Tuesday, February 11, 2014

Saggar/Pitfire prep

Howdy,
 Feb. 23 and 24th I will be participating in the On and Off Fredericksburg Road Studio Tour. I will be demonstrating how I do my saggar firings and my pitfirings. I've invited Northside ISD art teachers, and my potter friends to participate in the these demonstrations. I would like to explain for teachers and potters new to the process the needed materials for the demonstration. I will have much of these materials, but it is always good to have extra. Pitfire demonstration will begin at 12 pm on Saturday. The work will be pulled around 4 or 5. The saggar firing will be demonstrated on Sunday at 12 pm. This will be an ongoing process. Once the kiln is hot, individual pots will be pulled about every 30 to 45 minutes.

The image above is of my dolls. The heads are terracotta and not fired alternatively. The bodies were in either the pit or raku kiln.

I do a foil wrap with both my Saggar firing and Pitfire firings. A saggar is done in the raku kiln using propane as the heat source. The pitfire, is a brick kiln and uses sawdust and wood pieces as the heat source. Both types of firing “tattoos” the bare clay, creating deep colors ranging from pinks to orange to deep purple. Blacks can appear with the pitfire.

Clay choices: The type of clay I use often is Dillo or Porcelain. High fire clays allow the clay to absorb the colors better. Our Buff with grog will work but the colors are not as deep. I don’t use terracotta type clays because I don’t get interesting colors on the surface. The clay needs to be bisque at 08 and don’t bisque higher than 06. Greenware is not strong enough to endure the shock of the temperature change. The pieces can be rough with texture or smoothed with burnishing.

Burnishing is easy: When the pot is bone dry (greenware), wipe baby oil onto the surface. With a sponge damp a small section with water and rub with a polished stone (no flaws) or with a light bulb. It will create a shiny surface. Fire clay at 08 to keep the shiny surface. Burnishing doesn’t work well with groggy clay. Terra sig might work for groggy clay (but I’ve only just started experimenting with it.) Polish with wood wax when finished with the alternative firing process.


Materials
Ferric Chloride: Etchant Solution found at Radio Shack
Fungicide: 1-Pint Liquid Copper Fungicide, found at Home depot
Sawdust: Dog betting found at Lowes and sometimes at Home depot
Copper Scrubby: sometimes found at dollar tree
Heavy duty foil. The bigger the better
Plastic gloves: protect hands from stains
Optional:
Cotton soaked in salt (dried out)
String soaked in salt (dried out)
Dog biscuits, leaves
Coffee grounds
Plastic buckets for the chemicals. Brushes without any metal parts.
Extra propane tanks. The grill tanks are easy to replace and refill. Home depot, HEB, Lowes
I have a tank but if a lot of people want to do the saggar kiln, we might run out.

If you are interested in participating in the demonstrations, contact me at sjsartist@gmail.com. If you would like to do the studio tour go to http://onandofffred.org/catalog/ to purchase a catalog. The printed copy is $15 and the electronic version is $5. The catalog has the studio tour map and artist discriptions. Buying a copy helps keep this event free for artists to participate.