Questions & Answers
Here are some questions some of the visitors to my site have asked via email, and my response to them. If you have questions about my work, email me. I will try to respond ASAP.
Thank you, Ken
On Jul 28, 2013, at 6:18 AM, Jim Ginavan wrote:
Thanks so much for sharing. Your website is quite informative but I do have one question. When aluminum foil sagger firing. Do you allow the work to cool completely in the kiln or do you remove at a certain temperature to remove the foil and introduce oxygen to the piece?
Thanks again for your insight! I have found this process to be very exciting. I have a tendency to learn how to do something and then start to play the what if game with it. What if i did this or this to the work. Did that with my evolution of drawing and printmaking... only seams natural to carry that into ceramics.
Jim,Chances are pretty good that oxygen is getting to the work in most cases as the foil splits, turns to ash etc. If the foil is still silver and completely intact then it probably didn't get hot enough. You'll still get results but they could be better as the chemical salts become more volatile by 1400 F.I've pulled and opened work very hot to do horsehair technique, and just to get another firing done when time is an issue. I see no difference in the final work. When pulling hot, it's exciting to see the color development occur as the work cools, but be confident your clay body will handle the thermal shock.
I love that game! We can't help ourselves, as teachers, artist, designers, craftsmen and explorers, we have to ask those questions and experiment with different materials . The discoveries we make generate new questions and and help advance our artwork to new, exciting and interesting levels.
I had such a discovery that night, trying something I had been thinking about for quite some time and something else altogether different that just dawned on me at the time with really exciting outcome. I can't wait to share this new technique at the Potters Council in Oct.
Good luck & be fearless in your exploration,
I was contacted by Alexander Kostrikov, Laboratory for Comparative Planetology, Vernadsky Institute, Moscow, Russia, Via the Internet and asked to perform some small test for him in the interest of science. Alexander requested I throw a plate, promote "S" cracks, document with photos and share the results with him. We had limited correspondence but were successful with the experiments and the details. My tests helped Mr. Kostrkov to prove his theory that spirals in the North polar cap of Mars are evidence of an ancient Ice sheet collapse.
Alexander presented his findings to planetological conferences and sent me his abstract. If you would like to read it click the link below.
May Be You Can Help!
"I did not publish my paper in a scientific journal yet, but put its abstract (the text I sent you) in Internet. The problem is to provide a professional mathematical (computer) modelling of cracking in rotating body. (It seems this is a 'terra incognita'!) I am looking for a specialist now. So, you struck home. Maybe a ceramic scientist will be interested in this problem."
Link to A. A. Kostrikov's Abstract
A High school student emailed and asked for an interview for his part of his class project. I invited him to my studio, had a nice visit with he and his mother and answered his questions online. Click here if you would like to read it.
Beth, from Texas writes:
Thanks for writing back! Have you heard of James Watkins? He uses a certain raku glaze that we have been trying to duplicate: 80/20. We can't quite get it. Do you have any suggestions? We'd appreciate the help. Thanks!
80/20 is a very old and reliable raku glaze formulated by, or credited to Paul Soldner. 80% gerstly borate, 20% Neph. Sy. Many other raku glazes have been created using this base and adding coloring oxides, like Copper Penny, and Copper Sand. And sometimes slight variations of this base are used. The 80/20 is a beautiful clear crackle. Try using it on a white clay body or on a clay body with a white Tara sig. or porcelain slip. The key to achieving a good crackle is to remove the pot from the kiln and have great patients before placing it into your combustible material. You must listen carefully for the crazing to begin. If you want finer crackle patterns you can blow on the surface. If you are still not getting crackle, then you must change your clay body. The clay and glaze are compatible, this dose happen but not often. I fire to cone 06 this works well for me, even as low as 08 for some glazes and desired glaze effects, but never over 05 with the glazes I use. Also you must find that happy medium where you get the desired amount of crackle but the pot has not cooled so much that it will not ignite the combustible (I use news paper) if this happens be ready with a torch! The crackle will show up but the intensity will not be there. The first cracks will be the largest ones, they should be very black. a smaller network of crazing will appear with a lighter black and a third very fine network will be a very light gray. You may also see an even finer pattern show up later but it will not be smoked. These large to small, black to clear crazes add depth to the surface of your work, and make for a very rich and interesting piece. James Watkens, the name rings a bell but I can't place his work. I'll look him up when I get the chance. By the way, the raku bottle in The Gallery on my site (2nd to last photo) is 80/20. White stoneware with porcelain slip. Good luck with the raku and let me know when the site is up!
