October 12, 2001, Newsletter Issue #59: More Users Questions

Tip of the Week

Question:
Many years ago I bought some pottery and wallhanging that were made in a firing method called "racu." Problem is, I don`t know how to spell it. Do you?

Answer:
The method you refer to is Raku, it is a wonderful technique, very hands on: RAKU PROCESS Raku Pottery is earth derived...the firing process is unique and daring, and in the eyes of the Zen Masters, the process truly reflects the most fundamental rhythm of enlightened life. A once-fired, unglazed pot is first coated with a paste-like glazing material, and then, still relatively cool, is placed directly into a red-hot kiln (1,800º to 2,000º F) with steel tongs by the potters. It is this first tremendous heat shock which often causes a pot to explode or to develop large "body cracks" in the clay walls. If the vessel survives this shock, almost immediate metamorphosis begins. Within just minutes the entire vessel glows like red-hot coal, and the "glaze-paste" melts into a sheet of liquid glass. At this point, the pot must endure a second shock as the potter uses tongs to remove the glowing mass from the inferno. As the glowing vessel is hit by the cools air outside the kiln, the severe temperature change produces the cracks in the glaze. These cracks are highly prized as characteristic of traditional Raku Pottery -- they are the "proof-marks" of the earthenware´s having survived this dramatic trial by fire. Upon leaving the kiln, the glowing pot is placed directly into an airtight container ("reduction chamber") filled with leaves, pine needles, or the like, which turns the naked clay foot black and highlights the valuable cracks in the glaze. As if all this were not enough, when the colors are deemed "just right," the vessel (often still over 1,000º F) may then be plunged into cold water to halt the process. And so the cycle of earth, fire, air and water is complete. Raku is a daring process, and a great many pots do explode during some phase of the firing. These survived the ordeal -- the test of fire. May you be equally blessed... See this and many more interesting Raku facts on site: http://www.ceramics-tips.com In Firing, Articles, and History (the Tea Ceremony) I hope this has helped!

------------------------------------------------------------
Question:
Is it possible to recycle slip?

Answer:
Yes, it is possible to recycle slip, though not to the extent of clay. A limit of 10% used slip to 90% new is maximum. Be sure old slip is totally clean and free of plaster. Mix slip well, I suggest as well as a slip stirrer or mixer, you add some marbles as well. This does a great job. *happy potting*

------------------------------------------------------------

Question:
I am looking for a recipe to make homemade plaster. I looked at all of the craft sites. Is there any way you can get me a recipe to make plaster? I work at a daycare center and would love to do this with my pre-k class. Thank you,

Answer:
Your question is confusing. If you want to make plaster from scratch, I suggest you don´t, Potting Plaster is very hard to make and best left to those in the know. If, however, you want the recipe for mixing your own plaster from the bag, I can help! You will need potting plaster for molds, (it is stronger and finer). For a bucket of plaster you will need to fill the bucket to just under 2/3 water, then, wearing a mask, as plaster is toxic, consistantly shake in handfuls/containerfuls of plaster evenly over the water the plaster will fall and settle. When the plaster is forming islands, (i.e., lumps of grey surrounded by water), shake the plaster onto the water until all is absorbed and the top of the bucket is covered in plaster. Wait until all plaster has gone grey (there should by this time be no water), then stir with your hand, fingers slightly splayed, and move your wrist from side to side, in order to mix the plaster, (this eliminates air bubbles). When all the plaster has been dissolved it is ready to pour. Tap the bucket all around. If you have some air bubbles on top of the mix, either scum off with a paper towel or spray with a mix of water and metho 10%. Once the plaster is disolved, time is a crucial factor. You must get the bucket poured and rinsed within minutes. For this reason organisation is imperative. The plaster, once poured will heat, then it will cool, once cool it is ready to take from the mold. This is a wonderful exercise for children, stamps would be great for them, remembering, of course, their names, if used would have to be reflective. May I also suggest the slab Christmas decorations, these can also be adapted to photo frames, for something special, also the basic pinch pots, I find children have great success with these. Hope this has helped, feel free to ask anything else that will help you and your class. *Happy Potting*

About LifeTips

Now one of the top on-line publishers in the world, LifeTips offers tips to millions of monthly visitors. Our mission mission is to make your life smarter, better, faster and wiser. Expert writers earn dough for what they know. And exclusive sponsors in each niche topic help us make-it-all happen.

Not finding the advice and tips you need on this Ceramics Tip Site? Request a Tip Now!


Guru Spotlight
Tammi Reynolds