A Few Notes on Health and Safety

Teacup and Saucer, Arabesque Collection

After my last post, I was asked to comment on health and safety in the studio.

Let me start this discussion by stating outright that I am not a safety expert. Nor do I wish to portray myself as such. I'm just a girl who went to art school, and who makes her living making pots.

So, with the disclaimer out of the way, here's some general thoughts on health and safety in the studio when it comes to testing glazes:

There are ALWAYS risks associated with ceramic materials.  Some materials and their associated risks are well known in the ceramic world: silica dust for example, a basic ingredient in clays and glazes, is well know for its affect on your respiratory system over time. Other ingredients may pose risks that many people may be completely unaware of (cobalt, anyone?) and yet these ingredients are used all the time.

Ultimately, it is up to you to learn about the materials you are working with. What are the hazards associated with them? What level of risk do they pose? Are you equipped to deal with this material in your studio? Whenever you pick up a new material to work with in your glazes, ask for the MSDS sheets. These are available at any place where the ingredients are sold. They are also all over the internet. Do your homework. Any number of ceramic websites also have all kinds of information on the health and safety of ceramic materials.

That being said, some basics for studio safety include things like:

• Wear an appropriate respirator when mixing glazes. Yes, yes, I know. They are uncomfortable. It's hard to breathe in them. If you wear glasses, they can be especially cumbersome. But suck it up. Breathing is kinda important so don't mess with your lungs. 
• Keep your studio well ventilated - turn on an exhaust fan, open a window, get the air moving through and out of your studio. Not just when you are mixing glazes, or cleaning up after mixing glazes, but also while you are firing your kiln. 
• Use a kiln vent. Keep your kiln in a well ventilated room. Don't go in there during the firing, and wait until the air has cleared after the firing. If you can smell fumes while your kiln is firing, you shouldn't be in your studio. 
• Wear gloves when mixing glazes. Many ingredients cause contact dermatitis. Other ingredients can be absorbed into the skin, most of which you probably don't want in your body.
• Wear eye protection. Some materials can be absorbed through mucous membranes, which include your eyes.
• Use a wet sponge to wipe down tables and work surfaces, and mop your floors. It's important to keep dust levels down.
  

I have been providing information on the glazes that I am currently testing in my own studio. And these include ingredients that you may or may not want to bring into yours. It is up to you to decide if you want to work with these ingredients or not. And as for the glazes themselves, be aware of whether or not they are food safe. The tests I am currently doing are for decorative glazes that will not come in contact with food surfaces. If you want to use these glazes on food surfaces, you need to figure out if they are food safe or not, and even have them tested. If you have questions about specific recipes, ASK. If I can't provide answers, pose your question to any number of online ceramic forums.

Basically it all boils down to you. Take responsibility for your actions. Take responsibility for your work. Understand what you are working with. Take the appropriate safety measures. Educate yourself.

Here are some links to great articles regarding health and safety in the ceramic studio:

• Being Realistic about Toxicity and Safety in Ceramics
• Dealing with Dust in Ceramics
• Manganese Toxicity
• Overview of Material Safety
• Pregnancy and Ceramics

So. After having said all of that, please note the following:

• If you injure or poison yourself testing glazes in your own studio, it's not my fault.
• If you develop an allergic reaction or choke on dust or fumes, it's not my fault.
• if you break the space/time continuum and open up a portal to another dimension, IT'S NOT MY FAULT.

Bring On the Tests...

Okay.

So I've been working out some new ideas and need the glazes to make the pieces work. Given the excessive problems my pug mill has created, I have LOTS of seconds sitting on my bisque shelf. I always hang on to things that don't make it through the first firing - blow outs, cracks, serious warpage. These become great pieces for testing glazes and i have plenty for this round of testing. Based on the images in my sketch book, I've decided to just apply the glazes to these test pieces to give me a better idea of what I'm trying to achieve, rather than dipping tiles.

All of the tests are to go with my finicky slate matte glaze which I am far to stubborn to give up.

