Kiln Building Refractory Bricks and Insulating Firebrick for Furnace Building and Repair.
There are two main types of high temperature fire brick: Soft brick (IFB) Insulating Fire Brick and Hard or Dense Fire Brick.
Both types are made of refractory fire clay, alumina to make it more refractory (resistant to heat), and grog which is ground up, pre-fired clay. Grog helps limit the expansion and contraction that fire bricks go though in heating a cooling cycles.
Dense fire bricks are very heavy at about 8 pounds each. Dense firebrick resists abrasion and chemical atmospheres so these are used in wood burning kilns and furnaces, salt and soda kilns, as well as in power plant fire boxes.
Insulating Fire Brick (IFB or Soft Bricks) are porous and light weight at about 4 pounds apiece. They usually pale yellow and that is generally lighter in color than dense bricks which are are a more orange tan color. IFB are used in electric and gas kilns and furnaces where abrasion and chemical attack are not a factor. If you can stick your finger nail in a brick then you have Insulating Firebrick.
Both insulating and dense fire bricks are available in a large number of standard tapered and straight shapes.
The basic sizes of start with dimensions of 9x4.5x2.5" or 9x4.5x3". There are many tapered versions (Arch bricks and Wedge bricks) of either size for creating arches and circles with eithr 9" thickness or 4.5" thickness.
There are also Split Bricks which are half thickness : 9x4.5x1.25"
With our decades of experience, let the experts at Sheffield Pottery guide you to the correct bricks for your project!
Refractory shapes include precast cement and fused or sintered refractory products that are formed prior to installation in furnaces, boilers or other high temperature equipment. Refractories are hard, heat resistant materials and products such as alumina, silicon carbide, fire clay, bricks, precast shapes, cement or monolithics and ceramic kiln furniture. Ceramics and refractories have high melting points are suitable for applications requiring wear resistance, high temperature strength, electrical or thermal insulation or other specialized characteristics.
Kiln building refractory fire bricks, blocks, and tiles are stacked to form insulating furnaces, boilers or other thermal process vessel walls. The refractory fire bricks are usually cemented together with refractory mortar.
Shown top is a new gas kiln made with soft refractory fire bricks from Sheffield Pottery by John Zetner of New Hampshire Potters Guild.
CHOOSE SOFT BRICKS FOR INDOOR OR WELL COVERED AREAS : Used in Gas and electric Kilns
2 1/2” and 3" Series: STRAIGHTS , WEDGES AND ARCHES
G20 = 2000 degrees F
G23 = 2300 degrees F
G26 = 2600 degrees F
G28 = 2800 degrees F
Note: Soft bricks can be cut with a regular carpenter's hand saw to create custom shapes.
CHOOSE HARD BRICKS FOR OUTDOOR APPLICATIONS : Used for wood burning kilns. Soda kilns generally require 70% alumina hard fire bricks.
HIGH HEAT DUTY -Economical high-duty refractory fire bricks will go to cone 31-32. Suitable for backup linings, and other areas that encounter moderate operating temperatures. Not suggested for abrasive conditions. (equivalent to Empire) 2 1/2” except where * (3”)
SUPER DUTY -Exhibits high strengths and low shrinkage, good resistance to thermal shocks. Can be used as the inside lining of kiln. Recommended for blast furnace stoves, open hearth and coke oven checkers, glass tanks and anywhere a high density, low porosity super duty brick is desired. Will go to cone 33-34. (equivalent to Clipper) 2 1/2” except where * (3”)
70% ALUMINA -A chemical and ceramic bonded 70% alumina brick designed for the following applications: Electric furnace roofs, ladle bottoms, side walls and slag lines, rotary kilns, cement kilns, torpedo ladles, tundishes, and hot zones of lime kilns.
Note: there are no drawings of the 3 inch series bricks so here are the dimensions: