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Dick White

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Everything posted by Dick White

  1. As I noted in this thread back in Dec, Terry is The Man Behind The Fallonator. Plumbing of the highest order meets pottery of the highest order! dw
  2. What Mark C. said. The caps are black rubber, and form an integral part of sealing the chamber when vacuum de-airing the clay before pugging it out. It has been my experience with both our Peter Puggers that if the inside of the rubber cap is not kept clean, it will not properly seal and a vacuum cannot be achieved. Thus, regarding an earlier suggestion of putting a piece of plastic over the end of the barrel before putting the rubber cap on over it, that may or may not produce an adequate seal for the vacuum process. Try it, YMMV. And yes, both our PPs leave a blue-green-grey stain in the center of the exposed end of the last pug left in the barrel when the machine is empty. In my experience with both dark and white stoneware, the stain does not affect any of the fired wares. Again, YMMV.
  3. Magnesium oxide is a flux that helps a glaze melt and imparts certain characteristics to the glaze surface. It is not generally regarded as toxic, and is found in many over the counter pharmaceuticals. It is not a colorant. Are you asking about manganese dioxide?
  4. Uneven stress between inner and outer glazes will cause this. It doesn't matter if the uneven stress is inside to outside, or outside to inside. Keep your single inner layer of Licorice but go easy on the multiple thick layers on the outside. If you must layer the glazes on the outside of your mugs, do it with thinner coats so that the total glaze thickness approximates the single layer inside.
  5. The issue of "distance" from the panel is one of voltage drop. In order to deliver the necessary amperage and voltage to the target device, the wire needs to be the proper thickness. More amps requires thicker wire. That's standard stuff, kiln manufacturers list the requirements in their specifications. But excessive length of the wire may cause a decrease in the voltage. 50 feet is about as long as you can go without incurring some voltage drop. However, this can be remedied simply by increasing the thickness of the wire. When your electrician installs the wiring, ask him or her to calculate the voltage drop and upsize the cable as needed.
  6. The video in the URL starts with a still photo of a lidded box with a black and white top and red chattered sides. I didn't see the vase. The top of the box lid was a slab, textured with a roller, shaped, and then applied to the top of the open thrown cylinder. The glaze on the top of the lid looks to me like a temoku type of dark transparent glaze that breaks clear over the edges of texture,
  7. I have found with my homemade sig that the surface of the bisqued ware is so tight that studio-mixed dipping glazes aren't absorbed properly and the glaze is too thin. Perhaps commercial brushing glazes will adhere better?
  8. For the USA crowd - regarding blenders, the blending pitcher that screws onto the blade base of Oster and Hamilton Beach blenders has the same thread size as a standard "mason" canning jar. Measure your materials into the jar, screw the blade base on, flip it over onto the motor, and whir it until done. Then put a lid on it. I can make a 400g sample in a quart canning jar.The Waring brand blender has a different thread for its pitcher, so doesn't work this way.
  9. Elaine, LT-4 (and LT-3) is not a brand of kiln. It is the model number of the Dawson Kiln Sitter safety shutoff control on the kiln. Most manual kilns of any brand use that same device. The brand and model of your kiln should be marked on the electrical rating plate, a small metal label usually attached to the side of the switch box on the kiln.
  10. The following is a mixture of facts, speculation, and invention off the top of my head. Some months ago there was a hew and cry in several pottery-related Facebook groups about an impending demise of the availability of spodumene. Everybody was rushing to buy the last available material from their usual sources and there was much rending of clothes that they would not be able to make their favorite glazes anymore. I never saw any rigorous business analysis of the issue (other than the obvious market impact on the price of lithium caused by the huge demand of the lithium ion battery industry) to explain a cessation of availability of spod. Some US-based commenters pointed to their favorite suppliers having warehouses full of the stuff. The only logical comment I saw in all the discussion was from an EU-based person who indicated there was some EU regulation that forbade dividing branded merchandise into smaller quantities and reselling it in unauthorized packaging. The company mining spodumene in western Australia (generally referred to as Gwalia Spodumene) supposedly ships its product to distributors worldwide only in very large ~200 pound sacks, and distributors would rebag it as needed for local resale. It was this end-of-supply-line issue that ran afoul of the EU regulations. There hasn't been much noise recently about "what should we do now that spod is gone" as there was at the turn of the century was when the gerstley borate mine closed, so perhaps it was much ado about nothing, a false alarm. Or perhaps the ingenuity of the potters in affected areas developed a workaround - source the spod (and lithium carb) in the standard big bags from the original producer and reblend it with an immaterial amount of something innocuous into your own proprietary product and sell it in whatever quantities you wish in your own bag?