First the crackle recipe from my last post: I have a soft pink that I'm interested in working with which contains 10% erbium oxide, and need some other colors to compliment it. I tried some tests with a deep crimson stain and a blackberry wine stain, both from mason. Both came out mostly gray, with streaks of both burgundy and green. Incidentally, I also had an older batch of glaze I was testing the blackberry wine stain in that was specifically for use with red stains and even though it's not a crackle, I decided to throw it on some pots anyways.

I was also interested in working with some blues and greens in this crackle base but decided to leave those for now.

Okay. Wait. That's not entirely true. I tried a couple of tests: dark, rich blues from a combination of cobalt and manganese. But that led me to the realization that I need to spend some time in the paint department of my local hardware store to study blues together, since I intend on using the crackle blues with my sky blue glossy glaze.

For the green tests, I tried some praseodymium oxide in amounts of 7% and 10%. The 7% came out very soft, while the 10% pushed the glaze to a matte. Not quite what I'm after. I don't think.

As for the matte glazes I tested, I can tell you that a base with zinc does NOT like encapsulated stains. Gave me a very interesting frothing effect. Could be good on sculpture, but definitely not on dessert bowls. And the barium matte glaze did not give me the brights I was looking for either. The colors were way too soft.

I also tried out some black. I tried black underglaze both under, and in the crackle glaze, and another version of the same underglaze that I saturated with copper oxide for a metallic look. I also tried using the Licorice glaze from the Mastering Cone 6 book. This bucket had been sitting around for about 8 years. Just needed some water and a good sieving and it was ready to go.

So have a look. Here's what came out:

 

This first piece used the Licorice where I wanted the black. Clearly it didn't work so well, blended too well with the surrounding glazes. And see that froth? Interesting, no? Ummmm. Yeah. Not quite. You can also see the green/gray that was supposed to be a burgundy color. It's nice, but not what I'm after just now.

And then there's this piece:

So this piece is actually starting to go somewhere. The darker pink stripe is the blackberry wine glaze I mentioned earlier. The black pinstripes are black underglaze. The darker stripe is a  moss base glaze with about 5% blackberry wine in it. I had this bucket sitting around from tests I was doing a while ago. Again, I just decided to throw it on, since I had it around. I'm glad I did this because I think the colors all work well. The Arabesque lines are a black underglaze that I loaded up with copper. The results are actually quite metallic, but you can't really see from the photos.

So where to go next? Well, first a look at what I don't like about this piece. I feel like the decoration is more "stuck on" the side of the pot, rather than a part of it. I don't like that. Maybe some carving? I'm not sure but I'll work on it. So back to the testing and we'll see where things go!

In the Beginning...

And so it begins!

This is the first official post in a series of writings I will be doing on my approach to glaze testing and how it informs the development of my work. I have two separate things on the go right now, and this post will deal with the first one.

In the beginning comes the first hint of an idea. This is where my sketch book and a giant box of pencil crayons come in handy. My mind has been juggling several different things for a while now. First of all, I've been studying my new line of work and can't seem to shake the urge to draw flowers all over it. This is not new for me. I love pattern, and am very attracted to the idea of layering, with inspiration coming from both the fashion industry and fancy-schmancy wallpapers. So here's what my brain spits out:

A window of glossy stripes with a flower in the corner, to go with my slate matte glaze that I'm totally in love with despite all its flaws. But the longer I looked at this image, the more I realized it doesn't work. At all.

So the other thing that has been whirring around in my brain is how to combine the two, very distinct, lines of work that I have going on right now. So that got me thinking about adding some Arabesque lines rather than the flowers. And here's where that idea took me:

And:

Which then led to these:

And these:

These images got me rather excited so now begins to process of determining how to go about translating these images onto the clay. I'm pretty sure I want to go with some black underglaze, or maybe even some black glaze for the Arabesque lines and the pinstripes. As for the colored glazes, at this point I'm thinking maybe some kind of interesting matte glaze in the narrow stripes, and a crackle glaze in the wider stripes. The colors I'm interested in are a soft pink, maybe a burgundy, or Merlot color, a medium blue, and a vibrant turquoise for the crackle glaze. For the matte glaze, I'm interested in perhaps a lime green, an orange, or maybe even some crazy red.

