Published Jun 18, 2014
As Dana Bilello-Barrow was developing her voice and her skills with clay, she realized that she would often be disappointed by her post after glazing. What resonated with was the tactile connection she had with the raw clay so she decided to try to find ways to maintain that through the firing. Her solution was barrel firing.
In today's post, an excerpt from Naked Raku and Related Bare Clay Techniques, she shares a cool way to develop organic patterning on barrel fired posts.- Jennifer Poellot Harnetty, editor
Get the Bare Facts!
When it comes to surfaces, nothing is as natural as decorating a bare clay surface with fire. Charlie and Linda Riggs join other pioneers in the naked clay movement with their innovative alternative firing techniques. Discover how to get a variety of effects with raku and pit firing in
Naked Raku and Related Bare Clay Techniques.
Check it out and download an excerpt here.
It is possible to create a truly unique finish on your pottery by utilizing readily available materials in your studio. This chapter demonstrates how a tape resist method is used to create random patterns on a properly prepared pot. The pot is placed in a semi-controlled atmosphere that encourages smoke to travel around the pot and leave a color pattern that resembles wood inlay.
Creating the Pot
When starting, it is important to choose the proper clay. Not any clay will work, but since you will not be exposing the clay to any harsh temperature changes or thermal shock it is not necessary to use a clay that has a lot of grog. Instead, a clay with little or no grit is preferred to achieve a pot with a high shine. Laguna B-Mix without grog is a good choice because it is a smooth clay that has some of the same finish qualities as porcelain, but is an easier clay to work with during the throwing stage. Since the color effects come from the smoke that rises from the bottom of the combustible chamber, it is important to keep in mind the shape of your piece. Therefore, it is best to avoid harsh shoulders, which can prevent the smoke from reaching the rim. Soft curved shapes work best with this technique.click to enlarge!
Preparing the Pot
If you prefer, you can use terra sigillata on a bone dry piece of pottery to achieve a nice shine. To apply terra sigillata, center the pot on a banding wheel and choose a soft brush such as a hake brush or a makeup blush brush. Coat the pot with two to three even coats of terra sigillata.
As soon as the sheen disappears on the pot, buff with a soft cloth. Touching the pot with bare hands can leave fingerprints in the terra sigillata; therefore, it is recommended that you wear gloves when handling the pot from this time forward. Gallery gloves work well.
When the pot is finished, let it dry completely before firing. Bisque fire the pot to cone 08. At this temperature the pot will maintain the shine from either the burnishing or terra sigillata techniques.
Create the Design
Now that the pot has been fired to cone 08, it is time to create your tape resist design. While the design options are endless, keep in mind the positive and negative spaces on the pot. The portion of the pot that is covered in tape will be lighter in color than the spaces that you leave exposed to smoke. Any brand of masking tape will work. As demonstrated in the photos, tape is torn into strips of various lengths, widths and shapes and leaving the edges of the tape raw. Affix the strips onto the pot in a random pattern. Move the pattern around the pot. If you affix the strips lightly or leave creases in the tape it, will allow the smoke to seep under the tape, adding to your design and patterns. If you have used terra sigillata in the preparations stage, be careful not to remove the tape from the pot at this point as the tape can pull the terra sigillata off the piece and leave the area dull.
Smoking the Pot
Ensure that a good bed of coals has been established at the bottom of the smoking chamber. These coals need not be glowing red; rather they should be dark pieces of smoking charcoal created by the remnants of the kindling noted in the above section. Place the lid loosely on the trash can for approximately five minutes to cool the smoking chamber.
Remove lid and place the pot on kiln stilts in the center of the smoking chamber. Kiln stilts facilitate flow of smoke around the ceramic piece and reduce the possibility of inconsistent patterns on the pot. Sprinkle a bed of sawdust in the smoking chamber. Sawdust should also be placed in the ceramic pot to ensure consistent smoking within the pot. Fill the smoking chamber with newspaper and two handfuls of sawdust then light.
When the paper begins to burn and smoke rises, place the lid loosely on smoking chamber and allow the smoke to travel around the pot turning the pot brown. Allow the piece to smoke for a period of 8–12 minutes. Remove lid and repeat the process until the non-taped areas are dark brown. Heat infusion should begin to curl the tape.
Do not allow the tape to significantly burn. This will cause you to lose the design patterns created by the tape. If burning tape is encountered, then immediately place the lid on trash can to eliminate fire or remove the piece from the container.