Straights - The standard straight is 9×4½×2½ inches or 9×4½×3 inches and available in larger sizes up to 18 inches long, 9 inches wide, and 4½ inches thick.
Square edge tile - This term refers to “big” straights, which comprise 12×12 inches up to 24×12 inches with thickness ranging from 1½ to 3 inches.
Soaps - A term used to describe a half brick in width such as 9×2¼×2½ inches or 9×2¼×3 inches.
Splits - A term used to describe the thickness of a brick thinner than 2½ inches, i.e., splits come in 1, 1¼, 1½, and 2-inch thicknesses.
Arch - This shape tapers in thickness along the width over its entire length and is used to make sprung or circular barrel arched roofs either 4½ inches or 6 inches in thickness.
Wedge - This shape tapers in thickness along the entire length of the brick and is used to make sprung or circular barrel arches 9, 12 or 13 inches in thickness.
Skew - A shape having a certain taper on one side or end to enable a sprung arch to be built. Four major types are available in both side and end skews that relate to the rise of the arch.
Here are some recommendations that will greatly assist you on your firebrick purchase.
• The vast majority of pottery kilns are constructed of high duty or super duty brick.
• Use extreme care when considering used refractories for building kilns. In most cases, you won’t know the conditions under which they were exposed. If they’ve been removed from a furnace, it’s usually because the lining failed. Properties of refractories deteriorate with exposure to extreme heat, chemical vapors, mechanical stress and thermal cycling.
• While insulating firebricks can be easily cut with any kind of saw, hard bricks require special equipment, like a tile cutting saw, to cut. Design your kiln to take full advantage of available shapes, and when possible to minimize the amount of hard bricks you must cut.
Jim Wunch is the owner of Larkin Refractory Solutions located in Lithonia, Georgia. He has more than thirty years of professional experience with refractory manufacturers and installers worldwide.