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Dick White

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Everything posted by Dick White

  1. You say "Wire is ok." Are you specifically saying you have a 40 amp (8ga wire) 240V circuit in that bathroom?
  2. None of them "calibrate" themselves. There are too many variables in the kilns and associated hardware to create a perfect PhD (push here, dummy) solution at the manufacturer's level, though most of the kiln purveyors would like you to think their kiln always produces perfect results and many potter-customers unknowingly think they are getting what they are supposed to be getting. The only accurate measure for firing is proper witness cones around in the kiln. The cone-fire schedules in the controllers are preprogrammed to the exact specifications of the Orton cone table, but variances in kiln heating capabilities due to wear, loading, or other external factors, and possible thermocouple inaccuracies may cause a different outcome. One should fire the automatic schedule with witness cones inside and compare the bent cone to the controller expectation. From there, you can tweak temperature offsets into the controller to shift the outcome back to where it should be.
  3. @Bill Kielbis usually more right than me about so many things, but this time he is half wrong. The Genesis and the Dynatrol (and the V6-CF) are all the same physical size with the corner mounting holes in the same places. (Skutt is the only one who has to be different with a larger faceplate that the underlying Bartlett it is derived from.) The connections on the back of the Genesis board are the same size connector blades and functionality, but are in slightly different places around the edge, so review the wiring diagram in the back of the manual to put the wires on correctly. Otherwise it is plug and play. Been there, done that. If you get the Genesis, also get the optional current sensor so that it can monitor actual electrical usage and calculate firing costs based on your utility rate. Even if the shop doesn't have one of those in stock, order it for later installation, which is easy. Edit to add - once the wifi is set up in the Genesis, software updates are handled by download from Bartlett. They are not Windoze-automatic in the middle of the night, you have to scroll down through the menu and do it purposefully. If you understand the logic behind the long-standing operation of the earlier controllers, it is all the same here, just more robust and easier to see what you are doing on the touchscreen.
  4. That one is 240v (220 isn't much of a thing anymore, the national grid is standard on 120/240 now) and being small, it should be able to handle midfire with no problems. The issue with small kilns and testing is that they cool so much more rapidly than a big kiln, so your glaze results may be different. To get around that, you need to be facile with the ramp hold programming so you can add slow cool segments to the end of the firing. As for the pilot light, that's just the little red light bulb on the side of the controller case that blinks on and off in tandem with when the elements are on.
  5. Does anybody know the secret code of keypresses that will allow one to access the deep dark secret diagnostic and configuration menu? This one is from before there was a Menu button on the front panel. Thanks dw
  6. @BeebopFor this gray Amtalc C-98 talc, definitely go big now while you can still get it. You might not be able to get it in another month or so. Then you will have enough to settle in on. The other materials will likely continue to be reasonably available, so a smaller quantity will not leave you in the lurch.
  7. Also be aware that the Texas Amtalc C98 (which at one time was branded as Pioneer, same stuff different name) is going off the market at variable rates depending on the depth of the inventory at the distributor that services your local supplier. The Amtalc mine was bought by DalTile a few years ago, and a few months ago they decided to stop selling it outside of their own production needs. As soon as you figure out how that 5 lbs works, you'll have to deal with talc from a different source. The joy of potting.
  8. Yes, most sparkies are responsible within their area of expertise and don't immediately recognize how different a kiln is from just a big hair dryer in the bathroom. And not being familiar with the Skutt et al websites where explicit specification are listed, they would look at the rating plate and do what seems normal for the numbers on the plate. It's the few who show up in a pottery group and insist that because they have a license they know what they are talking about and and it absolutely must be fused at the rating plate. As noted, most sparkies are responsible and will adjust their opinion (and work) when the strange nuance of 125% is shown to them, but every once in a while we get into arguments about it. I don't have a license, but I can read the code and from that understand why Skutt et al say what they say. Thanks for everybody's help and input,
  9. Thanks folks for all your input. The thing that is driving this question is a bit of a tif going on over in another pottery group. Somebody bought a new kiln and their regular household electrician refused to put a 60 amp breaker and wire on a 6-50 receptacle, insisted it had to be a 60 amp outlet or a 50 amp breaker. Another self-described "master electrician and hobby potter" opined that 50 amps is all that is needed. His defense against the continuous load requirement is that he has heard the relays in his kiln clicking so that makes it not a continuous load. As if the short pause, if any when coming into mid-fire or high-fire maturity, is enough for the cable to cool off... And what about manual kilns that are simply full on high for the last 6 or more hours of the firing? And the rest of it is just good common sense - listen to the kiln manufacturer and don't use the breaker as a convenient on-off switch. Anyway, on to the next battle.
