Originally Posted on: Oct/05/2004 19:53
Mastering Runny Glazes
Many of us have recipes for glazes that we adore, but which run and ruin kiln shelving if we are not very careful. One solution to this problem has always been to wax a large foot onto the piece, giving the glaze a chance to move safely. This leaves a lot of unglazed clay at the bottom of the ware. Another solution, which takes more time but produces a more subtle effect, is to dip the bisqueware into clean water before glazing. Try this:
Wax a normal sized foot onto the piece. Then dip the bisqued piece up to the half-way mark in clean water and quickly remove. Wait 5 minutes. Now dip the piece one third of the way up into the water and remove. Wait 5 minutes again, and lastly dip the piece one quarter of the way up into the water and remove. Wait 15–20 minutes and glaze as usual. (You may have to experiment with the amount of time you let the piece dry, due to changes in humidity).
The portions of the bisque that have been soaked in water will absorb less of the glaze, gradually thinning it out towards the bottom of the piece, giving control and an unbroken effect.
WARNING: experiment w/ this technique on test pieces, and use tiles to protect your shelves until you get the hang of it. With a little practice, you will be a pro at controlling your unruly but gorgeous glazes.
Submitted by Susan Komanetsky
A flat tile of bisque ware placed under your piece can save a kiln shelf from a runny glaze gone wrong.
I keep a stack of simple flat bisqued tiles. If I am trying a new glaze, I find one about two inches wider than the base of my piece. The unglazed surfaces normally don't stick together, so if the glaze works, the piece is not harmed. But if the glaze runs, the tile is a life saver (well, shelf saver, anyway.)
I tried Susan's technique last quarter. Worked wonders! My pots are a bit thick - actually really thick - so too much glaze attaches to my pot and it runs. I had to let it dry about twice as long as Susan rec'd, but I think that is because of the fat walls. Thank you for the great idea!!!!!