Wayne2

Neat - great work. I have been using a spreadsheet to analyze our kiln files. Your system is faster, but some strange things appear in the plot with only one TC in the file. If you are still looking for files - I have posted one here as csv files seem not to be allowed here. https://drive.google.com/file/d/1lqPtwFqCxZJqssNqVqIMdFKyUaXpQSFL/view?usp=sharing

You don't mention if the glaze is a commercial one or one you make yourself? Tony Hansen (digitalfire.com look at the glossary for Drop-and-Soak Firing ) says one can drop 100 -200 degrees to the hold dependant on the glaze and one has to experiment to get a fit to the glaze. We have been using 100 degrees and that has helped our glaze surfaces. The larger drop probably won't negatively affect other glazes (other than increasing matteness of matte glazes). That being said, the loss of EPK and substitution of Tile#6 or Diamond has increased bubble production in the clear we have been using for several years now and thicker sections are more impacted by those bubbles and they turn the glaze whiter with less clarity. Changing that drop will likely help. PS You also didn't mention if you use cones to check your controller, what kind and your firing rate in the last step. Depending on your controller/kiln you may be firing a bit high, We have seen what seems to be a bit of correlation with fewer bubbles on shelves with lower temperatures and comments on another link on these fora seem to suggest that may be another thing to explore. look at the "holds at end of firing" thread in Equipment Use and Repair

One can also add a bit of gum solution to fix crawling in a dipping glaze. You don't want to add too much so better to try on a smaller sample. This may not work if you have lowered the specific gravity though See https://digitalfire.com/material/228 Note that if you buy any prepared gum solution it may not be the same as the gum solution discussed here. A bit of some bactericide such as Detol to prevent the bacteria from eating the CMC is needed if you store the gum solution (or the modified glaze).

Thanks Neil, I agree with your comments and expect all the relays need replacing and the thermocouple connections need to be checked/cleaned. The hotspot is a great idea to try before working on a more permanent solution and using a laptop to connect to that hotspot rather than the router (which it normally does) is something I wouldn't have tried. As the controller is not reporting a MAC address I have assumed this is a hardware issue. Your earilier comment on the WiFi module supports that assumption. Next time I am in the studio, I will also check if the controller is actually broadcasting a signal and the strength of the router's signal in the kiln room.

Thanks that is a good thing to check and a good fix. I will check the signal strength. Actually that second run was underfired (didn't reach a good cone 5 when the first firing overfired to Cone 7+) which makes this so perplexing.

Thanks. On a longer term I am wondering if changes are needed for a firing schedule to accomodate any kiln's recent performance. So at a lower ramp speed in the top segment, when the programmed temperature is reached the load could be overfired? Here is a picture of the graph from the controller of the second firing. Assuming that the controller/thermocouples are getting the right temperature, the graph suggests the kiln rose from 121C to 1098C in ~8-9 hours--if it was 9 hours very roughly a ramp speed of ~110C/hour. Any idea of if and how much that final segment's actual ramp would be lower than the initial ramp at higher temperature? Would it be different than the program's called for speed of 60C/hr or would it be totally random depending on the relays being stuck open or closed?

It might be. Its hard to think in color rather than controller temperature. While a change in the mass in the kiln changes the heat-work required, my expectation is that it would change the achievable ramp speed in a 'challenged' kiln in an inverse manner (higher mass=lower speed). That lower ramp speed would also lower what the controller sees as the temperature for a Cone firing perhaps requiring changes to that firing schedule (and one reason why I want to get that WiFi data to find out the real ramp speed). The second firing (50 degrees C lower temperature according to the controller) had lower mass and took two hours longer. Given the kiln and shelves have a relatively constant mass, shouldn't a smaller load need less heat-work and take less time to heat up and less time to cool too? My guess is that a problem in connection resistance or arcing would probably have a similar affect (perhaps increasing resistance and decreasing heating rates with time until something fails) during each firing. Does relay sticking vary in effect this much between 2 firings?

Hi, Thanks very much for your response. I was wondering those climbing rates might be too high for that kiln and you have confirmed that suspicion. The mass in that second load was smaller than the first so I suspect your thought on connections or relays (and/or potentially mother board) may be correct. I am not sure of the warranty status of that controller and will check that with the powers that be. If it is off warranty I suspect a new controller would be the best option. I am looking forward to getting some better data off the controllers once the WiFi works. The thermocouples all seem to be reading within a few degrees of each other in any of the screens showing temperature. Cone packs from the second firing had only minor difference between the zones. I was thinking a minor thermocouple offset might be in order, but now that I think about it, I did not check the mass in each zone. Other than that data from the WiFi/downloaded logs, I am not really sure what log/data item that would tell me that a section was lagging? I am not at the studio now and will check the data menu log for the relay cycling later this week once the weather clears here. I did not notice there was a last error code on that screen and will recheck that (and also that error codes have not been turned off by someone.) Thanks again Wayne

Hi, I am not new to programming computers, but I am new to programming kilns and have learned a lot from the postings in this group. Thanks to all who have posted. Kiln-an older three zone Cone Art Kiln BX 2327-1. Elements (6) are relatively new and have been obtained from reputable sources. The controller is a Bartlett Genesis Model LT3140. Its printout: Software 3.26.0 Serial 799801015 network genesis Type K max temp 1315C We tried the C6IRED Firing Schedule from Digital Fire, (top temperature is 1204C or 2200F), but the cone packs (large cones) in all 3 zones were fired to over cone 7, which if I am interpreting the Orton temperature charts correctly is over 1255C. The firing took a bit over 12 hours (Insight suggests it should be around 9:51). Despite the cone pack evidence, the graph output from the controller suggests that it did what it was programmed to do, going a bit over 1200C. This kiln is in a group pottery and we fired another load to keep up the output. I assumed a linear thermocouple response and subtracted 50C from the peak, shoulders, and that last segment of the C6IRED numbers, leaving the ramp speeds the same. The kiln just reached Cone 5 and the firing took almost 14 hours (Insight suggests it should have been around 9:36.) I am not totally sure what really needs fixing but suspect it may be the motherboard. My first thought it was a thermocouple issue, but the controller hasn’t indicated a failure and they do not look corroded. They are what the local pottery store sells for the kiln, unmarked 8 gauge type K inserts. The second thought i that it is the motherboard. It was replaced about a year ago, but may be either misconfigured or failing. Aside from the over firing, the WiFi is not working and its acceptance of user input seems a little spotty/irregular. While it says it is searching for networks and the WiFi light on the front panel flashes regularly, there is no MAC address listed in the controller and it never finds the router. Rebooting re-configuring WiFi as per the Bartlett web page says doesn’t seem to make any difference. When starting up the last Bartlett automatic Cone firing the controller did not allow the change from a “fast” to “medium” firing. One other thing; there is apparently confusion on the length of time used for these firings. I have been told a longer firing for a lower temperature is what one should expect when I questioned those firing times. That is counter intuitive to my expectations, as I would expect it should take less time to reach a lower temperature. I also tend to think Insight’s numbers should be closer to the time for firing if the kiln was working properly and the elements in good shape.