Glazing – Page 12 – Joel Cherrico Pottery

14 March, 201415 February, 2017

Ogres, Princesses, and Pretty Blue Glazes

I remember the first time glazing a pot in Sam Johnson’s ceramics class last year. I had made this slightly uneven coil vase with pockmarked walls nearly an inch thick. The piece was truly ugly, an ogre really, but I couldn’t see the pot as anything other than beautiful. It was my Princess Fiona and I was its Shrek…At least until I glazed it.

Like most naive ceramics students, I pictured glazing just like painting. I picked out a handful of colors using the test tiles as my guide, and then brushed swooping glaze patterns all over my vase. By the time I finished, the pot looked like something straight out a kindergarten arts and crafts class. I on the other hand thought it was a masterpiece – a trophy of abstract art. When the thing (it was beyond a pot at this point) finally came out of the kiln, it was hideous. I looked over at my professor for encouragement. Sam walked over, took one look at my monster, turned to the class and said:

“Opening a kiln can be like Christmas or Halloween. Either the pots look amazing and you fall in love, or the results are horrible and you want to smash everything.”

Kiln Loading 2 — The moment of truth, loading a kiln of glazed pots.

Unlike my great clay ogre, Joel can’t afford to make ugly pots. He makes his living through pottery, and as a result, his experiments with glaze need to be calculated and precise. He needs to know exactly how each part of the glaze works; how copper, cobalt, and iron make red, blue, and rust colors when the glaze reacts with fire in the kiln. Glazes transform clay bodies from ogres into princesses. However, as Joel continues to explore glaze chemistry, he finds that these potions are often difficult to create. Like the alchemists I wrote about last post, Joel works tirelessly to find the right balance of form and color that’ll turn a clay body into a beautiful work of art. For his livelihood, each glaze must reach for a certain standard of beauty.

Glaze Notes — – Studying past glaze recipes, tweaking the ingredients to make more alluring pots.

Looking back at his previous body of work, I think Joel’s been chasing this certain type of beauty all along. It’s been hidden in his work throughout the years, and now I feel we’re just starting to uncover it in the color blue.

Take a look at the gallery below to see an evolution of this blue color. Even in woodfiring, salt firing and copper red glazes, the color blue shows up. I can track the color throughout his work back to 2008:

2008, Oceanscape Cups 2009, Mindscape

Copper Red Glazes, Salt and REduction Fired, Joel Cherrico Pottery

2011 planter and jar, Cherrico Pottery

Collaboration with Bruno Press

Numerous potters talk about the lore of blue pottery. Throughout the ages, potters can’t seem to shy away from it. I’ve heard some contemporary potters even refer to the color as cash-flow blue.

Our text book this semester has been Bernard Leach’s A Potter’s Book. Now a 50 year old text, Leach provides a rich history of how ceramics has evolved. His book not only offers rich lessons of the past, but it also gives insights into the future. But even Leach, who wrote the book after decades of experience under his belt, could not seem to understand the lure of the color blue in ceramics. These stories share his experiences with blue glazes:

“At my St. Ives workshop each summer we are asked by three visitors out of four for colour and yet more colour, blue and the more intense the better, is easily the favourite.”

– A Potter’s Book, page 36

“Yesterday we had a good bunch of people, 2 of whom at least knew a good pot when they saw it. One woman started by asking if we hadn’t got any ‘blue pots’, and when David showed them that the last olive-blue glaze for which we have experimented for years, she said: ‘Oh! Do you call that blue?'”

– A Potter’s Book, page 227-228

Perhaps what this all boils down to is something we talked about in the beginning -the pursuit of beauty. Some of the best potters in the contemporary art world don’t make beautiful work. Their work is strange, ugly and confusing.

With this in mind, does the color blue still have a place in the contemporary ceramic world? This poster sits above our workspace, and it’s made from postcards Joel picked up in Philadelphia in 2010 at NCECA (National Council for Education for the Ceramic Arts). It gives a snapshot of the contemporary ceramic work, and shows only a handful of simple, blue pots. Joel will be at the conference in Milwaukee next week networking with contemporary potters and pottery enthusiasts. His goal is to show that the color blue continues to have a strong lure in both historical pottery as well as contemporary ceramics. He wants his work to be a bridge between historical potters like Leach and contemporary artists like Paige Dansinger. As a result, we’ve prepared some innovative market ideas, re-designed the website home page, and packed the online store with blue pots and artist collaborations with Dansinger. We’re prepared for the biggest ceramics conference in the country and we’re hoping to lure people to us with our blue pots!

Joel Cherrico Pottery Marketing Ideas, 2014 Joel Cherrico Pottery Business Card Coins

Joel Cherrico Pottery, Shot Cups, Innovative Marketing

Bernard Leach, A Potters Book, Beautiful Pottery, Joel Cherrico Pottery, 2014 — Bernard Leach, “A Potter’s Book” (Page 7)

21 February, 201423 February, 2014

Glaze Chemistry and Alchemy

Pottery Alchemy, Alchemy Definition, Joel Cherrico Pottery, 2013 — The New World Dictionary, Copyright 1967

In many ways, the work of the modern potter mirrors the work of the ancient alchemist. Potters blend earthly materials like clay, stone, and ash, into complicated glaze mixtures. Then through fire, these base substances transform into precious works of art. With glaze chemistry, and one part modern alchemy, potters turn the natural elements we once took for granted into the treasured artifacts we display in our homes and galleries.

