neilestrick

The only kilns I've ever seen that can fit something that is 6 feet in diameter are wood burning kilns, or a custom built industrial 100 cubic foot electric. I've seen car kilns that are 6' long, but not in width. Large kilns are typically built in rectangles, not squares or circles. Have you already made the piece? You're going to have to enroll in a class or join a studio in order to use their kiln, especially since you'll probably need to use their studio to build it since transporting something that large isn't a good idea. In addition to having a kiln that large, they'll need to have the equipment to move the piece in and out of the kiln. Your other option is to build your own temporary kiln around the piece.

Kiln had a dead relay overnight, so I will not be doing the absorption tests tonight. I did trim a piece I threw with the new 630, and it trims nicely, similar to the old body. It still has the same light grit, as before, but it seems like there are more fine particles. I'm really interested in seeing how the fired color differs, if at all. More updates tomorrow...

I opened up a bag of the new 630 yesterday and tried it out on the wheel. It feels totally different than the original formula. It feels like they took out the fire clay and replaced it with ball clay, although the web site still says it has fireclay in it. It creates a lot of slurry when throwing. Personally, I feel like it has lost most of the properties that made me like it, however it still seemed to throw well. I'm going to give some to my students and see what they think. I don't use it for my work so it doesn't really matter what I think, as long as it is still a forgiving body that's easy to throw and will work well for beginners. I've got a test tile in the kiln right now that I'm going to test for absorption tonight.

I would say that at least 2 of the samples you posted are raw clay. The third it's hard to tell, but it's either raw or has a very dry glaze on it. Personally, I wouldn't want to eat off of any of them. rough dry surfaces are not a pleasure to use or clean. A matte glaze can't be transparent, but a satin glaze can be (mostly). It's a balancing act. Dark underglazes can come through a satin transparent, but lighter colors can get hazy. If you're looking for something as matte as the samples you posted, you won't get transparency. The surfaces and colors you're seeing in the examples are coming from the clay.

What information is on the serial plate- voltage, amps, max temp, etc? Manual attached. IM-112_E_&_Q_Inst_&_Service_Manual.pdf

Fire it just like any other manual kiln. Put all 3 sections on Low for 1-2 hours, Medium for an hour, then High until the cone drops. If you need to dry things out, crack the lid and set the bottom section to low for a few hours or even overnight. Looks like the top ring is a blank ring without elements, which may lower the max temp that the kiln can reach. If you're just firing to low fire temps it'll be fine.

What type of bat system? Is it too small for the total diameter of the wheel head, or for the bat pin spacing? Assuming Brent makes them the same for the European market as they do for the US market, the CXC would have a 14in/355.6cm wheel head, with holes for bat pins drilled at 10in/25.4cm on center.

In addition to broken element grooves, the color of the bricks is a pretty good indicator of age and condition. New bricks are a light cream color, old bricks turn yellow and become soft and brittle. The darker the yellow, the worse they are. I had this very conversation with a customer a couple of weeks ago. The bricks in their kiln were in halfway decent condition in terms of breakage, but they all had little chips in them and a few of them needed replacing due to large chips. Plus it needed elements, relays, feeder wires, and a wiring harness. It was going to be a $800 repair, which would have been fine if the bricks better, but they were all very yellowed and super soft and brittle, and weren't likely to make it through the repair without further damage, or last as long as the new elements. We had talked about replacing it the last time I worked on it, so they were prepared for the bad news and ordered a new kiln.

All models are available with Quad elements without any change to the power requirements, so you can get the e28T-3 with Quads- you don't have to get the eQuad model that has higher power.

I've seen kilns that were destroyed in 3 years and less than 200 firings, and I've seen kilns (like one of mine) that have gone more than 2,000 firings without changing a single brick. It all depends on how they're cared for and how they're constructed. Personally, I don't like using kilns specifically for bisque or glaze because every time you change the elements you do damage to the bricks (in non-L&L kilns), and the glaze kiln bricks don't last as long because they're always firing really hot (in any brand). So the glaze kilns get really beat up and the bisque kilns last forever. I think if you're doing both bisque and glaze in all the kilns you'll get a better lifespan from all the kilns as a whole, and won't have to live with half your kilns being crappy for years and years. I get being able to fit the smaller bisque kiln load into the bigger glaze kiln, but I would consider having two or three e28T-3 and one or two e23T-3 and using them all for both types of firings. If you load the big kilns with bisque you can reduce the total number of loads needed. The L&L e28T-3 kilns will need a 50 amp breaker, whereas your current Skutt 1227 kilns only need a 40 amp breaker, so take a look at your electrical panel and see if that's doable. In the long run it'll be well worth the cost to upgrade the wiring for the cone 10 kilns, but make sure your center is willing to do that. Get the quad element upgrade for any kilns you're using for glaze. It'll pay for itself. The Genesis 2.0 controller is now standard on all L&L kilns!

Have you confirmed that the BTU output of the burners is enough for your kiln? What sort of safety system will you be using- Baso valve? Conversion kilns of this type generally have a lot of issues with firing evenly or reducing evenly or even getting to temperature. The biggest issue is that people try to utilize the interior space like they would with an electric kiln, which doesn't work well at all. You have to have more space for air flow, so smaller shelves are usually needed. One of the best conversion designs is THIS ONE. With an oval you have the advantage of being able to make one end the flue and still have a fair amount of stacking space.

