neilestrick

The clay suppliers cannot control the quality of their raw materials, nor can they test each bag of raw materials, nor can they really inspect every batch of clay to find chunks in it, especially if the chunks not a certain percentage of the mix. It would be impossible to find them. They rely on their raw materials suppliers to provide quality materials, and they take a risk with every batch of clay they make. But it's they're job to acknowledge that there's a problem and make it right, either through refund or replacement, just like the raw materials suppliers will have to do for them. That's all they can do- be nice about it and make it right. If they can't do that, I would consider finding another supplier (I know that's not a simple thing). Clay is cheap, even when it's expensive, and replacing one ton isn't going to hurt their bottom line at all when they're selling a few million pounds a year. I used to run the clay production lines at A.R.T. clay, and if we found a problem that was not the fault of the potter, we would replace the clay body. One person who bought 100 pounds and had a problem is probably not the clay's fault. Several reports from different studios is probably a clay problem. Chunks of rock would definitely fall into the replacement category, regardless of how many people found it. We once found a hole in the stainless steel liner of our mixer, meaning there was a quarter-sized piece of metal (or several smaller pieces) somewhere in the clay. Bad news. We had to throw out all the clay we had mixed since we last cleaned out the mixer completely and knew there wasn't a hole in it, something like 12,000 pounds.

The last 100C degrees are the most important in terms of how your glazes will melt. Take a look at a cone chart and make sure the final ramp is at the correct rate and target temp for the cone you're trying to achieve.

I would expect a little variation in your settings, but it shouldn't be anything major. Just make sure you get a big enough propane tank.

I can't recommend specific models since I'm a moderator and a kiln distributor, so check out recommendations other have posted here on the forum. There's a lot of info here.

I'd look for a system that uses a cooling fan, not just a heat sink, unless your kiln space is very well cooled. SSR's can burn out if they get too hot, and I don't totally trust a heat sink on its own to do the job, because kiln rooms are typically pretty warm. Beyond that, get a kiln that will be durable and easy to repair.

See HERE. For your mortar, you need a clay that can repeatedly handle the temps of your kiln. So if you're going to fire to 1300C, you want a clay that can go at least a couple hundred degrees higher than that. You don't want a lot of shrinkage in the mortar, although the silica sand will help with that. Of course, we make do with what we have. So if you only have one option, then use it, mixed about 50/50 with silica sand, and keep the mortar joints very thin. If you have good bricks, mix it up as a slip and just dip the edge of the brick in it. If you have uneven bricks then you'll have to go thicker with the mortar to fill the voids.

The Skutt and Genesis/L&L controllers are the same controller as far as the circuit board are concerned, but Skutt puts a different screen on it which drives up the cost, and they also changed the programming that's supposed to make it 'easier', but isn't necessary at all. The Genesis is very straightforward and easy to use and has more functionality than you'll likely ever use. I have not used the TAP controllers, but they appear to be very similiar. In general, SSRs are not really going to pay for themselves in longer life, and for typical firings you're not going to see any difference in the results. The only place they may be beneficial is in crystalline firings where you're doing a lot of climbing and cooling segments where the improved temperature control of the SSR's can help a little bit. The fast cycling of the SSR's allow the temp to deviate less form the target set point, but it's not really a big deal. I have a customer who does cone 10 crystalline work with both setups, and they get great results from both. Personally, I would not spend the money, and there are many other factors that should influence your choice of kiln before that- element life, durability, maintenance costs, etc. In your typical non-crystalline work there's no benefit to having SSR's in terms of fired results. SSR's also do not decrease firing costs in any way. You may get improved element life, but not enough to matter.

Nabertherm kilns are very well built and fire great. However replacing broken bricks can be a challenge due to the way they're constructed, so if you get on you want to be sure to be careful with it. You should also check on the price for replacement elements, because at least here in the US they can be very expensive. If there are other brands of kilns available in your area, compare the prices on elements.

I have used Weebly for a long time and it works well. I use their shopping system, too.

You'll have to call Cress. I think L&L is the only kiln manufacturer that uses the production date for the serial number.

Low fire clay remains porous even after firing. If the glaze has any crazing (crackling) in it, then the water can seep through the small cracks in the glaze and soak into the body.