  10. Another silly question for the deep dive experts. We often toss about the 125% rule for wiring kilns, e.g., a 48 amp kiln needs a 60 amp circuit. Reading around in the code book to find the exact passage that requires that, I see in 210.9(A)(1)(a) that the wiring of a branch circuit containing a continuous draw must be wired at 125% of the continuous load in accordance with a wire table later in the book. Does this require that only the wire be 60A-capable (6ga plus whatever for voltage drop due to length), or does this 125% include the breaker too, or would a 50A breaker and 6ga wire be acceptable? Thanks.
  11. I tried the sausage mixer. Nice idea, but didn't work very well. The clay sticks to the blades and the whole thing turns as one, no mixing occurs until you wet it down to slip slop consistency. And then, once mixed, you have to dig it out with a spoon. If you lived near me (or I had enough money for a vacation in France) I would give it to you.
  12. Oh my, you have a small problem there. As Pres notes, it is indeed a 120V kiln. It is rated to draw 16 amps, which requires a 20 amp circuit. The plug in your picture, however, has been improperly "altered." A 120V/20A circuit uses a NEMA 5-20 plug and receptacle in which the flat blades are not parallel. Your picture shows that the blade on the left side, which was supposed to be vertical, has been twisted to horizontal to match the blade on the right side. This changes it to a NEMA 6-15 configuration, which would be 240V and 15 amps if the matching receptacle is appropriately wired. Thus, if you are driving the originally specified 7.5 ohm elements at 240 volts, the kiln will be drawing 32 amps or twice the rated amount for the plug/ receptacle/ circuit wiring (and probably the kiln internal wiring too), and the kiln will be running at 4 times the designed wattage. If you change the circuit and its receptacle back to the originally specified 120V/20A (i.e., NEMA 5-20), you will need to cut that altered plug off and repair it with a proper 5-20P plug. Do not just rewire the existing incorrect receptacle and put a different breaker on the circuit. Plugs and receptacles have specific configurations of prongs and slots for each different combination of voltage/amperage, so if someone in the future sees a what appears to be a 6-15 receptacle on the wall with both slots horizontal, they should expect the voltage from it to be 240V and up to 15A of available current. Consequently, their device that has a matching plug would fail because the outlet is not providing the correct power. Always be sure plugs, receptacles, wires, and overcurrent protection (the breaker) properly match industry standards so that everything will work safely and correctly now for you and for a future user of that outlet. As for new elements, Euclids.com can provide elements for just about any kiln ever made.
  13. Pics are not accessible - you need to set them to public on your google drive or transfer them here.
  14. You can buy a whole new power cord from Skutt for $98.00, or just the plug end for $58.00. In electrician-speak, the plug is a 6-50P (that's the NEMA designation for that configuration) and the receptacle is 6-50R. The receptacle will probably be easy for the electrician to find, but the plug end may be more difficult to find locally.
  15. I too use a woodworking miter box and a wire in an old hand jig saw. I have a piece of thin foam across the bottom so that the wire can push into the foam so as to cut cleanly all the way through the extrusion.
  16. Thanks @Bill KielbMy thoughts about the S-type TC derive from the conventional wisdom that K-types have uncertain (but probably not huge) inaccuracy above 2000F, and will drift over time as they wear. I don't know if K-types are slightly variable at manufacture or if a new TC were properly dialed in for cone 6 with the controller, one could put a different new one in every day and each one would be spot on every time? Certainly, it would seem that replacing an old one where the controller has been recalibrated from time to time to compensate for age-drift would require the offset to be tweaked back. But, conventional wisdom purports that the S-type suffers neither inaccuracy at mid- and high-fire temps nor drift. Just sudden failure at EOL. As I am upgrading my kiln and would like to get back into some crystalline glazes that require a fair degree of temperature accuracy, I'm trying to decide if the S- route is worthwhile.
  17. When installing a new K-type thermocouple (or buying a new kiln with a K), there is some calibration of the controller required to adjust the offset so that a witness cone bends at the stated temperature per both the Orton chart and the display on the controller. I am considering a switch to S for greater accuracy and am wondering if these typically are accurate out of the box, or will I need to run several firings to tweak the controller offset until everything matches? Thanks
  18. Having dabbled in crystalline glazes more than a few times, my understanding of the process is there is way way way too much zinc (25%+/-) in the recipe for a "normal" glaze, but it is all incorporated into the melt at peak temperature in what might be similar to a supersaturated solution. There is very little calcium or alumina so that the molten glaze is nice and loose (runs like the dickens) for the crystals to grow without any impediments. While the silica molar level is low in absolute terms, with almost no alumina, the Si:Al ratio is over the moon. As it slowly cools, the zinc molecules precipitate out and readily find the excess silica molecules to form and grow the big zinc orthosilicate crystals during the multi-hour hold at temperature. I will try to put in a picture from EU-Cal of one of my recipes. The excess silica is 7.55 and excess zinc is 3.44. That stuff has to go somewhere, so it forms crystals. The crystals also absorb colorants that are in the recipe, but in a standard order of electron valence, leaving some of them in the background. I have not tried a reduction firing, but those crystalliers who have report it's a hot mess if reduced on the way up, but if there are reduceable colorants in play, they will do all sorts of pretty things on the way down after the crystals have formed. (@BobMagnusonAwesome tool, btw. I will be sending you a request message later.) EuCal_ver1_9dw.pdf
