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Pres

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Everything posted by Pres

  1. Denice, I also recycle my clay. First because I live in the city, and would not know or want to dump clay anywhere. Second because I believe it is a resource, and try to use it. Happy to know someone out there has the patience for coil pottery, and uses colored clays to enhance it. best, Pres
  2. Since there was no recent QotW in the question pool, I will once again pose a question: What process do you use with the clay you use, including glazing and firing range? I have used several different clays over the last several decades, starting with a wide firing range clay that I fired to ^6, didn't work out too well as it never seemed to be mature. Then I went to a clay similar to the one I used in the HS, a ^5-6 clay that was quite nice, very throwable, good for handbuilding, and speckled, however mine did not speckle. This was so that I could not be accused of using school clay(watch your back). After I retired, I did use the speckled version, but stopped using it as I became concerned of the manganese in mortars, and I was getting a little bored with the clay. Next I started using a hazelnut brown and a white that both were ^5-6. I found the hazelnut great to throw with, but glazes turned out darker. Then started to glaze both with a white glaze before spraying on colored glazes over top. I find that this has allowed me to get the color to accent the textures I stamp/incise into the pot before shaping. It still seems to be a learning process as now I believe the white glazes underneath leaches color out of the sprays on top, last batch I use the white glaze only on the inside and down an inch of the white clay pieces . Added as an edit: Whooops, guess I do need to say that most of what I do is wheel thrown, with some going to slab construction with wheel thrown components. Most of the ware is functional, unless it gets big enough to be considered super functional. Stoneware clay is what I use, as I prefer the feel over the buttery feel of porcelain, but that too may change. The step in that direction would be to find a porcelain at ^6 that I can like. Asking one more time. .. . . . What process do you use with the clay you use, including glazing and firing range? best, Pres
  3. Started a firing last night, something told me no right. I turned it off and waited til it cooled but, not before I noticed top coil was not firing. Later found that the SC-20 fuse on the right side on top layer was blown! No replacements until this morning with a walk to Ace Hardware. Firing now

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    2. Denice

      Denice

      I am  glad you listen to your gut,  I get  gut feeling also.   I almost lost a lot of money not listening to my gut.   It was a big decorating job  of a well know local celebrity.   They had fired the decorator and wanted me to take over the job.  I didn't want to do it  but friends and relatives talked me into it.  Before I had any time or money invested in it they decided to give the last decorator another chance.  I was so relieved,  later in the year I found out that they didn't pay any of their subcontractors.  I could have lost $50,000 on a job like that.   I don't let anyone talk me in to something I have a bad gut feeling about anymore.    Happy birthday,  I will be 67 October 15.   Denice

    3. Pres

      Pres

      70 here folks, thanks for the best wishes!

       

      best,

      Pres

    4. Pres

      Pres

      8 pm, Kiln dropping ^5 right now, 

       

