In the Studio: Small-Scale Extruding Daryl E Baird

Appears in the Mar/Apr 2018 issue of Pottery Making Illustrated.

Wish you had an extruder for a few projects here and there, but don’t need one for full-time use? If you’re going to use your extruder mostly for coils, handles, and other small, solid forms, you don’t need one with a large barrel or lots of extra dies. An extruder with a barrel that holds less than 10 pounds of clay and a few dies will do. For small extrusions—¼ to ½ inch in diameter—consider a hand-held extruder (1), which looks like a caulking gun. Hand-held extruders are inexpensive and are quick and simple to use—plus they’re easy to clean!

A typical model holds about 3–4 pounds of clay, while larger ones hold between 5–6 pounds of clay. Most models come with a basic die set for round, square, and ribbon extrusions, a set for making handles, a more specialized shape and coil set, and a tile trim set. Look for one with a removable barrel for cleaning.

Using a Hand-Held Extruder

Recently, a friend asked me to make an address sign for her new home. This project was the perfect test for a new hand-held extruder. Rather than use the basic dies that come with the set, I decided to make a DIY custom credit-card die so I could use my own designed shapes.

DIY Die

Using a clean, out-of-date credit card, draw the shape of the die opening you want, then trace over the lines with a Sharpie marker. If you make a mistake, remove unwanted lines with rubbing alcohol. Cut out the shape with a Dremel tool or an X-Acto knife (2). Use fine sandpaper to clean off any burrs around the edges (3).

Credit-card dies (4) aren’t suited for use in fully-filled, large-barreled extruders. Extruders with small barrels, three or four inches across, are ideal. Cut the die to fit into the round barrel. You can use one of the dies that came with the extruder as a guide for size (5). Make an extrusion to test the shape, then remove and refine the die as needed.

Home Address Sign

Roll out a large slab of clay just under ½-inch thick. Cut the slab into an oval shape using a serving platter as a template.

Use the small bull-nose die to extrude the edge trim for the oval (6). The height of the notch in the extrusion should match the thickness of the clay slab. Extrude a piece long enough cover the entire circumference of the slab. Attach to the slab immediately and apply even pressure all the way around to bond the trim to the slab without scoring the edge or applying slip (7). Add decoration such as leaves or flowers to the slab to personalize it for the home owner. Store the oval slab under plastic.

For numbers, use the T-shaped die, which has an opening about 1¼-inch wide and about 1 inch high (8). The extrusion is easy to shape while offering a large back surface area that will bond well to the oval slab. Extrude several lengths of the T-coils and occasionally spray them with water to keep them moist. Place them on a piece of drywall or cement backer board to help control drying and minimize the risk of warping.

Use a pencil to draw the outline of the numbers or letters you want directly on the drywall. Follow these pencil lines as you lay out the extrusions (9).

Mist the oval slab with water until the surface glistens. Lightly place the numbers on the surface. When properly positioned, apply light, even pressure repeatedly until the numbers are firmly in place. It isn’t necessary to distort the shape of the extrusion to achieve good attachment.

Keep the sign on the drywall wrapped securely in plastic for 2–3 days. Finally, place it on a dry piece of drywall and continue to allow it to dry slowly and evenly.

Excerpted form The Extruder Book: 2nd Edition by Daryl Baird and available from the Ceramic Arts Network Shop at https://ceramicartsnetwork.org/shop.