neilestrick

I've only worked with a couple of Nabertherm, and never a Kiln Care, so all I can say is take a look at what it takes to maintain the kiln, both ease of maintenance and costs. Some companies charge a lot for elements. My very limited experience with Nabertherm is that replacement elements can be quite pricey. Also look at the features of the controller and make sure it does what you want it to do. There are still a number of controllers being used on kilns in Europe that have fairly limited functionality.

What brand and model of wheel is it? Different wheels sometimes need different approaches.

That wouldn't cause the smell, but it's not good practice. It'll cause hot spots on the elements and prevent the heat from radiating into the kiln, and you risk cracking the element grooves. Always keep pots at least 1" from the elements. A good rule of thumb is don't let anything hang over the edge of the kiln shelf.

Running lower amperage through a 50 amp controller relay won't harm it in any way. In fact it'll last longer because of the lower amperage. By the math it looks like you can wire the two main elements in series which puts the total resistance at 15 ohms, and run them on 240 volts (240/15=16 amps). If the single expansion ring element is 35-ish ohms then it runs on 240 volts also. Disconnect the switches and wire the elements directly to the Kiln Sitter terminals. Then plug the kiln into a wall mount controller and you're up and running. You can build your own wall mount with a Genesis Mini controller for about $650 and save yourself a bunch of money.

The smoke effect I'm seeing in your pictures is kind of what I would expect from a kiln that got hot but didn't get over 1000F. The organic materials i the clay were burning up but not burning out completely just yet. I'm not 100% convinced that there wasn't something else burning in the kiln, though. Did you use a different kiln shelf than the first firing, that maybe had something in/on it that was burning out? Where is the kiln located? Was it sitting open between firings, and perhaps some sawdust or something got into it? Inspect all the wiring in the kiln control box, and if everything looks good, try it again. Check the power cord during the firing to make sure it's not getting hot.

Post a picture of the serial plate on the kiln and expansion ring. Also, measure the resistance of each element. How many elements total? According to the info I'm seeing on Paragon's site, there are two elements in the main kiln and two in the expansion ring? You can probably rewire the elements in series and run them off a 3 wire system, but let's see the numbers to make sure.

Not that I recommend firing without some sort of safety shutoff system, but if the sensing rod and cone supports are still there, you can just cram a piece of kiln shelf in there in place of a cone. Or, tape the shutoff weight up so it can't fall and kick out the power button. If you do the tape method you can remove the Sitter tube and fill the hole with fiber or a soft brick plug. It is possible to wire the power cord directly to the switches, but you'll need a terminal block to do that, which is what the Sitter is so there's no good reason to get rid of it. Ultimately you need some sort of shutoff, so it would be worth fixing it.

Yeah that's about the most unstable form you could try to make with porcelain! In bisque it should hold shape okay, but glaze firing is going to be an issue without a lot of support. Without the slot you could probably get it to work, but with that slot pretty much all structural integrity is gone.

So you'll be throwing, and when you stop the wheel with the pedal and start it up again it'll go the opposite direction?

If there was an electrical fire in the kiln, you should be able to find melted wires/connectors in the control box. That should not cause smoke damage inside the kiln itself, though. Most likely there was something burning in the kiln. 1. Any idea how hot the kiln got? 2. Is your kiln vented? 3. Did you have any paper inside any of the pieces, or any wax resist on the work?

Post a picture of the lamp. What slip are you using?

The vast majority of places I see using dry clay to recycle are not actually properly set up to deal with the dust created from using dry clay. If you don't have proper ventilation then don't do it.

Info from L&L, which would apply to most all kilns manufactured in the US: https://hotkilns.com/support/pottery-kiln-faqs/what-gfci-or-gfi-breaker-or-outlet-and-why-might-it-trip-when-used

I've never seen a kiln on a GFCI, and never had an electrician say it was required.

If I remember correctly the DTC and RTC panels are a slightly different size than the V6-CF and Genesis controllers. Bartlett would be able to confirm that. That's not to say you couldn't use them, but you'd have to modify your panel to get them to fit. That may mean cutting the hole for the controller slightly larger, or making a panel to cover the existing hole and cutting a new hole. The V6-CF and Genesis have quick disconnect terminals, whereas the DTC and RTC typically had wiring harnesses with the wires all connected into terminal blocks that plugged into the controller circuit board. So you may have to do some wiring work as well. It's easy enough, just run new wires with quick disconnect terminals. As long as you're spending money on an upgrade, I'd get the Genesis 2.0- no sense upgrading to outdated technology.

