Kilns can
be built out of many things and castable refractory is one of the materials we
rarely consider. Perhaps it should be considered more since the castable is reasonably
priced, easy to mix, and easy to use.
As John
Britt explains in today’s post, if you are comfortable with casting plaster and
making molds, you can handle building a solid arch kiln with castable
refractory. – Jennifer Harnetty, editor.
Casting an Arch
Determine
the size of your arch and cut enough expanded polystyrene arch pieces to form
the entire arch. Set it on four-inch “legs,” which can be dropped out after
casting. Make the exterior wooden mold form by cutting two identical arch
pieces out of 3⁄4-inch plywood that are longer than the foam arch by the
thickness of the kiln wall. Establish the length of the kiln and cut three 2×4s
to that length, attaching two to the bottom sides of the plywood arch forms and
one at the top (the top 2×4 is visible in image #1). Fill this form with the
polystyrene arches.
Mix the castable, paying
specific attention to the manufacturer’s instructions. You can use a commerical
castable,
Pryor-Giggey Phlocast 30 Low cement, and added Rib-Tec 400 1-inch stainless
steel pins. Use approximately four pounds of steel pins per 100 pounds of castablerefractory. When mixing, wear a respirator and use thick gloves—the castable is caustic
and the pins are sharp.
Pour the castable in
4-inch-high sections made from 3⁄4-inch plywood strips so the castable refractory
don’t bow, being sure to pack down and smooth out each section. Form a V-shaped
groove at the top of each section and let the castable refractory harden. Separate each section with plastic wrap before repeating—the plastic
creates an expansion joint. After the castable castablehas cured for 24
hours, take the outer plywood off and drop the legs out from underneath,
allowing the interior expanded polystyrene forms to drop out.
Above ways
just for your reference.
No comments:
Post a Comment