What type of burners- venturi or powered?

Definitely. I made a lot of mistakes when setting up my business. I received all of my training in the university system, which at the time (1990-1997) was heavily focused on cone 10 reduction and selling in galleries. So when I set up my gallery/studio/classroom in 2004, I did it the only way I knew how: I built a gas kiln, found galleries to sell my work, and taught my classes with the same methods I had learned in school. None of that worked out very well. Galleries were closing left and right, the gas kiln was not at all practical for my business, and students weren't interested in the rigorous class structure I was trained in. So after 4 years in my original location, I made the decision to radically alter my business model. I moved to a location that was about 1/3 of the size and got rid of the big gallery space. I stopped selling other artist's work, bought a couple of electric kilns, and changed the way I approach my classes. I also started doing art fairs, which were a big problem in the academic world I was trained in- they were the realm of hobby potters, not serious artists. I also started really advertising kiln repair services. Finally everything started to fall into place with my business, after 4 years of struggling. So my big regret is that it took me a long time to see past my training and consider other ways of running my business. To be fair, it was a difficult time to open any small business. When I opened in 2004, traditional methods of advertising- print ads, phone books, etc- were on their way out and ridiculously expensive, but the internet hadn't quite picked up the slack yet. Facebook was just getting started, Instagram didn't exist yet, and DYI website builders were barely available and not very good. It was going to be difficult no matter what, but my lack of flexibility made it worse. I should have started smaller, jumped into cone 6 from the start, and considered other methods of selling. In regards to clay work itself, no regrets. I've focused on a lot of different techniques over the years, and every one has made me a better potter.

Thanks for posting a pic. To me that looks like a coating of crappy kiln wash flaking off. Some cheap washes will start to fuse like that and eventually flake off. Unfortunately, you'll have to grind it off, although you may be able to scrape a good amount of it off first. When it's clean and smooth again, re-wash them with a decent high-alumina wash.

It looks like someone blew up a bunch of terra cotta in the kiln. If there's that many shards in the bottom of the kiln, there's also going to be a bunch of shards in the element grooves, too, and it's going to be nearly impossible to get them all cleaned out while there are elements in there. If there are any shards left in there, they are going to melt if you fire the kiln up to cone 5/6 and fuse the elements to the bricks. Plus, if the control box is that rusted, I would bet everything inside the box is pretty corroded, too, and depending on what type of controls this particular Cress has, it can be an expensive fix. I'd walk away from this kiln.

@Fawn This is a good point. 30" is fairly big, so make sure it'll fit in your space.

Hi @KLackler, welcome to the forum! Can you post a pic of your shelves? Is it just a layer of wash flaking off, or is the shelf itself delaminating or something weird like that? What type of shelf- silicon carbide, cordierite, etc?

Assuming the wiring diagram above is the correct one for your kiln, you've got 3 sets of elements and only two infinite switches, so you'll need to add one more switch. Just drill into the box and put it wherever it fits. The top section and middle section can connect directly to an infinite switch. The bottom section cannot connect directly to a switch because infinite switches max out at 15 amps and the bottom section pulls 22amps. So for the bottom section you'll have to use a relay as a go-between. The infinite switch will cycle the relay on and off. You may be be able to re-use one of the relays currently in the kiln.

The Shimpo 30" slab roller is made in China by Friendly Manufacturing Corp (FREMA). Over the years it's been sold by Ceramic Supply, Axner, and others. It's still currently sold by Pottery Supply House in Canada. It's a good slab roller. I used to sell them, and several of my students and customers have them and they've been good machines, especially for the price. For a home studio it's a great choice. I probably wouldn't get one for a studio where it's going to have a lot of heavy use, though. For a heavy use studio I would go with the NorthStar Super series or a Bailey.

Soda/salt does not attack silica on its own. Plain silica is quite resistant to salt/soda effects. It's the silica/alumina/salt eutectic that causes the glaze to form. We used to dust silica onto the shelves for salt firings instead of using wash. That said, I would use a high alumina wash as stated. I think a 50/50 wash is more likely to shrink away and flake off, though, so I would calcine half the kaolin.

Welcome to the overly-complicated world of Duncan Kilns! I can't get you any definitive answer on how to diagnose the timers on these old kilns. IMO, the best option is to do away with the timers completely and convert it to a standard manual kiln with either 3-way or infinite switches. Some of these timers are still available, but apparently some of them are not. There are a number of folks here on the forum who tinker with these kiln, so someone should be able to help.

The smell may come from the preservatives they use. All commercial glaze products contain a biocide to preserve the gum, and each company seems to use a different one, because each brand has a different odor. The underglaze transfers that are made by hand in the US use commercial underglazes, often the Amaco Velvet line.

Hi Paul, welcome to the forum. Can you post a picture or two of the controls? Does the controller have a model number or brand name on it that's different from the kiln brand?

Ah, you mean the thermocouple itself, not the wires that connect it to the controller. Yes, if that hole is too small then the TC could touch the metal.

Definitely a mesh size problem. The larger mesh size won't burn out properly, hence the crater effect. Copper reds are typically pretty fluid, so you may need to adjust the thickness of the glaze application or your firing schedule.