It’s interesting to see how much the glazing, alchemy, and human life relate to each other. Bernard Leach, author of A Potter’s Book, helps us understand glazes by relating them to the body. He says most glazes have 3 main parts -the blood, bone, and flesh. Here’s how they work:

1.) Fluxing agent or “life blood of the glaze” – causes the glaze materials to melt and flow together in the kiln firing.

2.) Refractory or “bone of the glaze” – resists heat and melting, providing structure and strength to the glaze body.

3.) Glass Former or “flesh of the glaze” – creates complexity, depth and unique qualities.

(page 133-134)

Similar to Bernard Leach, the early alchemists fused their chemical efforts with the body. Calling their experiments the Magnum Opus, or “Great Work,” these men searched tirelessly for the right chemical concoctions that would enrich life or prevent death. In some ways, full-time potters do the same through glaze chemistry. They are constantly searching for that perfect potion that will immortalize a clay body and turn sand, water, and ash into gold.

These 2 books, by potters John Britt and Phil Rogers, gave Joel the necessary skills to develop that perfect glaze surface, but like the early alchemists, he’s still searching.

Like alchemy, glazing is often a fiery, messy, and sometimes toxic process. The kiln releases CO2, the powdered glaze materials are dangerous inhalants, and the heavy metal colorants cause skin irritation. Joel mixes all his glazing in an old boat shed. This dirty, dark laboratory gives him 24 hour access to glaze experimentation, providing the perfect amount of chaos to create beautiful works.

Joel’s pottery has to be strong enough to be used in a coffee shop everyday. The Local Blend Baristas say they wash a mug up to 5 times per day, 7 days per week! With this in mind, Joel adapted the Nuka glaze to suit the stress. Traditionally a simple 3-ingredient mixture, Joel added more chemicals to strengthen the glaze surface, reducing flaws like pinholes and crazing while increasing durability and gloss. Here’s the recipe for all the curious potters out there:

Some potters spend their careers trying to find the right glaze mixtures. In next Friday’s post, we’ll delve into some of these mixtures more and explore the lure of pretty blue pottery.

Cobalt-based glazes, or what some potters call “cash-flow” blue glazes, have been mystifying both potters and customers for decades.

“At my St. Ives workshop each summer we are asked by three visitors out of four for colour and yet more colour, blue and the more intense the better, is easily the favourite.”

– A Potter’s Book, Bernard Leach, page 36

11 August, 201115 February, 2017

Glaze testing at JD Jorgenson Pottery

I’ve spent the past week and a half firing the small gas kiln at JD Jorgenson Pottery, in order to accomplish a couple things with the Nuka glaze. At the St. Ben’s ceramics studio, I fired the glaze to cone 12 flat, almost cone 13 (about 2410 degrees F). At these temperatures, it takes a long time and huge amount of energy to raise even a single degree. It’s also harder on the kiln, shelves, and clay so it made a lot of sense to try and lower the temperature of the Nuka glaze before my new body of work.

The kiln at JD’s place was made from the shell of an old electric kiln that I salvaged from a high school in Sartell, MN. They kept the electric box, so JD cut 2 small holes in the bottom of the soft brick to make burner ports. Firing with gas instead of electricity will also let us test reduction firings very similarly to larger gas kilns. These practice firings willhelp me for adapting to the Paramount Arts Center gas kiln, which I’m firing for the first time this Monday. Fresh pots should be out by Art in Bayfront Park the next weekend in Duluth!

My first firing in this kiln was actually the second time JD fired it, and we got some really nice results. The glaze fluxed out pretty well at cone 10 (that was our goal) but the bottom of the kiln only reached cone 9. Also, even at cone 10 there were bubbles present in the glaze. The Nuka contains wood ashes, which are high in alkali. Something about the alkali cause bubbling in the glaze at high temperature, and the finished pottery had sharp holes and pits. Problems like this are common when working with earthen materials, but the struggle is well worth the rustic tones and philosophies behind working from a waste stream system.

Here’s a few finished pots from the 2nd kiln firing, as well as some underfired ones. The pieces on top are almost perfect, except for the bubbling where the glaze pooled.

JD and I learned a lot from these pots, but with a 22 hour firing into the night I wasted a lot of time and energy with the stalled out kiln. The barometric pressure changes every night, and this generally makes it difficult to gain temperature. Once the sun went down, we were at the mercy of the kiln to go at it’s own pace. Night firing makes for some cool pictures, but a miserable next morning.

Right now I’m in the middle of the 3rd firing and the kiln is at cone 5 (almost 2200 degrees F). Once it gets to cone 10, I plan to soak for at least 2 hours, so the bubbles will pop and the glaze will seal over. At 6 hours in, we’re really close to peak temp and the soak period so things are looking good…definitely better than another firing into the weee hours of the morning uuhg…and hopefully the pots will turn out looking close to this good!