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Dick White

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  1. I thought about the same, but who am I to challenge anybody at Skutt?
  2. Someone just told me that Skutt told them that after installing a new thermocouple, the kiln should be prefired empty in the same manner as for new elements. I never heard of that before, but then there are a lot of things I've not heard of. Does this sound right to those of you who clearly know more than me? Thx, dw
  3. Yes, the problems are likely easy fixes, if only the bossman would tell the studio kiln loaders to stop using it long enough to fix it. But that's a different problem that needs a different fix.
  4. Since Neil mentioned it, I have recently been troubleshooting some issues with 2 of the kilns in our coop studio. To illustrate the problems, I downloaded log files from the Genesis controllers and analyzed them in Excel and graphed them in Powerpoint. The Powerpoint pictures (now in pdf format) are attached as examples for all to see both the kinds of things that can be extracted from the Genesis and the kinds of problems that the log files might reveal. The first picture, K1.pdf, is from a kiln that, in the view of the studio president, is operating nicely. Well, sorta. It gets to temperature and the glazes seem to come out well. But when you plot the actual temperature ramps vs. the programmed expectations, a different story comes out. During segment 3, programmed for an aggressive 300℉/hour from 250-1000℉, the kiln could only average about 265℉/hour, and consequently added about 45 minutes to the programmed expectation. Segment 4 was a sedate short waltz through silica inversion, but in segment 5 the kiln could not maintain the more moderate ramp rate through the entire segment, and so added another 30 minutes to the firing. Finally, in the slower yet ramp of segment 6 reaching maturity, the kiln lagged another 35 minutes behind the programmed ramp. So, the somewhat worn elements, while not yet causing an E1 and appearing to produce good results, is actually running 1 ¾ hours longer than expected. Neil also mentioned that the percentages shown on the screen present the duty cycles of the relays. I've graphed those in the brown line, so you can see how the controller is managing them as the heating requirements of the temperature ramps progress through the firing. (The differences between the 3 relays were reasonably normal, as described by Neil, so this line just averages them together.) The kiln in the second picture, K2.pdf is a hot mess. The firings were dragging on and on, but bossman couldn't figure out why. The graph of the log file shows exactly what was happening (but not why, I am still diagnosing it if only he'd stop using the kiln). For whatever reason, the bottom section (which has resistance readings reasonably consistent with the upper sections) is lagging 15-20℉ behind despite that relay going into overdrive at an early stage of the firing to keep that section on nearly 100% for the rest of the firing. And it still doesn't throw an E1, but don't let that fool you. Carry on. K1.pdf K2.pdf
  5. Something else to consider here (not saying don't do it, just that there is one other nuance). We had a discussion awhile back about these Sentry controllers that are programmed at the factory for a maximum temperature consistent with the design of the kiln it is installed on. If this one is on a low-fire kiln, the programmed maximum temperature the controller will allow surely is below cone 6. After rebuilding the kiln to have the full 48 amps of heat in a smaller volume, the controller will need to be tweaked to allow it. I don't remember how that was done, just that it took awhile before somebody found the steps for reprogramming the maximum temperature.
  6. A 14-30 plug/receptacle is really just two adjacent, but independent, 120V circuits from the panel so that they are on different phases of the incoming service. That way, certain positions of the switch can draw from both circuits simultaneously to get 240V. Other positions of the switch are drawing only 120V for which the neutral is required. That's why there are four prongs on that plug - two 120V hots, the neutral, and the safety ground. A 6-50 plug/receptacle is a full 240V circuit always drawing from both sides of the panel, and there is no neutral, thus only 3 prongs are needed on the plug. They cannot be mixed as one needs the neutral and the other doesn't have a neutral. You need to study the wiring diagram of the old kiln to determine how it uses and combines the voltages. Some old kilns were simply separate 120V kilns stacked on top of each other to create a similar amount of heat as a 240V kiln. Other old manual kilns with High/Med/Low switches used 120V on low and 240V on med. and high. Both these configurations require the neutral. Newer 240V kilns use only the two hot legs throughout the whole kiln. If you don't have a manual with the wiring diagram for your old kiln, tell us the brand and model and we can probably find a wiring diagram. The above does not address the amperage issues. As already noted by others, running a 45 or 48 amp kiln on a 30 amp circuit is an open invitation for the fire department to pay a visit. Get the circuit fixed first with a 60 amp breaker and wire size to match (this is needed to accommodate the 125% requirement in the code for kilns). Then we can sort out the plugs. If it turns out the old kiln is in fact a 120/240V device needing a 14-50 plug and receptacle with neutral, it is possible to put a 14-50 plug on the new kiln cord and just not use the neutral prong. That way you can use the same receptacle for either kiln. Or, maybe, the 14-30 receptacle is left over from an old dryer circuit, but you need to replace that whole circuit anyway before you can use it for a kiln. And because the older kiln draws 48 amps, the 14-30 plug on it is wrong right from the get-go. Or possibly the older kiln is a true 240V kiln and should have a 6-50 plug, same as the new kiln, but you need to replace that plug anyway. The kiln wiring diagram will inform us what is needed. As for why the top coils in the old kiln did not heat, that sounds like a wiring fault that needs to be traced. Again, the specific wiring diagram for that kiln is needed. So, to summarize, tell us the exact brand and model of the kilns and we can help you find the wiring diagrams. Then you can work with the electrician to get it all working.
