If you have ever done raku firing, you are probably aware that the raku firing process should not be used for pots that are intended to serve food. The rapid firing, removal of the ware at the red-heat stage, and subsequent post-firing all contribute to surfaces that remain porous after firing. So it is best for decorative pots or sculpture. If you are looking for another application for raku, today’s post just might be for you.
In today’s post, an excerpt from our latest free download Successful Tips and Techniques for Raku Firing: How to Select Raku Clays, Glazes, Kilns and Combustibles – 2nd Edition, Barbara VanSickle shows you how making a raku mural gives you a chance to explore making art for the walls. – Jennifer Harnetty, editor.
The idea of creating raku murals happened quite naturally. A few years ago I was fortunate enough to be asked to create a retirement gift for a dear friend and former colleague. I needed to design something very special. I knew that he was partial to raku surfaces. During visits to his home, I was struck by its impressive open-concept architecture with the tall, wide wall spaces. The more I thought about what to make, the clearer it became: a raku mural.
The problem was I had no idea on how to proceed. My experience with raku was limited and, although I had previously created some murals for a school installation with children, I’d never attempted anything like this. The school project gave me some of the technical knowledge and experience of creating, drying and mounting the clay tiles but I needed inspiration for the subject matter.
I turned to my own environment and my love of Art Nouveau stained glass to come up with the design for “India Blue Peacock.” Two doors down the road from me lives a family that raises India Blues. I hear the peacock calls all through the days from early spring to late fall. Linking the peacock with the Art Nouveau stained-glass look was quite natural.
Since making this first mural, I have continued to look to my own experiences and environment for inspiration.
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Prepare Paper Template
Begin a mural by making a series of small drawings. Whatever your inspiration, remember that simplified edges work best (as in stained glass) and that some areas naturally lend themselves to being cut into sections. If you have areas that would be too large for one tile, plan how you’ll adapt your work by adding divisions in the tiles that add to the overall design. Enlarge the drawing to actual size, then use a marker to highlight the lines. On larger projects, you’ll need to cut your plan into smaller pieces. If so, number each piece on the back to make it easier to reassemble later (figure 1).
Prepare the Slab
Roll out a slab to a thickness of approximately 3/8 inch on a textured material, such as rubber shelf liner or placemats. The textured rubber material provides a perfect backing for the tile, which helps prevent warping during drying and firing. It also makes the slabs easy to carry without distorting (figure 2). Remove any unwanted marks with a rib and rolling pin, being sure to roll the slab no thinner than 1/3 inch. Thinner tiles are more likely to warp during drying and firing (figure 3). Peel off the rubber backing, then join slabs together as needed (figure 4). Place the slabs on a flat surface, and cover it with plastic for about a day.
Transfer the Design
Lay the paper pattern on the slab, then using a blunt tool, such as the dull end of a wooden skewer, trace over the marker lines. When the template is removed, you will be able to use the incised lines as guides for adding any relief or textures. Trim the edges of your panel using a straightedge and a sharp, dry knife, then cut the panel into individual tiles (figure 5).
Create the Pieces
Arrange your cut tiles on a large board or table to form your mural and add any relief or impressed designs. Once you’ve completed all the additions, cut through any pieces that overlap from tile to tile. Clean up and smooth all edges.
Cover the entire mural with plastic, and place sandbags strategically to keep the pieces as flat as possible during the drying phase. Tip: I make sandbags by cutting up old sheets into 12-inch squares, then scoop sand onto them, bring the edges up and fasten them with rubber bands. They are a great tool to have around the studio (figure 6). Check on the mural daily as warping can be reduced by relocating the sandbags if you catch it right away. Once leather hard, turn the tiles over and recover with plastic to allow them to dry slowly (about a week in my studio). Remove the plastic, turn the tiles right side up, and give the work at least another day to dry before bisque firing.
Reassemble all the pieces to form the mural before glazing. This makes it much easier to apply the glazes accurately. If you’re masking any areas, apply your tape or resist material. I prefer to use black graphic tape as it provides excellent contrast, and can easily be rearranged without leaving residue on the bisqued tiles. It also creates perfectly straight lines (figure 7). Apply glazes according to your original drawings. I prefer to brush them on by completing all of one glaze color at a time on the entire mural before moving to the next glaze (figure 8).
I fire my mural pieces in a raku kiln (figure 9). Due to the extreme range of reduction effects that influence the glaze surface and color development, try to fire tiles that will be side by side in the mural in the same load. If possible place them in the same reduction chamber together. Use a pyrometer and time each fire to get the greatest consistency between loads, and try to fire under the same conditions if your work will take longer than a day. This process takes considerable planning but the results are well worth the effort. If you get too much or too little reduction on a particular piece, remember that you can always refire.
Assemble the mural
Reassemble the mural (figure 10) and measure the finished height and width. This is the base measurement for your mounting board. Where and how your work is hung determines the type of material for mounting. If you’re working on a project any larger that 8 square feet, use plywood. For smaller murals, I recommend 5/8-inch-thick medium density fiber board (MDF) as it is lighter, though on larger murals it can warp.
For a mural the size made here, mark the MDF board roughly three-fourths of the way up from the bottom edge and drill ¼-inch holes 2 inches in from either side. Countersink the holes on the front of the board deep enough for a ¼-inch nut to be flush with the face. Drill two large diameter washers to accept the hanging wire and bend them slightly outward. Attach the washers to the back of the board through the ¼-inch bolt head and tighten (figure 11).
Prime the MDF and, when thoroughly dry, apply paint (I prefer matt black). Allow the paint to dry completely for 24 hours, then spread a good quality construction glue to the mounting board, keeping it off anywhere that will show when done (figure 12). Beginning at the bottom, apply the glue to the back of the tiles, one or two at a time, and assemble. The glue dries very fast, so you’ll need to work quickly (figure 13).
When it is completely dry (at least 8 hours), grout the mural. Remember in your planning that grout comes in many colors so it can further enhance the final project. Follow the manufacturer’s instructions. Once the grout begins to thicken, pour it on the mural paying particular attention to the small spaces between each tile (figure 14). Gradually remove the extra grout using a damp sponge, changing the water frequently (figure 15). Allow to dry.
Thread heavy duty picture wire through the holes in the washers and adjust the length appropriately.
Be sure to download your free copy of Successful Tips and Techniques for Raku Firing for more articles on how to raku, and select raku pottery clays, glazes, kilns, and combustibles.