  11. Another cause of the E2 code is a relay stuck in the on position.
  12. Some years ago our school studio upgraded to new 3" brick kilns but kept the shelves from the old 2.5" brick kilns. We use only half shelves so we were able to make it work by allowing the inside straight edge of the shelf to slightly overlap the centerline and load so that the half shelves never were at the same level. Your specific situation may be different.
  13. A canvas-covered table would not be compatible with the big Bailey slab rollers. These slab roller compress the clay by drawing it through the pair of rollers and sliding the thinned slab across the outfeed table. The tables need to be shiny and smooth so that the clay (which is sandwiched between canvas sheets or a slab mat) can slide with no resistance. A canvas-covered table would have too much friction against the sliding slab.
  14. They look like test tiles cut from extrusions. The hole allows you to hang it on a hook on a wall display.
  15. One thing I will add to the discussion about flocculating and deflocculating a slip (or glaze) is the chemical reactions are reversible. If you mistakenly over-flocculate, you can just add some deflocculant to thin it out again, and vice versa. In your case of wanting a thickened decorative slip, the issue is complicated by shrinkage on drying. A slip that has been flocculated to thicken it so it stands up on the surface of the vessel still has the same clay-to-water balance, and will shrink and crack as it dries. It is better to create a slip that has more clay in the same amount of water. The problem is that you can't put enough clay into the same amount of plain water to accomplish this as it becomes too thick as mud to stir. You then deflocculate the slip and it instantly turns runny, and now you can add more dry clay. You must add dry clay, not more slip. You are trying to raise the amount of clay in the existing water, and adding more slip adds more water at the same time as it adds clay. So, as Callie suggests, take some dried greenware made from that same clay, crush it to powder (inside a doubled plastic bag to control the dust) and add it to the developing slip until it finally is the thickness you want. Be sure to sieve it to get all the lumps out.
  16. This is not responsive to your question in the second paragraph, but about the causal issue you refer to in the first paragraph. If you put some green or blue food coloring in the wax resist, you will be able to see exactly where it has been applied. Don't use other colors as they are hard to see against some clay bodies.
  17. Check your connections and the continuity of all elements. It is possible for a kiln to reach the 1700℉ range with one element out. But it won't go much past that. Perhaps the connector to one of the elements has come loose or there is some damage to one element. For a quick test of whether all elements are coming on, slip a scrap of paper behind every element, then turn it on to some program, doesn't matter what program, for 5 minutes. Then turn it off and check the paper scraps. Any that are charred are behind working elements, any that are not charred that element did not turn on. Troubleshoot from there.
  18. If your floor sags and wobbles when you walk around on it, then the wheel will wobble when someone else walks by. If your floor is steady when you walk, then the wheel will be fine too. The motor of some wheels has a bit of hum when it runs, and the wood floor may act like a sounding board and the noise will be louder than if on a non-resonant surface.
