lined with cast refractory tubes that have also been coated with ITC 100HT.
The kiln has a hinged door with the brick to brick door seal first being ITC 100 HT coated, with a wash of alumina hydrate refreshed periodically as needed.
Wall Area Near Firebox Wall Area Near Soda Spray Port
10/4/01 Photo 10/4/01 Photo
The worst lining deterioration is, as one might expect, closest to the firebox areas. This area is subject to the greatest extreme of peak temperature, reducing atmosphere, and thermal shock, along with the impact of the soda attack. The left side of the leftmost photo above shows the closet area of the IFB wall near the high alumina hard refractory lined firebox area. It is in the worst shape of any part of the kiln, and yet still only mildly affected. The photo to the right shows one of the uppermost soda spray ports, with the "dribbling" effect of un-vaporized liquid soda solution quite apparent below the port.
As of the two dozen firings, it is my general impression that the ITC 100 HT has acted to retard but not eliminate the deterioration of the insulating firebrick surface. The Thermal Ceramics brand of brick is one of the most resistant to the effects of soda firing, however they too will eventually erode, slag, and spall terribly. Soda and salt firing is incredibly destructive to insulating firebrick in general, and if longevity of the lining is an overriding concern, IFB is a poor choice for this function. Rapid hot face lining deterioration and failure is a "cost of doing business" for the decreased energy consumption and rapid cooling possibilities provided by an IFB lining over one composed of hard refractories.
Important Note: There is no scientific "control group" of unprotected Thermal Ceramics firebrick being utilized here, so any conclusions about ITC 100HT performance in protecting the IFB is purely anecdotal and experiential.
I plan on updating these photos over time to track the deterioration of the wall surfaces in an online "photo album" Stop back.
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This page last updated:
07/25/2003 02:43 PM