If the kiln maxes out at 1700F, then it will only get there if the elements are in new condition. Once they have worn even a little bit, it won't reach temp. 1650F is close enough to 1700 that the same rule applies. Chances are your elements need to be replaced. This is all assuming that the max temp rating of the kiln is accurate and it actually can reach 1700F. As for the programming, the kiln probably won't be able to maintain a ramp of 400F/hr, at least not at the high end. If you want it to go as fast as possible use 9999 because it'll just stay on and won't care how fast it's actually climbing. Also, because you're so close to the max temp of the kiln, it may have a difficult time holding temp at 1650. Expect a certain degree of fluctuation in temp during the hold.

I stopped using Gerstley around 2003 when it disappeared before Laguna started production again. I was working as the clay and glaze tech for A.R.T. clay at the time, and spent a great deal of time helping customers try to reformulate with frits. Unfortunately, there were a lot of recipes out there that used a very high percentage of Gerstley in them and couldn't be reformulated. Most of those were not good glazes from a durability standpoint, though, so it's not all bad that they went away. I regularly get batches of glaze materials donated to me or sold to me for cheap from people in the area who are moving away or simply shutting down there studios for whatever reason, so I've got a few bags right now. I've reformulated some of my class glazes that I usually use 3134 or Gillespie in so that I can use up the Gerstley, but I won't miss it at all when it's gone. I prefer Gillespie or frits. FYI, most industrial ceramics companies won't touch Gerstley because of all the issues that it's had over the years. I was talking with a rep from HC Spinks (they supply Kohler with their clays) one day while working at A.R.T., and someone was talking to a customer about Gerstely and the rep was shocked that we used it, especially that we used it in glazes. He said the only people he knew of that used it in any sort of firing process was the roofing tile industry, which has very broad tolerances.

I've used Gillespie Borate for a long time, and it works great. It tends to be a bit stronger than Gerstley, though, so definitely test. I've found about a 3-5% reduction to be necessary in most of my glazes.

What are you looking for, and what discouraged you?

Your kiln is about 0.6 cubic feet in volume. L&L makes a 0.5cf model, so just slightly smaller, with 3" brick, and at 2160 watts they rate it at cone 6. Their cone 10 model is 2,800 watts. That said, I've got a 0.6cf Evenheat with 2.5" walls and a 2.25" lid that I put 2800 watt elements in and it's got plenty of power to spare getting to cone 6. It could hit cone 10 without struggling in the least. It works about 20% less hard than my larger kilns. So I would think that somewhere around 2400-2500 watts you'd be fine getting to cone 6 and have good element life.

An easy place to start is an equal parts body- koalin, fireclay, ball clay, silica, feldspar- which makes a good cone 10 body. From there you can increase the feldspar to get it down to cone 6. One thing to thing about is where you really want to spend your time as a potter- making clay or making pots. Since you have a resource near you (IMCO) that can mix clay bodies quickly and efficiently while still using local materials, you've got the best of both worlds and it seems like you don't really need to mix clay yourself. Most places that make clay will mix custom bodies, so consider using your Soldner mixing for testing and then having IMCO mix larger volumes for you. Clay mixing and pugging is really miserable work that's really hard on the your body and potentially dangerous to your lungs, so the less of it you can do the better.

This is more than enough to be worried about. Are you sure it's kiln wash and not ITC coating? If it is ITC, then you shouldn't have any problems if it was applied properly. If it's kiln wash, I would be worried about how it will affect the elements, and at some point it will start flaking and the kiln will need to be totally scraped down, which is not an easy project to do without damaging the bricks. She can probably flip the lid slab, but if it's cheap crappy kiln wash it could cause the elements to fuse to the bricks. At some point the kiln will probably be more trouble than it's worth.

You said before that it was chalky after firing, too. Did you mean after the bisque or the glaze firing? How does it look after glaze firing? If it's fine after glaze firing I wouldn't worry about how it looks before firing.

What brand and model of clay is it? What cone are you firing to?

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