      best,

      Pres

  4. At least it was a good time to clean out the shop! best, Pres
  5. Is this the load you had? If this is the load, you really did not fire too long, as such a loosely packed kilns does not conduct enough heat to reach temperature. At the same time, I do not fire long at all on either low or medium, usually firing right after glazing with lid open part way and bottom two switches on low for an hour, then I close up the lid leaving the peeps out, turning switches to medium for an hour, close her up and switch to high on all switches. Usually fires 6-7 hrs to reach ^6. However, I always pack a full load as radiant heat transfer is the most efficient way of evenly heating an electric kiln, pots on the outside heat up the pots on the inside, when the kiln is half empty not radiant heat. Electric kilns do not have air currents to carry heat to all parts of the kiln. best, Pres
  6. It makes me wonder about so much that I used to take for granted when teaching. Think I have told the story here before about finding radioactive materials in our copper enamels back in the 70's. Wonder what amount of precaution was taken back then for mining, and refining these materials for packaging and use? Look back to the different things that later were found to be harmful. . . Fiesta ware??!! I think almost everyone had a set of that, or some pieces in the 60's, I know my parents had the green set. best, Pres
  7. Recently, Min posted by way of @preeta : @preeta brought something up that I've been pondering for years. In this thread she asks "i wonder are potters now going to treat cobalt blue like blood diamonds? Whole ‘nother Subject." I realize as potters there's a strong probability that the cobalt we use is from the DRC and child labour plus health and safety concerns is a very valid concern in the mining practices there. We are not the reason for the mining, battery market seems to be the big driver now, but how do we feel about using cobalt or for that matter do we look into the mining practices of any of the materials we use? Cadmium inclusion stains to my knowledge are only being made in China and India, now why is that? (rhetorical question) For myself, even though I have been aware of the problem, I believe that much of the fix may be as much a problem for potters as the cure is for the children. Conditions in 20% or more of the mining operations use child labor in horrendous circumstances. However, as the demand for cobalt becomes more and more prevalent for car batteries, and other smaller modern batteries, the demand will climb, as will the need for more efficient methods of mining. This will mean mechanization, and other cost saving measures that will probably remove children from the equation. That said, it is rather certain by all predictors that the cost of cobalt will go up, and the welfare of the children will be in further jeopardy with this source of income. I will continue to buy cobalt, hoping that my suppliers buy from the 80%, but at the same time I use very little cobalt carbonate in my glazes, and no cobalt oxide. Asking in another manner, How will you treat the use of cobalt in your work? best, Pres
  8. I would go with the JB weld, but if you have some gap issues in areas, the JB weld epoxy putty, or the gorilla epoxy putty would be very useful to bind and fill small gaps. Both of these can be painted to match the color of the sculpture. Years ago when teaching HS I used epoxy putties to repair decorative pieces that were accidentally broken, worked extremely well, and very difficult to find the break afterwards. best, Pres
  9. hmmm good solid base, would work to hold a thin layer of something like cement board, smooth surface. I have a concrete wedging table, 3" thick. It has a canvas cover, as it is a little uneven. I also have a plywood 1/2 surface that I cover the table with to wedge the white clay that I use. I can wedge fine on either surface. To me what you have is a good weighty base, cover it for a solid non wobbly surface for wedging. best, Pres
  10. birdypotter, Firing up and firing down is to fire to cone target using a your normal firing, and then using your kiln switches control the cool down of your kiln. Most newer kilns now have a controller that will allow them to fire up and fire down thus slowing the cooling process. If you only have sitter, you can raise the brace use a twisty tie to hold it in place, and then use one, two or three switches on low to fire down. . . slowing the cool down. This will often help with dunting if your kiln is cooling too quickly. Older kilns had a tendency to be thinner walls, and cooled faster. Most newer kilns are thicker. . .2 1/2 to 3", at the same time lid thickness matters, where I used to have two inch lid, when I replaced it, I bought a 2 1/2 inch lid. These are some of the ways I have overcome cooling dunts. If you have not read any of my earlier posts about firing, my kiln is completely manual. . . . no sitter, and no controller. All my firings are done by hand with careful changes of switches to keep a balanced firing. Cone tests indicate I am with in 1/2 cone temp from top to bottom on most firings. Most problems with clay bodies may be overcome, and you may need to call the manufacturer and querry the problems you are having and ask them for solutions. Their tech people should be able to help you out. best, Pres
  11. Cooling dunt to me also. Considering the effort you are putting into this, I would do a few things, fill the next load to full, try firing down (using the controller or switches), and make certain not to open kiln early. Much of the advice above is useful, and should be followed especially when considering the testing of COE, and your absorption. There have been several threads on this site stressing the problems with wide range clay bodies. I have had my own problems with a body that was meant to be the "do all". . . . it did nothing well! Because of that I would consider changing clays if you are not too invested in this clay body. I could understand hesitancy to change, as I have just purchased a ton, and would not want to change if I found I was having problems. I had some problems years ago with cooling dunts that you would not believe, bisque pieces that cracked in spirals, glazed pieces that had base cracks both vertically and horizontally. In the end, I changed up firing and down cooling so that it did not happen again. Experimentation can be expensive and frustrating, but in the end you learn a ton of stuff about kiln firing and temps. Remember also that a kiln that has fired can still be monitored by a color temp chart. This will help to approximate the cooling speed. Testing is probably your only way out. best, Pres
