Sonoran Arts Network
  • Home
  • Features
  • Interviews
  • Reviews
  • My Turn
  • Video
  • Editor's Page
  • About
My Turn
September 2015
Joy Holdread
Responsible Use of Ceramic Glazes


Picture

PictureJoy Holdread
I was raised to be resourceful and to abhor waste. I believe it is morally right not to waste the earth's resources, or thoughtlessly throw anything useful away. I loathe the amount of tax dollars we Americans waste on disposal systems and landfills that accommodate thoughtless gross consumerism and wasteful behavior patterns when our teachers are underpaid and schools are under-funded.

As a potter I've minimized my contribution of heavy metal and chemical contamination to the local water table, avoided the necessity of a studio sink, specialized drain trap, plumbing and septic tank problems, decreased the frequency of glaze ingredient purchasing, weighing and mixing.  I rinse my glaze brushes, sponge buckets, pouring containers, and I wipe down my vinyl work surface and rinse that sponge off in a bucket.  I let the chemicals settle pour off the excess water and run the chemicals through a screen to remove sponge hunks, dog hair, bits of bisque etc.  I dab a bit of this scrap glaze on a tile splash a bit of clear over half of the test  tile and my next firing will give me the results of my newest Scrap Glaze.  I label them by date.   By reclaiming glaze chemicals from the glazing process as well as making use of little dabs of glaze tests I keep lots of heavy metals out of waste water.  Remember we all live downstream from somewhere.

Years ago when I worked as a studio tech I watched my employer dump her glaze rinse water out under her trees and in her garden. I thought about gardening in the spring, inhaling those chemicals when we worked the garden soil and vegetables absorbing what was left in the soil. Not a nice thought. I talked her into letting the glaze materials settle and pouring off the excess water then testing the remaining new glaze. Her studio scrap glaze was consistently blue-green, probably due to the cobalt she used in her blue and black glazes. Soon every glaze screen, funnel and bucket along with our hands and all glaze spills were mopped up and rinsed in one bucket. Not only were we using less water but the bucket went wherever we worked, making less steps for us as we mixed, screened, glazed and washed up. Within a year we reclaimed more than five gallons of this beautiful sea-green glaze. Think of the time Saved NOT shopping for chemicals, weighing and mixing five gallons worth of glaze. (I personally dislike leaving the studio to shop for anything.) Think of the money Saved for the time shopping, weighing and mixing five gallons of glazes. Think of the money saved for five gallons of glaze chemicals or premixed glaze.

PictureScrap glaze test tiles
I know of three other methods for scrap glaze disposal, they all have their weak points.

1.) Allowing settled materials dry out and disposing of them at a hazardous waste location. Not all facilities will accept them, and I don't want to spend creative time playing chauffeur to waste materials.

2.) Letting the chemicals settle in a bucket, dry out then firing them in a bowl, to render them insoluble before disposing of them. Well we're still talking about disposal, the chemicals go to waste. We've used productive space in the kiln and the thought of a bowl full of melting glazes inside my kiln waiting to spill and drip over burners, kiln shelves, posts and over other pottery if the bowl holding the glazes ever breaks or leaks is an image that sends me screaming into the night. I don't care how many times other people have not experienced that disaster. I don't want to risk my kiln or kiln furniture.

3.) Throwing small amounts of scrap glazes in their next batch of clay. I'm much more careful with glaze chemicals and I wear a serious mask when I'm mixing glazes. I wipe up all glaze spills and do not generate much glaze dust. Sadly not so with clay. I wish I could make what I make and do what I do and not generate clay dust. I don't like the thought of glaze materials mixed with the clay that becomes dust in spite of my best studio cleaning methods.

I love testing these new scrap glazes with every firing. I often use multiple glazes swirled together for special pooling effects. Of course scrap glazes have limitations -- I don't know what the chemical composition is and I never use scrap glazes on the inside of any pottery that might contain food or drink.  I use my scrap glazes the outsides of pottery, and one of a kind sculptures. When the glaze is used up it's gone. I'd never consider using it on a production line that required consistency for re-orders.

Left over glaze tests or spilled chemicals are also a great source of scrap glazes. Additions of other chemicals can adjust the fluidity or matt qualities, added oxides can change the color. Clear glaze over scrap glazes often gives a completely different result. Very matt glazes can be used as slips.

Oxide stains can be reclaimed using the same method without the bother of a test tile.  I brush on dark slips, barnard, red art and oxides on bisque ware then wipe off the surface to emphasize the texture of much of my work. I use separate small buckets of water for each oxide to squeeze out and clean my sponges. These buckets settle out and I pour settled oxide or slip right back in the oxide or slip bucket.

My studio scrap glazes have ranged from ambers, browns, earth and sky, greens, and, blues.

I enjoy using them to add excitement to multi glazed forms or for the outsides of some of my vessels. I number the glaze containers and label the test tiles with the month/year/ and test number.

Try it, have fun, do the earth a favor.

See Joy Holdread's ceramics at http://www.holdreadart.com/



Sonoran Arts Network copyright 2013-2019

  • Home
  • Features
  • Interviews
  • Reviews
  • My Turn
  • Video
  • Editor's Page
  • About