Getting an idea of the colors I'm after will help determine what type of base glazes I want to start testing. As for the crackle glaze, I just happen to have a soft pink crackle that I had been using on Christmas ornaments, the color coming from erbium, one of the rare earth metals. As for the burgundy and Merlot, I'll definitely need to use stains. Okay. No problem there. But because of the nature of those colors, I need to make sure my base glaze is compatible with the stains to get the color I'm after. Enough calcium. Check. High in the alkaline department. Also check.

Here's the glaze recipe I'll start my testing with:
it's called Kittens Clear Gloss, attributed to Kathy King:

Nepheline Syenite: 30
Wollastonite: 8
Gerstley Borate: 21
EPK: 10
Flint: 31
Strontium Carbonate: 15

As for the mattes I'll try, I want something with more visual interest, not just a matte surface. I have a recipe called Val Cushing's Cry, which a dry, sparkly matte, and another recipe that's a stunning barium matte called Super Dry Matte.

Here's those recipes:

Val Cushing's Cry:
Silica: 10
Nepheline Syenite: 25
NC-4 Feldspar: 25
Zinc: 25
Titanium Dioxide: 5
Whiting: 10
(now even though this one has a bunch of zinc in it - which can be detrimental to colour - I figure I'd give it a try anyways. What can I say. I like the sparkles.)

Super Dry Matte:
Nepheline Syenite: 59.6
Barium Carbonate: 21.1
Calcined Kaolin: 7.7
Flint: 5.8
Lithium Carbonate: 5.8

I've obviously got a lot of tests to mix up. I have on hand some Blackberry Wine stain, some Deep Crimson stain, some praseodymium oxide, some orange stain, some crazy red stain, some cobalt, some copper and some chrome to get me started. So stay tuned! If you have any questions about the glazes, feel free to ask away!

A Peek Into my Creative Process

I recently finished teaching my first class on glazes. Specifically, how to mix and test different colorants in glazes. This is something that I have wanted to do for a while. The nerd in me has always enjoyed testing and manipulating glazes, and within my local pottery guild, I saw a need for help with this subject.

After testing 153 different color combinations in a single base glaze, the last class was by far my favorite. This was the class where I attempted to pull it all together for my students, and hoped to pass on the glazing bug. In putting together the notes for this last class, I got to thinking about where to take all this information. What did I want my students to go home with?


I sorted through 8 years of tiles from my own glaze testing to bring in some of my more interesting results in an attempt to show my students how to proceed. What I really noticed, was how well it demonstrated my own creative process. And rather than try and explain it, I may as well show you.

Over the next few blog posts, I'll show you what I've been up to, and where it's taking my work. I currently seem to be going in a few different directions so forgive me if the posts jump around. What can I say? There's no telling where my brain takes itself...

A Minor Victory, But Sweet None-the-less

Problems in ceramics tend not to surface until your full-on into production. Case in point: my slate matte glaze.

I love this glaze. I hung onto if for a year, working out how to use it in my work. When my glossy sky-blue glaze struck a chord with the slate matte, it was full steam ahead. Or so I thought. Most pieces were fine. Made it from start to finish with no problems. But anything taller, with straight-ish sides was a whole different ball of wax. I was losing anywhere from 50 to 95% of these pieces in each kiln load.
That's a lot of garbage to be making, and honestly, I can't afford to make trash.

The problem? Large pinholes, or what looks like blisters in the glaze that had popped, the edges healed, but the center remained bare clay. On the smaller of these pieces, like my tall cups, there would be one or two of these blisters. Enough to ruin the piece. Larger pieces, like my large vases, would be covered. COVERED in these blisters. Not a pretty site.

So where to begin?

There's any number of reasons why a glaze would do this, so I just started moving down the checklist trying to figure out what the hell was happening.

Perhaps some organics left in the bisque were causing the problems, but a higher bisque didn't help. Still got blisters.
Moving on, perhaps it was gases swirling in the kiln? I checked my kiln vent, adjusted it accordingly but that didn't seem to help either.

Okay.....

Next thought: water vapour. Thinking wet glazes were casuing problems, I let them dry before loading my kiln.
Nope. that didn't work either.

Okay. Maybe it's from overfiring the glaze? It only seemed to happen on these taller pieces, which also occupy the top shelf of my kiln. Cones indicated my kiln was firing evenly so I tried going from cone 6 down to cone 5. Boy did that ever make the glaze ugly and flat. And the blisters persisted.

