clay Archives - Ceramicscapes

May 1, 2017May 1, 2017

Soda Firing Process

Last week, I participated in a soda firing at the Colorado Potters Guild. The soda firing process is a gas reduction type of firing and is fairly labor intensive as compared to a regular reduction firing and definitely easier than an electric or oxidation type kiln firing.

Soda Kiln is loaded - kiln packs are visible — Soda Kiln is loaded – kiln packs are visible

Soda Firing Process

“In the soda firing process, soda ash (sodium carbonate) in water solution, is sprayed into kiln at maturing temperature, and sodium vapor combines with silica in clay to form sodium-silicate glaze.” – excerpted from Ceramic Arts Daily. It’s a magical process and I’m addicted to the outcome.

My firing partners and I spray the soda ash solution into the kiln ports when cone 9’s have fallen. Cone 9 is the equivalent of 2300 degrees F. We have 2 visible cone packs in the front bottom and top of the kiln. While we have a pyrometer to measure the temperature, we use the cone packs for visual confirmation of the kiln’s temperature. After the soda ash container is empty, we shut down the kiln and plug all the ports and burners. Once the kiln has cooled down so that pots can be handled with bare hands, we unload the kiln. We fired on Thursday and unloaded on Sunday, though, we probably could have unloaded on Saturday.

Wadding

After the soda ash is sprayed in the kiln at maturation, there is a fine layer of sodium silicate glaze over the interior of the kiln and on the kiln shelves. For this reason, we add little clay/alumina wads to the bottoms of our pots so that they do not stick to the kiln shelves. The wadding recipe contains 50% alumina which does not stick to the pots or the kiln shelves.

The wads to leave little circular marks on the pots which are the sign of a soda, salt or wood fired pot.

Soda Firing Adding Wadding to the bottom of each pot

Post Firing Clean Up

After unloading the soda kiln, clean up begins. We use silicone carbide scrapers to scrape the glaze off all the shelves and posts. It’s a huge job, but one that goes fairly quick between 4-5 people. We had 5 people in this last firing and were able to unload and clean up in two hours time. Clean up is dirty work – with silica dust flying wildly. We use safe practices and all wear respirators and eye protection.

Below is a gallery of images if you would like to see more of our process.

2 Soda Firing Adding Wadding to the bottom of each pot

3 Soda Firing Adding Wadding to the bottom of each pot

4 - Soda Firing Pots Are Ready to be Loaded in the Kiln

5 - Soda Firing Process - Wendy and Kathleen — 5 – Soda Firing Process – Wendy and Kathleen

6 - Soda Firing Process - Sarah sits inside the kiln and arranges pots, shelves and posts — 6 – Soda Firing Process – Sarah sits inside the kiln and arranges pots, shelves and posts

7 - Soda Firing Process - The Back of the Kiln is Loaded — 7 – Soda Firing Process – The Back of the Kiln is Loaded

8 - Soda Firing Process - Close up of loaded pots — 8 – Soda Firing Process – Close up of loaded pots

9 - Soda Kiln is loaded - kiln packs are visible — 9 – Soda Kiln is loaded – kiln packs are visible

10 - Soda Firing Process - Kathleen and Wendy Spraying Soda in the Kiln — 10 – Soda Firing Process – Kathleen and Wendy Spraying Soda in the Kiln

11 - Soda Firing Process - Opening the Kiln to Reveal the Finished Pots — 11 – Soda Firing Process – Opening the Kiln to Reveal the Finished Pots

12 - Soda Firing Process - Close Up of Fired Pots — 12 – Soda Firing Process – Close Up of Fired Pots

13 - Soda Firing Process - After Unloading, wadding and the Fine Layer of Glaze Needs to be Cleaned — 13 – Soda Firing Process – After Unloading, wadding and the Fine Layer of Glaze Needs to be Cleaned

14 - Soda Firing Process - Kathleen Scraping Shelves — 14 – Soda Firing Process – Kathleen Scraping Shelves

15 - Soda Firing Process - Cleaning Shelves — 15 – Soda Firing Process – Cleaning Shelves

16 - Soda Firing Process - Cleaning and Scraping Kiln Posts — 16 – Soda Firing Process – Cleaning and Scraping Kiln Posts

17 - Soda Firing Process - Cleaning and Scraping Kiln Posts — 17 – Soda Firing Process – Cleaning and Scraping Kiln Posts

18 - Soda Firing Process - Cleaning the Inside of the Kiln — 18 – Soda Firing Process – Cleaning the Inside of the Kiln

19 - Soda Firing - Some of My Finished Pots — 19 – Soda Firing – Some of My Finished Pots

20 - Soda Firing - Some of My Finished Pots — 20 – Soda Firing – Some of My Finished Pots

March 27, 2017

Truncated Cone Template for Hand Builders

I do my fair share of hand building with clay. In fact, my first successes in my ceramics 101 class were because I learned how to hand build using slabs of clay. Success on the pottery wheel came much later.

I’m gearing up for my next soda firing at the guild towards the end of April and will be hand building mugs, bowls and other functional pottery. Paper templates are an easy way to achieve a uniformity in size and shape for hand builders.

I’ve made my own cup templates in the past, but in the interest of time, I decided to peruse Pinterest for templates. Low and behold, I found an online template maker – specifically a truncated cone template that is helpful for hand builders interested in making tapered cups of all sizes.

Why?

I already have a tumbler sized template ready to go, but would like to add some wine/juice cup sized ones. Also, I like drinking wine out of a handmade cup and, frankly I’m too lazy to do the math and draw it by hand.

Collection of Handmade Pottery Wine Cups — A sample of part of my collection of handmade pottery wine cups

The makers of the cups in the photo above are clockwise, starting with the light green cup – an old one of mine, Dick Howell, Michael Kline, Kathleen Laurie, Kristin Gruenberger and Jackie Harper.

What I like about this template, even though the site really caters to paper crafts, is that it’s scalable. Users need only enter their desired measurements for the bottom and top diameters and the height in either inches or centimeters.

Here is my wine/juice sized truncated cone template for hand builders:

Truncated Cone Template for Hand Building - Wine or Juice Cup Template — Truncated Cone Template for Hand Building – Wine or Juice Cup Template

My template measures 2.5″ in diameter at the base, 3″ up top and 4″ high.

Considerations:

The only tricky parts that users need to account for are how to print a template and clay shrinkage.

Larger templates will not likely fit on an 8.5″ x 11″ letter sized piece of paper, so you will need to either bring it to a printing company like Kinkos or print it out on multiple pieces of paper and piece together.

I guesstimated a reasonable size for my truncated cone template. Originally, I plugged in measurements of 3″(base) x 4″(top) x 4″(height) which was more of a small sized mug. I printed and cut the template out to check if the size works. After printing my first one, I downsized my measurements to 2.5″(b) x 3″(t) x 4″(h). This seems just about right for wine or juice.

I’m not concerned with volume at this point. I just want to make a cup that will hold about 4-5 ounces of liquid. If you are working on a custom order for a shop or gallery, however, you will need to do a bit of math (or use an online calculator) and also understand your clay shrinkage if a specific size is requested.

For further reading, the LaPellas, who I interviewed for Feature Fridays, have an easy clay ruler tutorial on their blog. Or, if you know your clay body’s shrinkage, you need to take this into account to make a template that accounts for your clay body’s shrinkage.

Finishing details:

I like to laminate my templates with packing tape so that I can reuse them over and over. They’re water resistant and won’t warp or buckle after placing it on damp clay. Simply cover the front and back of the paper template with packing tape, being careful to overlap the tap about 1/8″. Trim the excess tape from the template afterwards.

Stay tuned for a tutorial on my hand building process.

March 23, 2015

New Direction and Creative Explorations

Getting ready to carve rubber stamps — Mixing it up

Shortly after New Years, I didn’t have much going on in the studio…it was quiet after the holidays and a couple of online classes popped up on my radar and I thought, “Why not?”

I signed up for Molly Hatch’s/Ben Carter’s “Think Big” class and enrolled in Diana Fayt’s “The Clayer – Surfacing” class which ran concurrently for a bit. Why? I had been humming along just fine, but felt a bit bored creatively towards the end of 2014 and decided that learning something new would be a good jump start for the new year – a way to make some creative leaps with external motivation in the form of a class. I had already started the process of mixing things up in the studio, but then stalled once the holidays crept up.

I’m typically the type of person that jumps in head first and gives 110% to whatever it is I’m doing. It was no different for these e-courses. Emotionally, I was all over the place in the Think Big class. We were asked to do some real soul searching about the direction we wanted to move towards creatively, spiritually and financially. I am really inspired by Molly Hatch’s multi-faceted career as a maker and designer and I always look forward to Ben Carter’s interviews with “artists and culture makers” on The Tales of a Red Clay Rambler. At first, I didn’t think that I was interested in expanding outside of clay, but now I’m rethinking the possibilities.

I have always been a Jill of all trades, mistress of none. Yet, I have worked hard to focus on clay in the past two years in an effort to craft a career in ceramics. I have not dabbled in other mediums – I have concentrated on clay. The effort has not been for naught. I lost momentum in 2009 when I decided to go to graduate school for landscape architecture. I returned to clay in earnest late 2013. I also returned to making and working like I used to do before taking a clay sabbatical. In essence, I found it necessary to relearn how to work with the material, to understand the work flow, the making cycle and more. Going back to what I knew was easy. Switching gears is hard, but I’ve done my homework.

Graduate school was both a blessing and a curse for me. I loved stretching myself mentally and physically – accomplishing things that I never thought possible. It was a bust in that I adopted a more contemporary aesthetic that wasn’t totally authentic to me and I decided that I didn’t want to practice landscape architecture. The gifts that graduate school gave me are endurance, thick skin, humility and an ability to think bigger. Did I need to go to school to learn that? Probably not, but I can’t change the past.

Making handmade rubber stamps and testing on paper

The Clayer – Surfacing class was great! Diana is a fantastic instructor and was very encouraging to everyone. I wasn’t sure if I was interested in many of the techniques that she was teaching, but I love her work and have followed her on social media for years. We were given assignments every week and shared our efforts with each other and sometimes the world via social media. I have learned that I like Mishima (or the art of slip inlay) as a technique. I love creating my own patterns through the use of hand carved rubber stamps. Mono-printing on clay is cool. AND I really like hand building with clay.

I found joy again in creating, trying new things and working in multiple mediums. It was almost as if I were given permission to play and to go back to what I was doing before I went to graduate school. It’s the freedom to do what I want with no expectation of a particular outcome. I also know that I am throwing my whole business plan out of the window.

Working out ideas on paper - seeing how they translate to a 3 dimensional object — Working out ideas on paper – seeing how they translate to a 3 dimensional object

Between these two classes, I have discovered that I actually have something to say and that I want to share these creative explorations out loud. Instagram, Twitter and Facebook just don’t have enough space to delve deeper.