  7. The energy regulator is also known as a simmerstat, as you've noted, but also called an infinite switch (because there are an infinite number of heating rates depending on where you point the knob, compared to other switches that are on-off or low-medium-high). It is a common switch type in kilns, so you might be able to use one from a different brand of kiln. Also, this type of switch is commonly used in kitchen electric stoves. Perhaps an appliance repair shop has something comparable.
  8. Is the energy regulator failed or just the gnarly connection? It might be that the cover of the regulator looks ugly but it works inside. Try pulling that connection apart, clean up the tab on the regulator, and cut the connecting wire back to good wire and put a new connector on the wire. You will need to fix that wire no matter if you get a new regulator or not. But that may be enough to get it working again.
  9. Fine with me too. It's an interesting additional level of glaze chem. Thanks Bob for originating it.
  10. Cobalt does that in some glazes. I don't know why, just that it is a common problem.
  11. The only way to know is to test it on you clay body. Some glaze recipes are quite robust and work over a wide range, and others are finicky within a narrow range. Even ones that are represented by the seller as having a wide range may respond differently on different clay bodies, both as to color and fit (shrinkage) over the range of temperatures.
  12. Chrome-tin glazes are opaque enough without the titanium. They also need a high level of calcium. Take out the titanium and put back the calcium carbonate, but only for the chrome-tin glaze. For the blue one, 4.5% cobalt is a lot for a glaze to keep in against acid and alkali attack. Take one of your blue pieces and set in sideways in a bowl of vinegar so that only half of it is in the vinegar. Leave it there for a few days and then wash it and let it dry completely. If the side that was in vinegar is still the same gloss and color as the other side that was not in vinegar, it is probably ok for use with food. If the side in vinegar is faded, the glaze was attacked by the acid and the cobalt leached out. That's not good for food use. Try some tests with less cobalt (2% or less) and decide if you like the color.
  13. My bad, yes, I used the the wrong sample, the 5g item. Your math is correct, so if it's 2.5g of sugar per 100g of wolly, that hypothetical bucket of glaze would need 3/8 cup of sugar to sweeten it. Even that seems like a lot sugar to put in the bucket. Now that the idea is out, I can do some "line blends" as I mix new batches for the students...
  14. So, from your experiment, it sounds like an addition of table sugar in the amount of 25% the weight of the wollastonite in the recipe will "solve" the clumping? For example, a recipe containing 10% wolly in a 5kg batch has 500g of clumpy wolly. Adding 125g of sugar (about 3/4 cup, one tablespoon weighing 12.5g per Mme Googlefu) will make that recipe fly through the sieve?
  15. I have not tried this, but is this something that could be addressed by calcining it? I use zinc oxide and certain frits that are hydroscopic, causing them to chunk up in the bag/bin. I calcine them to around 900F to remove the moisture but not so hot that they begin to sinter. Then I spin them through a coffee grinder to reduce the chunks back to powder. Just an idea...
  16. I think it is a mistaken typo during the input process, as Min suggests. If you look it up on Glazy, it is labeled as part of the Iron search. If it matters, she is part of the Facebook group on ceramic recipes, and I could reach out to her there to confirm.
  17. Just a sorta-humorous note along these lines... We had been talking about this, and though the college studio where I am a studio monkey was closed because of the pandemic, I suggested to the professor that she should order some to get us through the however long the shortage might be. We reopened yesterday for modified in-person studio work, and there on a cart were 4 bags of it, enough to last us the rest of millenium.
  18. Gare Kilns were taken over by Evenheat. User manuals for the old Gare kilns aren't among those published on the Evenheat website, but if you call them, they are helpful and can get the old manuals out of their archives for you. As for the capabilities of the kiln, some of that should be listed on the electrical rating plate that is attached to the side of the kiln or the control case. If you post a picture of that, we can see what it looks like. dw
  19. Given all the disruption from the pandemic, I am not surprised. As Neil notes, probably the first of the parade.
  20. I will stay out of the discussion on how to make one for the lowest price as I am not a gas tech, but if you are looking to retrofit another gas kiln with the Olympic part, I would be very surprised if they would sell it as a separate unit. There is just too much liability surrounding amateur installation of gas valves and burners. JMO, YMMV.
  21. It appears that some of the photographs on the Olympic website show a kiln sitter device on certain models that presumably operated similar to one in an electric kiln, in that a sitter cone inside would bend, causing the flap to drop, which would trigger something to cause a valve on the main gas line to close, and thus turn off the kiln. However, the sales material only offers an optional electronic control, based on a Bartlett 3-key controller that, that as indicated in the instruction manual, will absolutely shut the kiln down at one of 3 predetermined temperatures (1700F, 2000F, or 2350F) should it overfire. But there is also some noise a few pages later that one can program a single set point as the shutoff temperature of one's choosing (though if you understand ceramic firing, you will know that an absolute temperature and a cone are two very different concepts), plus a hold time at that temperature. So, I would guess that notwithstanding the pictures, the kiln sitter option is obsolete and was replaced by the controller.
  22. Try line blending some zircopax into it until it is a white as you prefer.
  23. That is normal behavior. In this situation, the power failure is from being unplugged, and it will immediately report the failure upon receiving power again, i.e, you plugging it back in. Press #1 and the error code will clear.
  24. I built a DIY vent system using a squirrel cage fan originally intended for hydroponics at the output end, standard HVAC vent tubing, and an HVAC Tee joint as the collection box under the kiln. The ambient flow into the collection box is controlled by a standard HVAC in-line damper flap. It's all pretty simple once you realize it's nothing more than a Bernoulli system.
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