PS. You may already know they have stopped mining Gerstly borate and the supplies have been depleted. There are substitutions on the market (Laguna Borate, Cadie Cal, Murray's Borate), to name a few, but much testing must be done for glazes containing high amounts of GB.
Thank you for the information on 80/20! If it's not too much to ask, what glaze did you use inside of your "Ritual Bowl," the last picture in your gallery photos? It's beautiful!
Thank you, the glaze is called "Dolphin Blue", it's published in Robert Pipenburg's book RAKU POTTERY, Buy the book it's the Rakuists bible! Measure parts by volume: 7 - Gerstley Borate 3 - Bone Ash 2 - Neph. Sy. 1 - Cornwall stone 1 - Copper carb. 3/4 - Cobalt oxide This is always a beautiful glaze. The Spirit Bowl or Ritual Bowl is porcelain.
Ray, from San Antonio Collage, CA, writes:
My name is Ray and I have a paper to write. I chose a your Fertility Plate to write my paper on. So if you could answer a few questions for me I would greatly appreciate it. 1. What sort of precious metals did you use for this particular piece? 2. What inspired you to do this piece? 3. What does it mean? 4. How much does this piece cost? 5. How long did it take you to complete the piece? I can't think of any other questions to ask but if you have more information that you can give me about the piece I would greatly appreciate it. Thank you very much for you time and help.
Hi Ray, I'm glad you have an interest in my work. You have some good questions. My answers will be as short as I can make them because I don't type fast and must get to the studio. I use a product produced by Engelhard Hanovia called Liquid Bright Platinum and Liquid Bright N Gold 11%. The metals are suspended in an oil based solution, when fired at a very low temp. (1341 F) the organic matter burns off leaving a very thin coating of gold fused to the surface. Hanovia claims the gold is 23K purity.
I am inspired by the things I find beautiful and enjoyable in life. The "Fertility Plate" draws parallels between the creation of life, life giving forces, and the creation of in-adamant objects. Man's need to reproduce and his need to be creative are, I believe very closely related, if not one in the same. What dose it mean to you? Once I have created the piece and let it go, it becomes more important to me how those who come in contact with the work, interpret it and feel about it them selves.
The two plates you see in The Gallery on my site are 22" dia. and 26"dia. I've been working with clay for 27 years. That plus a few hours is what it takes for me to create one of these platters. The loss rate is also very high with these larger platters.
Good Luck, Ken
Hi Ken, I have a question for you on the silver and gold that you fire on your pots. If I fire a raku glaze on to a pot and I want to add gold to the pot after the raku firing will I loose my raku colors when I electric fire to the proper cone temp for the gold highlights . The gold is not as high a temp but 1200 to 1300 may change the raku glaze as well am I right. HELP!!!!!!! Julie
Hi Julie,Yes, you are most certainly correct. Firing the gold onto the surface of a raku pot will most certainly change the look of the glaze. Especially if you are using the copper bearing glazes, and it sounds like you are. Not only will the glaze change but you will lose the beautiful black color of the clay. Try some experimenting, you will likely discover some interesting results. Years ago I smoked fired some work that I had added gold to and they came out gorgeous. You can either pull the pieces directly from the luster kiln while still very hot (1100 to 1300 F), or reheat at a later time and reduce them in your reduction cans once again.
Good luck, your journey will offer you many new and exciting possibilities, be courageous, embrace them.
My name is Andrew Vickery. I'm a college student from Dallas, GA. I
have access to natural clay sources here and I wanted to ask you if you
could possibly send a diagram to me of any wood-burning kiln plans that
you may have. I would like to try and build a small one and I have never
found a detailed description. Either that or you could possibly tell me
of other online resources that are useful for this. I would really
appreciate it. Good work by the way!
Look in the
latest Ceramic monthly, June, July, and August 2002. On page 110 and 112
Nils answers some questions about wood fire kiln construction.