  19. Anthracite is coal, which is carbon. It will burn out during the firing.
  20. Well, actually, there is a problem that is specific to the Shimpo Whisper, Giffin has acknowledged it and is trying to develop a solution. I don't know the progress on that. The physics principle involved is that when you accelerate the wheelhead, the differential momentum of the accelerating wheelhead (which the lower part of the Grip is attached to by the friction of the legs) vs. upper plate of the Grip which is still stationary or rotating at a slower speed will cause the pads to move slightly inward on their spiral tracks to maintain the grip on your piece. With the direct drive electronically controlled motor of the Shimpo Whisper, when you take your foot off the pedal to stop, it stops so fast that the differential momentum between the top and bottom plates of the Grip reverses, the top plate keeps spinning slightly after the wheelhead stops, and the pads are moved slightly outward on their spiral tracks. Every other brand of wheel comes to a stop slowly enough that the friction between the top and bottom plates of the Grip keeps everything in place. @AlexX If your wheel turns counterclockwise for throwing, etc. , then the top plate of the Grip should rotate clockwise when the wheel is stopped to tighten the pads. Hold a finger against the side of the wheelhead to be certain it doesn't move, and turn the top plate of the Grip each way to see which direction causes the pads to move in and which direction causes them to move out. If they move inward with a clockwise turn, then you have the counterclockwise model. If they move inward with a counterclockwise turn, then you have the clockwise model. Yeah, that's a head spinner in more ways than one... The upper and lower plates of the Grip need to be rotating in opposite directions with respect to each other to tighten.
  21. While waiting for your pictures, a kiln must be on a circuit that is 125% of the amperage of the kiln. Yours is 24 amps, so a 30 amp circuit is needed. The 8 ga. wire is more than enough. Leave it alone. Your kiln had a 50 amp plug. This is probably just a convenient coincidence, as that is what larger kilns use, so perhaps they just built them all with the same power cord, less inventory to keep on hand in the factory. It doesn't need to be 50, but that's what was there. You've already cut it off, so you are stuck with that. It would have been easier to change the outlet on the wall for one that fits the plug, but you are where you are so put the plug on the power cord. Your picture of the circuit breaker for the kiln is cut off, can't see the numbers on it. Note that on 240V double pole breakers, the number on the handle is for each side of the circuit, but they do not add together, i.e, if the numbers are both 30, it is 30, not 30+30=60. However, If it is truly a 60A breaker (both numbers are 60), that is dangerous. The kiln only needs 30, the 8 ga. wire is only good for 40, but the breaker won't blow until a 60A error occurs, at which time the kiln will already be fried and the wiring on fire (that's a bit of an exaggeration, but don't have a larger breaker than the wire can handle or significantly larger than the kiln draws even if the wire is ok at the higher amperage). However, it is ok to have a smaller breaker than the wire size, just not the other way. So, change that breaker to a 30A and your kiln will be good to go.
  22. Ha. For some, this glaze chem stuff IS wilderness camping. All. The. Time.
  23. Dip the tip of the syringe in the glaze and then tare (zero) the scale to adjust out the weight of the empty syringe plus the little bit that will be on the outside of the syringe tip. Snarf up the 100ml, and weigh it straight. The number on the scale IS the S.G. No need to mentally subtract out the syringe itself.
  24. This is an interesting and useful discussion. I too have noticed the top and bottom sections "working" harder than the middle, but didn't put it together the way you just did. I wonder if this is where Skutt gets it by putting hotter elements at top and bottom? If one paid extra for a Skutt with 3-zone control and the touchscreen, would the data dump show the top and bottom sections at lower percentages, closer to the middle section to maintain even temperature?
  25. People who have a Skutt 181 seem to like them, though that model is long out of production. It will be a manual kiln with switches and a kiln sitter. While new kilns with a digital controller often have a price premium of ~$200 over the comparable manual model, the cost to add a standalone digital controller to a manual kiln is in the order of $6-800 depending on the features. $600 for this small one is a tad high but could be worth it if it includes shelves and posts.
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