With firing things ruled out, I moved on to the glaze recipe iteself. Was there something in there that could be causing this? I sent copies of it off to trusted glaze experts, but they didn't notice anything out of the ordinary. The EPK was a bit high, in the crawling range, but I wasn't experiencing any crawling, and even substituting some calcined kaolin for the some of the epk didn't solve my blister problem.

At this point I was beginning to believe it was an application problem. And I'm not set up for spraying glazes, so that wasn't even an option.

I moved on to glaze additives. First up was some CMC gum. Perhaps the glaze was drying too fast on the ware?
Nope. That didn't help and just made things messy.
Ugh.
Next was some Darvan and sodium silicate. I thought, what the hell, but that didn't work either.

Now it's important to point out that by this time, my husband just cringed whenever it was time for me to open the kiln. It's hard making work when you have orders and deadlines, and you have to throw most of it away. Many kiln openings were accompanied with cursing and/or tears. But I'm stubborn and I persisted.

Chatting with a fellow potter at a show, I asked him if he added anything to his bucket of matte glaze. The answer? Epsom salts. The same epsom salts that ruined my clay body. I tsp per 10kg batch of glaze.
And bloody hell, if it didn't work like a charm!

Epsom Salts, or magnesium sulfate, is a flocculant. These help prevent glazes from settling, which I didn't think my glaze needed since it had so much clay in it. But apparently they also help with glazes used for dipping or pouring. I had come to believe that air bubbles were being trapped against the surface of my bisqued pot when I dipped it, and that they couldn't escape until the glaze was melted. But being a matte, the glaze didn't flow enough to heal the surface like a glossy glaze would. The epsom salts create a porous surface in the raw glaze so perhaps its easier for those air bubbles to escape before the glaze melts?

At any rate, I guess there's a couple of lessons I take away here.
- Don't put out a line of pottery to my wholesale clients until I have worked with it thoroughly first, to try and spot any problems.
-Ask for help. I have no problems with this. Many times I'll get answers that I have already tried, but there's bound to be someone, somewhere, who's done something I haven't thought of.
- and most importantly, never give up! If you want to solve those problems, you have to keep plugging away at them. Now, it's better to do this if you don't have the pressure of HAVING to get things done by a certain date (see the first point) but perserverence pays off!

A few more new pieces...

As promised, here's a few more of the feltware pieces I've been working on.

Enjoy!

 

This is "Tea Anemone 2". The second in a series I am working on. I have found a way to make the tentacles look more twisty and bendy which I think gives them more character, but at the same time the photograph doesn't really do them any justice. It's hard to get a feel for their movement from one still shot. Otherwise, I'm happy with these pieces. The slate matte glaze makes a perfect neutral to contrast with the colored wool. More colors coming soon!

This work is a set of Nesting Anemone Bowls. I can tell you (as if it's not obvious) there is a LOT of tentacles there. A LOT. I would like to make more of these but we'll see. This particular one I have been working on since October. Yup. October.  I need to figure out how to expedite the anemone-making process for this type of piece. I think everything needs to go bigger but we'll see. The tentacles here are quite thin, which made it very difficult to add the pink tips.

At any rate, I'm having FUN.

Which is the most important part.

I have set aside one day a week for play time. No production allowed! So far it's been amazingly refreshing, but my production for the year really hasn't started yet so we'll see if I can keep it up.

My Latest Stuff...

Since my schedule is a little more open right now than I am used to this time of year, I've been working away on my Feltware Collection.

I was finally able to figure out how to consistently fit travel mug lids to my tall, feltware cups. Look for these at all my shows this year.

The lids are great too, they have a little tab that slides down to close the lid so your coffee doesn't spill and it actually works!

After the One of a Kind show this past December, my tall feltware cups were a huge hit, but some people asked for shorter cups that would fit in a coffee maker.
Well, ta da!

I'm so excited about these little guys! I've been using one myself just to take them for a test drive and I absolutely LOVE it!

I've got some more projects on the go including some custom cozies to fit my round bottomed tumblers so I'll keep you posted. In the meantime, I'll be posting these throughout the week on my etsy shop, so keep your eyes peeled!