Nov 2017 Kiln News

Ceramics
#42

Nichrome is standard bead rack rod material and having a local cheap source for it is great to know. We’ll keep Tanner’s in mind.

It will survive well beyond our glaze temperature, but it’s really rated to be used below it. I’ve seen max operating temperatures ranging from 1650 to 2100. Nichrome turns green or sometimes black when fired. This makes it resistant to oxidation at high temperatures but can leave stains. It also off gasses chromium which can react with glaze.

Lots of folks use nichrome rod with no issues, don’t mind the off gassing or the staining. Others cover the stains with enamel paint or some other way. Nichrome is a good way to go in those cases as it cheaper.

If the nichrome properties aren’t acceptable, Kanthal A1 is the go to alternative. Amazon has 25’ of 18 gauge for $7, enough for plenty of rods. That’s the thickest they seem to carry. The local vape or hobby shops may carry thicker wire. I think the 18 will work fine though.

Anyone using the FA bead racks don’t need to supply nichrome rods unless a smaller diameter is needed.

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#43

Did the kiln get unloaded today as planned?

#44

I don’t have a complete answer yet for what is going on but here’s what I can tell you:

Our big kiln just experienced the same problem as the small kiln. It never reached temp and therefore did not shut off. It made it to 2160 (~5) and then stalled. Basic troubleshooting points to a voltage problem. Both circuits were tested, one under load, and that looked okay. There was a nigh upon unconnected…connector on the small kiln and once attached, the kiln just now fired to one degree short of temp and then did not shut off. Tomorrow the big kiln will be checked under load and the controller cracked open.

What this means: The big kiln glaze load didn’t hit cone six temp but was overfired. Letting it get absolutely room temp before unloading.

I’ll keep everyone updated as I get more information, there will be a delay on firing pieces until we figure what the hell is going on.

A big thank you to @dallasmagna for the electrical work!

#45

Well crap, fingers crossed my teapots are ok. When do you plan to unload? Perhaps my luck will happen twice since it did not go over temp.

I have 2 thoughts on this issue

  1. Was there any other equipment running that would cause a draw on the power or the program to hold? Perhaps in the jewelry Dept.? Is that a dedicated source of power for the kilns?

  2. Not pointing the finger, just looking at the information provided. I believe the kiln has been firing fine when Beth sets it. Could something had been set differently or programmed out of sequence?

#46

I believe the kilns because they draw so much power are on their own drops.

Also, I doubt J&SM would have their furnace on for a long period like the kilns that would prevent them from peaking. But just my thoughts (but suspect VECTOR had couple of machines on so blame them)

#47

  1. As I understand it, David is correct, they are on their own drops.

  2. No offense taken, it was my first thought as well. It was not a custom schedule, it was the standard cone firing. The same one I have used on multiple successful firings in November and have posted the cones for. I had someone else review the firing program just to double check me and I took video of the program review for when I call Paragon tomorrow. If you’d like to see it I wouldn’t mind at all. The Firing schedule: Cone 6, preheat 0, std, 10 min hold (.10), cool std.

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#48

When will you be opening up the kiln?

#49

Glaze kiln unloaded last night.

I’m headed back up now to call Paragon and meet with Chuck. Will post when I have new information.

#50

Were the glazed items damaged?

#51

Just sent you a text with specifics for yours. Colors are very dark, most pieces did not stick. Glazes did run in excess.

#52

Ugh that just gives me a horrible lump in my stomach. I did test glazes sample piece for both teapots to pick the perfect glaze to make sure everything was just right before firing. No runs were on my test pieces, the prolong temp exposure was likely the downfall.

#53

After going through the video again and doing some math I believe I have figured out what went wrong. I would like to sincerely apologize as the mistake was mine. I am very sorry.

To fix this for the future, I will be printing out an instruction card that is free of extraneous information to use. I always program with the broad guide on my phone but my brain just jumped for some reason on this. I’ve fired this program multiple times before but what went wrong was that I put std instead of the degrees for the cool down. This caused the long hold at the top and overfire.

I know everyone puts so much effort and work into their pieces and I am so very sorry. If there is anything I can do, please let me know.

Thank you to Chuck and the other gentleman that helped today, I’m sorry for your loss of time that could be spent on your own projects.

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#54

Just loaded a bisque kiln. The items that are left were a bit damp.

@meanbaby – I got the face in. The genie bottle turned out to be too tall for that shelf, and too big to easily fit a shelf down. Next time. And we may have to set the lighthouse on the bottom.

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#55

Bisque kiln has been unloaded. There’s a big bowl that’s sitting on the greenware shelf, but all the rest of the bisque made it onto the main bisque shelf. Major stacking. Oh, and all of @meanbaby’s stuff went onto the cart.

The ornament class should be by tonight to glaze ornaments. That in mind, I’m planning on loading glaze tomorrow (Friday).

I’d exhort you all to glaze stuff, but there’s probably already a full kiln…

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