  19. As a glaze chem instructor, recipe formatting is a dicey subject. Each roll of the dice produces a different answer, depending on who you are, where you came from, and why you are here. So let's cover the basics. The total quantity of materials in a base recipe should always total to 100 or very near to it. That 100 then can be interpreted as 100 percent, or 100 grams, or 100 ounces, pounds, or tons. Each individual material in the recipe will be measured in the same unit of measure, except for percentages as percent is not a discrete unit of quantity. But that's where the notion of 100% becomes useful. No matter what size gross batch you wish to mix, an item that is 27.2% of the 100% total base will always be 27.2% of the gross batch. Now it is just arithmetic to make a small batch, a larger bucketful, or a barrel, and the proportions will always be correct. There are 2 schools of thought on the 100% rule. Some believe the entire recipe, including the colorant oxides, opacifiers, suspension agents, etc. should total 100. After all, it's 100% of the whole recipe, right? Others, including me, believe the 100% should apply only to the fundamental materials (fluxes and glass formers) while the colorants, etc. are additions above the base 100%. This allows one to change the color of a glaze without changing the underlying glass, or easily analyze or compare the content of a several base glazes without needing to recalculate them to a common denominator. Next, you have batch sizes. Many potters consistently mix each of their palette of glazes in a particular batch size based on their studio's needs. Some batches are large, others small. A potter's notebook may show a glaze that is a mainstay of the studio as having a list of materials totaling 8,743 grams while another recipe totals only 954 grams. There are no calculations to be made, just weigh out what the list says. That's what works for that potter's routine, but may not be useful for others. Finally, we must address the presentation order of the materials. Classical methods of using glaze chemistry to construct a glaze recipe typically start with the most complex of the raw materials, usually the feldspars or frits. These bring in the necessary fluxes and the quantities are manipulated to create the desired balance of fluxes. Single-oxide flux materials are also added at this time. Next, the clay materials are added to bring alumina up to the desired level, and finally pure silica is added until the recipe is fully balanced. Listing a recipe in this order demonstrates an intellectually rigorous development of the glaze, and many old-school potters keep doing it that way because that was what they were taught was the proper way to do things. However, that makes mixing the glaze more difficult than it needs to be. Some find it easier to stir the various materials into the water if they are added in order from largest amount to smallest, stirring the bucket after each addition. I find it best to always add the clay materials first so that the beginning slurry is immediately flocculated, and thus subsequent materials do not quickly sink to the bottom and hardpan. Then the rest of the materials in size order, largest amounts first. Thus, my preferred format is probably different than any you might find in other potter's notebooks. You have Mr. Beardsley's books in whatever format he kept them, so you have a choice - you can simply republish them as found (and we must sort it all out), or you can do the recalculations and reformatting to suit some other standard.
  20. I am not familiar with exactly what Skutt might have done to change the standard Bartlett Genesis programming in their version of it, but the stock Genesis has a checkbox to turn "Slow cool" on or off at the end of a standard cone fire. When enabled, it does a 9999 drop to 1900F and then 150F/hr to 1500F. This may not be exactly what is in M^6G, but it is close enough. Check if your Skutt device has that same checkbox.
  21. It is common that DC motors are harder to spin one way vs. the other, the Shimpo Whispers are the only ones I'm familiar with that are totally free spinning when not on. It sounds like you'll need to do some electrical diagnosis to determine if there is a controller fault or cable fault and there is no power reaching the motor, or if there is power reaching the motor, then the motor is faulty.
  22. Could you get a science department lab coat and modify the lower part of the back so that when you leave the bottom several buttons open, the long coat functions like a split leg apron but now with sleeves?
  23. Can you loosen the belt tension (and possibly take the belt partially off) so that the motor can run free? What happens now? Does the motor spin up (and change speed with the pedal)? If the motor spins up with no tension on it, then the problem is later in the drive train. If the motor hums but doesn't spin up (even with a little twist to get it started), then it's a motor problem. If the motor doesn't even hum a bit, its a controller problem.
  24. Not trying to defend the kiln manufacturers, but if they felt obliged to put 60A plugs on their power cords (which in turn would oblige us to put a 14-60 receptacle on the wall), now we are all at 4 wire configurations. Given the basic price of a kiln (and for the user, the price of the installation), another wire shouldn't be a deal killer. But then I don't own a kiln company. I just fix them.
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