Soda Glaze Gallery from RCS Corona Kiln!

This Glaze Gallery is meant to help Soda-Fire Workshop participants prep and aim toward desired results. Soda firing is experimental and unpredictable, but it’s still fun to set a goal and see if it happens.

What cone do you fire to?
We fire to Cone 6, so a midrange clay body would likely be best. Some areas of the kiln get hotter than cone six, so we recommend a clay body that doesn’t slump much at cone 5 or 6. In all experimental firing, playing with a variety will give more chances for success. Don’t put all your eggs in one basket. It is highly recommended that you experiment with slips, flashing slips, underglazes, and varied clay bodies in the soda kiln. Below is a gallery to learn from!

Atmosphere of the kiln?
The amount of oxygen in the kiln plays a big part in our firing results. We are aiming toward a neutral to lightly reduced atmosphere in the kiln. This will result in flashing on the work and small amounts of carbon trapping. This type of firing also allows for the preservation of underglaze color (where it is not hit by too much soda) and bright colors. Some glazes with copper will blush red or pink, but we still retail greens, as seen below.

What does Soda Do?
The soda will act as a clear glaze on the bare clay as it is sprayed into the kiln at peak temperature. It can be a very thin covering or thicker depending on where the pot is in the kiln. The soda will also affect the glazes that are on the pots. Usually, it melts them where it hits them the most.

If you feel unsure about what to try, consider a matte glaze, just underglaze decoration, or just sip decoration on the outside of the pot. Or feel free to leave your pot bare clay. Adding an interior/ liner glaze can be good. As usual, we suggest a shiny interior glaze (or studio clear - Robust Clear - does well in the soda kiln in more vertical pieces like cups. On a plate, it will be likely to craze if it gets a lot of soda.

Cone 6 Clay Bodies, Please try out any cone 6 clay bodies in the soda firing or clays covered with slips!

Please try out any cone 6 clay bodies you would like.

• Porcelain’s or very light clay bodies:
  Clay bodies with less iron, flash very softly (peach, tan, cream)
  We have had great results with Highwater Helios Porcelain, CAC Whitestone, Laguna BMix, (very light peach flashing)

• Light Stonewares
  CAC BC6, SPS Vashon Buff, CAC Idaho Buff, SPS Klamath Buff,

• Darker/ Iron Rich Clay Bodies
  SPS Fools Gold, CAC Oregon Red, & CAC Dakota Red (slip).

Slips are essentially watered-down clay bodies that can be brushed on at the greenware stage. Slips are often applied at the greenware stage. 

Flashing Slips are clay mixed with enough flux to help it stick on the pot. It often mixed thinner than a glaze and is often dipped on. They are put on at the greenware or bisque ware stage. When put on bisque, the thickness can be very touchy. If flashing slips are too think they will peel off. 

Carbon Trapping:
RCS fires in light reduction to a neutral atmosphere. There may be small amounts of carbon trapping.

What happens to underglazes in Soda-Firings?
The soda creates a light sheen on the surface when there is a smaller amount of soda and a lightly bumpy texture, like the peel of a citrus, where there is more soda. The more soda, the more glossy the surface in most cases.

Where the soda hits the underglaze it can wash it out. The soda hit 13.) the most on the right side where you see the “orange peel” texture. On 14.) the cylinder was hit by soda more on the left and that is where the red underglaze is more pink or even white. Cup 15.) has the soda hitting most right on the hat of the cowgirl. You can see the lightening of the color right on the upper edge of the cup.

Are there special glazes for the soda kiln?
Glazes can react beautifully to soda. Some melt more or get shiny where the soda hits. Some do not react at all. Here are a few that look great! Some of these glazes are available for participants in workshops to use.

Variety is key. Think about trying these combs on your pots:

• underglaze on clay with no glaze

• different underglazes, then waxed patterns and some glaze

• different clays with no glaze

• different clays with waxed patterns and some glaze

• different clays with oxide/colorant wash all over

• different clays with waxed patterns and some oxide/colorant washes

• Some pots that are all glazed

• Some bare pots with glaze accents

• Inlaid underglaze or slips

• Washes of colorants or underglazes

• And more!

How can we prepare for our glazing day?
You may bring your bisque pots completely bare to the workshop.
If you want to get a head start consider these options.

• Sketch a few ideas ahead of time based on the results in this gallery.

• You are welcome to line your pots at home if you would like to. You may do as much ahead of time as you would like.  It might be fun to try a few of our glazes also. Liner glazes are pretty straightforward forward : )

• It helps to wax the bottoms ahead of time.

• Wax patterns on bare clay. This can be helpful to do ahead of time too.
  This gives the wax more time to dry before dipping.

• Try out under-glazing pots at home. Especially if you have intricate surfaces, this could be a good option.