Wednesday, April 6, 2011

Let's talk about Stoneware Glazes, Baby!

Glazes can be either the most nerve racking, or the most joyous, icing on the cake part of ceramics. I have a love hate relationship with glazes… mostly one of hate. Besides learning how to fire a manual kiln, glazing has been one of the most headache inducing experiences of my short life in ceramics. You have Low fire glazes, high fire glazes, mid range glazes, under glazes, over glazes, stoneware glazes, porcelain glazes, and probably some specified formulas for earthware glazes. I’m going to be talking about Stoneware glazes, since it’s what I’ve primarily been using. *STONEWARE GLAZES: WHY THEY'RE A PAIN IN THE BUTT

  • Stoneware glazes are notorious for running when fired, so if you soak your piece, or if you pour too much glaze on your piece for too long when you are glazing, then chances are you’ll be chiseling your piece off a kiln shelf. This happened with a very ugly, pea soup green mug of mine. I should have just left it as a permanent fixture of profound glaze ugliness.

  • Stoneware pieces that have been bisque fired are extremely pourous and like to soak up glazes like an extra strength paper towel.

  • **For the lucky jerks who have pre-programmed settings on their kilns they don’t have to worry about this next part.**

  • Stoneware glazes usually will turn out much better if they soak in the kiln, or in other words, instead of just placing your kiln setter and running away, most personal glaze recipe authors recommend you keep the kiln on high for an extra 15 minutes, or even to an hour, so that the piece can make sure they reach the full potential of the glaze color.

  • The bad side: if you overfire you risk your pieces being pitted, cracked, crazed, or the glaze just melting off leaving blank rough spots on your pieces.

  • Stoneware glazes are some of the most durable glazes out there, and are used for more than just decoration pieces. Stoneware glazes can be used in baking dishes, drink-ware, and much more. ·

  • Stoneware glazes achieve some of the most spectacular designs and textures (besides crystallized glazes), with speckles here and there and mixed color combinations once fired. These aren’t your typical glazes that are used at the paint and bake ceramic stores in the mall.

  • · Did you mess up? Well, stoneware glazes are some of the easiest glazes to refire to try to achieve the color you were looking for.

  • · Stoneware glazes can be applied in multiple ways. They can be dipped, sprayed on, brushed on, sponged, stenciled… etc.

Unfortunately, I have a lot of bad stories when it comes to glaze rather than good ones to share, but by learning from my own mistakes, trying new things, and remembering some of the tips my teachers in the past have gave me, I think someday I’ll be one of those smug master potters you see at the craft fairs, all high on their horses, but they have reason to be proud, creative pottery is half the challenge, glazes are the other battle.

Here are two pictures of a test cup I wanted to test some glazes on. This was a prime example of how pourous stoneware bisque pieces can be in which the majority of my glaze was eaten into the piece during the firing, which is why the cobalt is so dull looking. The piece actually looks very close to a denim blue jean look. Perhaps, I've created something nice in my mistake? ;-) I should have double dipped this piece. My other mistake was a mixing mistake in which I was trying to mix a floating blue glaze on top of a cobaly blue. The floating blue obviously had some raw material that just wasn't working with the cobalt, so in return we get a rustic brown look. Far-FAR from the blue I imagined. Ah, Live and Learn. It's the official motto of pottery and ceramics.

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