Published Aug 22, 2011
I haven't ever attempted to make anything on an architectural scale in my studio. It seemed a bit too intimidating to me. But a couple of months ago, Stephani Stephenson came to town to film a DVD on making architectural ceramics in a small, home studio setting.
Stephani's DVD made me realize that architectural ceramics is quite doable in small spaces if you go about it in a smart way. In today's post, as a little preview to the DVD, I am presenting an article on designing and making a fireplace surround. - Jennifer Poellot Harnetty, editor.
There are a couple of methods for designing a fireplace surround, and you’ll need complete measurements and specs for all parts of the fireplace (figure 1). For the surround I’m demonstrating here, all components were combined in the forming process so the tiles curve from one surface to the next, unlike typical tiled surrounds where the mantel face tile and firebox return are made separately then assembled on installation and the tiles meet at the edges.
Design and Template
>I first plotted a general design and layout on the computer, adapting it to my measurements and enlarging everything by 9% to compensate for clay shrinkage (figure 2). I then sketched the design to scale on rosin paper, fine tuning the arch curve and angles of the cuts along the arch (figure 3). Once the design was finalized, I then traced half of the design onto heavy plastic sheeting (figure 4). This served as my template for both left and right sides of the surround.
Transferring the Design
For this surround, roll out a 1-inch thick slab of clay and transfer the pattern from plastic to clay with a water-based marker (figure 5). On my plastic template I had drawn a dotted line, 2¼ inches from the inner line of the arch. This line indicated how big the slabs would need to be to include enough clay for the firebox return along the arch. To make the 4×8 and 4×4 rectangular blocks for the lower surround, I rolled out oversized slabs that allowed for the firebox return and extra selvedge on all sides.
Forming the Return
To construct the straight blocks below the arch, I place a 2×4 next to a plaster block measuring 12×18×3 inches. The 2×4 can be clamped or nailed down, but in this case the weight of the plaster block kept it in place. Since the base of my draw tool was made from a piece of 2×2, the edge of the 2×4 was set the width of a 2×2 away from the edge of the table and the plaster block was set against the 2×4.
I then place each slab with the “return” edge down onto the 2×4 and against the plaster (figure 6). A length of 2×2 helps me hold the edge of the slab in place. Holding the 2×2, I slowly ease the rest of the slab down onto the plaster, then use a broad flat paddle to flatten it (figure 7).
A piece of good quality wooden lath is drawn over the surface in a ‘screeding’ motion to further compress and flatten the clay (figure 8).
Shaping the Return
To prepare the clay for shaping with a draw tool (see box), moisten and compress the curve (figure 9). Lightly position the 2×2 base of the draw tool against the 2×4, placing one hand on both the base and the table edge and the other hand on the metal template. Pull the draw tool down the length of the table, continuing to press it against the 2×4 as you pull it along.
When you pull a draw tool to shape clay, you can go in either direction. The first pull should be steady but light since the metal template scrapes and removes clay as it’s drawn along, and catches if too much clay piles up. Re-wet the clay, make a second then a third pull, each time increasing pressure, deepening and defining the form. After the clay stiffens slightly on the plaster block, remove the 2×4, then compress and round the edge of the return.
Wobbles, gouges and false moves are generally made at the beginning and the end of each pull. Leaving extra clay at both ends of the slab allows for these errors on ‘landing’ and ‘takeoff’, yet give a smooth ‘flight’ in between! The ends are later cut away and discarded or recycled. To form the return on the arch or curved sections, transfer lines from the template onto a 2-inch thick piece of sheet foam and cut away the foam along the inner curve. Lay the arch slab onto the foam, letting the curved edge of the slab extend out 2¼ inches to form the return. Placing rosin paper between the foam and clay allows for easy repositioning over the foam. To form the return along the arch, I first place plastic food wrap over the slab, then use my palm, the fleshy part of my hand between thumb and forefinger and a soft rubber rib to ease the clay down over the foam, lightly compressing the clay, taking care not to stretch or distort it. To shape the return, I remove the metal template from the wooden base and pull it along the curve, using the same pulling technique. Allow the clay to stiffen in place then trim and smooth the return edge.
Cutting Tile Blocks
To cut the slabs into tile blocks, use the transfer lines as guides, but double check them with a square. Place plastic food wrap over the slab and impress lines with a metal straightedge. Cut the tile by pressing straight down with a broad stiff putty or spackling knife (figure 11). This will create 90° cuts with well-finished edges. Curved portions of the return can be cut in a similar fashion.
Leave the pieces in place until leather hard (figure 12). The keystone is made at the same time, but isn’t trimmed until all the other pieces are completed and laid out to dry to ensure that its size, side angles and return complemented the rest of the arch. Then, because I use a relatively smooth clay body, I hollow out the backs of the pieces at this stage (figure 13).
Bullnose tiles were needed for one base of the firebox, so that the firebox could be swept. Lower left and right corners of the surround needed to incorporate the transition from return trim to bullnose (figure 14). Additional shaping, smoothing and texturing with rasps was done at the leather-hard stage. Pieces were then dried and fired on edge, bisqued to cone 04, stained, then fired to cone 4. Hearth tiles were extruded, stained and fired in a similar manner. The surround is currently awaiting installation (figure 15).
Stephani Stephenson is a full time tilemaker, sculptor and architectural ceramist, currently residing in Encinitas, California. She is a member of the Potters Council and a popular presenter and workshop instructor. See her work at http://www.revivaltileworks.com.
Tip #1: For a symmetrical design, draw or trace half of the design onto clear plastic with a permanent marker. Fold the plastic and trace the ‘half design’ onto the other half of the plastic. Unfold. On the reverse side of the plastic, retrace your lines with a water based marker. Place the plastic, right side up, onto moist clay. Rib or smooth the plastic onto the clay. Pull the plastic away to reveal your transferred design.
Tip #2: When I pull a draw tool, I visualize my upper body as a fixed extension of the draw tool, using my legs to move me rather than flexing my arms to pull, inhaling before I start, exhaling slowly as I pulled (think tai chi—slow even steady pull).