  12. 10 year warranted Brent. . . guess my 20 year old wheel is past this. . come to think of it, I haven't even replaced a belt yet on my CXC! best, Pres
  13. Even though denser, most porcelain jewelry can be thinner than earthenware. Areas where findings may go through holes and such can be stronger also in the porcelain. In the long run color will be brighter with porcelain also. IMHO best, Pres
  14. Yes, theory confirmed. Logic does say that as a cone measures "heat work" not temperature that using cones more than once is problematic or inaccurate. I have never reused cones as it only takes a tad of time to change up. However, most of my firings do not get interrupted, excepting for one in a thunderstorm where the transformer was hit! Any more, I am better than close with heat color, especially when doing bisque. Glaze wise, knowing heat color does prepare you for shut off time/timing. best, Pres
  15. Liam, I box bowls rim to rim, and put a mug inside for bisque loads, for glaze loads, yeah lots of space lost. However, their are times that I wax rims, or bottoms and then stack upside down right side up next to each other. Crazy I know, but some folks like the natural rim. best, Pres
  16. Chilly recently posted in the QotW pool: How far back/deep do you feel compelled to go in your pursuit of pottery (or insert another craft/art here)? As I am not what you would call a purist, I do not mix my own paints, or inks, but use limited palettes that are expanded greatly by my skill of mixing color, when using watercolor or acrylics. As an art teacher, it was what I used, and knew. As an art teacher also, over the years I became pretty acquainted with ceramics, and became most inclined to continue work with it. However, I have never been interested in pursuing the digging of my own clay, let alone the refinement of it. In the long run, I do what I did lately, bought clay! As far as glazes, I started out using studio glazes from my college classes. We were given a Nelson text to purchase, read, understand, but at no point in undergrad did we actually mix glazes. When starting to teach ceramics, as the teacher before me had used commercial glazes, I continued. However, he used ^06 clays and glazes, which I did not like to work with. He also used the crappiest of the Amaco white clays on hand. Yuch! When I started teaching all of the Ceramics classes as he was too busy with the other classes he taught, I moved everything to ^6. I started with powdered glazes, large lots, then as I became more secure, following grad classes, started mixing some from books, then started modifying these, and moved slowly into mixing all of the studio glazes. I really am not interested in mixing my own clays, as I really don't have the room for this type of studio, and I am also content with what I am and do. best, Pres
  17. My CXC was purchased new in 89 I think. Foot pedal has been changed some for quieter running. It had the 1hp motor, and same belt drive as there is today I do believe. best, Pres
  18. If I remember correctly, Marsha S. uses little coils under large flat pieces also. best, Pres
  19. Preeta, years ago, I was throwing some large platters, and they wanted nicely finished foot rings with a shallow curve to the form. This was not possible with out a lot of trimming. so I threw them upside down, on this bat, made the double foot ring with large enough outer ring to support the curve at out edge, then the inner foot ring to support the center. Worked very well. Sometimes the obvious solution to a problem is not the best one. For a bird bath that was not flat, but evenly round, and with a foot ring to fit the pedestal base, this was the only solution I could believe most efficient, especially since I had the plaster domed bat. best. Pres
  20. When attaching handles, I wait until pots are cheese to leather hard trimming usually 20 per batch. cover with plastic. Then wedge up clay for extruded handles, load extruder, and extrude first tube. I attach each handle with magic water, as I believe fits the pot, back fill the bottoms and finish curve of handle using regular water on a finger wiping the inside curve only. Set the pots aside on fresh ware board, and allow to dry. No covering, nothing no cracks. best, Pres
  21. Doc I just fired a bird bath top for a friend that let his freeze. I made mine by throwing upside down on a plaster domed bat with a 2 1/2" rise. Centered ball on top, flattened down around the edges. the center flange to hold the top on the base was thrown into the bottom from same piece, after drying to leather hard, added a thrown ring to top to deepen water area. This 22" platter was fired upside down in bisque, and upside down in glaze firing, leaving the rim unglazed. I was afraid it would collapse around the collar with such a cantilever. Thrown to glaze fire time was 1 1/2 weeks! Buddy was very pleased with the replacement. I believe as others that it is your glaze firing expansion/contraction causing the problem, not your making skills! best, Pres
  22. If your wheel is reversible, take a second or two to recenter, and using the wheel in reverse use a rounded wooden spoon or other tool to smooth/burnish. best, Pres
  23. I use dremels a lot, sometimes on a rough spot on a glaze piece. . . use a rounded point grinder, then finish with a rubber polishing bit. Not often, but when needed really works well. I also use the them in the studio to carve wooden stamps, and smooth some bisqueware, and also to remove the smallest areas of glaze spots on shelves. I used to carry a battery rechargeable one to shows to smooth edges of pieces if I felt a roughness I did not like on the base. bst, Pres
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