For the mortar, you can just use fireclay and silica sand. No need for cement or anything like that. Sand should be pure silica sand, not play sand or sand that has other mineral impurities, because the sand could actually melt. Raw clay could work, as long as it can handle the temperatures the kiln will be firing to. Cat litter is bentonite, which wouldn't be good- very sticky, high shrinkage rate.

You'll have to take off the control box to get it apart, but then you can move the upper and lower sections separately, which will be much easier and safer than trying to move it all at once. Just label the wires as you unhook them so you can put it back together properly. Set it on a piece of foam when you move it so you don't break the bricks. House insulating foam board works fine. Did they include the stand? If not, buy one or use cinder blocks. HERE is the manual. Most all manual kilns work the same. Set up the Sitter with the proper cone, then do 1 hour with all switches on low, 1 hour on medium, then high until the Sitter shuts it off. Set the Sitter timer to about 1/2 hour longer than you expect the firing to take (you'll have to do a firing to figure that out). I assume this is going in your home? That kiln currently has elements for 208 volt electrical service. In order to use it at your house you'll need to change them to 240 volt elements. The amperage draw will probably be slightly lower with the new elements, but it will probably need a 60 amp circuit. Call Paragon for elements and to confirm the amperage draw. Kilns must be on a breaker that is 25% greater than the draw of the kiln. If Paragon's elements are pricey, also try Euclids.com.

That should have gotten you to cone 06, maybe even cone 05. It's really more important that it's firing accurately at glaze temps, which it is, so I wouldn't make any changes to the thermocouple offsets. I would just adjust the final temp up 30-40 degrees.

What was the rate of climb for the final 100 degrees?

Check the switches, make sure all the elements are getting power on High.

If the fuse blows immediately upon being plugged in/powered up, then it's probably an issue in low voltage part of the system- transformer, fuse, controller. If it blows immediately when the firing starts, then the problem is in the high voltage part of the system- relays, elements. If it blows when the firing has been going for a while, then the problem is with the service wiring or breaker.

How big is it?

What sort of thermocouple/flame sensor system does it have? Typically when gas kilns shut down unexpectedly it's because of the pilot/thermocouple system. Either the flame is inadequate like Bill showed, or the TC/flame sensor is worn. It's difficult to tell if the thermocouple/flame sensor is worn, so it's easiest to just change it out and see if that helps. Sometimes it's a simple as the TC is no longer properly in the flame path for whatever reason- getting bumped, warping bracket, etc.

Yes, you can use the L&L tubes, you just have to drill out the TC hole. Also, the tubes have a flange on the outside, so L&L uses little ceramic spacers behind the TC block (screws go through them). You need two for each screw, so 4 total. You can see what I'm talking about in THIS VIDEO. Technically you can do it without the spacers, but things snug up better with them.

I don't know who was selling type S for $50, but the ones I get from L&L were at least $150 at their lowest that I remember, about $250 two years ago, and are now $400. In addition to the thermocouple itself, you'll also need type S thermocouple wire all the way back to the controller. Also set your controller for type S. As to whether or not it will last, who knows? It all depends on the thickness of the wire in the sheath and the quality of the construction. Worth a try for $15, though. The other solution to the flaking thermocouple is to install a ceramic protection tube. If you use a closed end tube you'll have to figure out what offset to program in the controller to compensate for the insulation factor (usually around 15 degrees), or you can get an open end tube that still keeps the flakes from getting in the kiln but doesn't require an offset.

Have you tried backing off on everything? Those kilns don't really breathe very well, so they're easy to overpower. If the air is wide open, try closing it down and reducing the gas accordingly to get the atmosphere you want.

What's the gas set at? What temp it is stalling at? How open is the flue? What size shelves are you using, and how are they set up in the kiln? These kilns have always been problematic. Do some searching here on the forum and you'll find a number of solutions. Sometimes people have trouble due to turning the gas up too high. Others say that there has to be a shelf an couple inches below the lid.T he best solution for this type of kiln is THIS, however that may be more work than you want to do.

If you have 18" clearance then the cement board is not needed. If you want it there just to be extra safe, then have it extend about a foot above the top of the kiln. It comes in 3x5 sheets, so 5 feet is just right. It's best to install it with a gap between it and the wallboard behind it, so nail up some thin furring strips first.

No. The top section will connect to both hots, the big section will have the two elements in series.