neilestrick

Did you get the pull-apart option, or does it have the spring mounted hinge and the control box attached to the kiln? There's no way to load that without unstacking the sections. You'd have to remove the hinge plate and lid, remove the control box, then unstack the top two rings, load those sections, then add the other rings and load those. Are the jumper wires and thermocouple wires long enough that you could remount the control box lower down, so you could make the top two rings removable without having to remove the control box each time?

You can, but the thing I don't like about the Skutt lid brace is that it's only on one side, so the lid twists a little when braced, which puts a lot of pressure on the wall bricks. You could put a brace on both sides, but that gets really awkward when trying to close it. Instead of the braces I would hang a chain and hook above the kiln to hook onto the handle and hold the lid.

I wouldn't allow anything that thick in my wood kiln, even with organic inclusions. If it blows up you're going to have your shards stuck to everyone else's work. A successful bisque firing for something that thick will take a few days. Do the owner of the kiln know they're that thick? They should be hollowed out, for sure.

The things being discussed here is are not necessary to good glaze formulation. I've been making durable glazes for 30 years without ever looking at a Stull chart or Katz's papers. Learning the basic of glaze formulation- fluxes, stabilizers, and glass formers- will serve you just fine, and allow for tweaking formulas to increase durability and adjust glaze fit for your clay body. Commercial glazes are not necessarily any more durable. They all take testing as well. Clear glazes are generally quite safe if they're free of lead and cadmium, which most all glaze recipes being used nowadays are, and they don't have the heavy metals (colorants) in them that are likely to leach in a poorly formulated glaze. The benefits of mixing your own glazes are that they are much less expensive, and you can alter them as needed to fit the clay body you're using. If you know another potter that has a good clear glaze, by all means ask them for a recipe.

@Ja.Sc. It's not normal to have any holes in the lid and floor other than the very small holes for the vent system. Were they just vent sized holes, like 1/4"? The breaker size will not affect the firing, however the breaker may trip. If you have the correct size wiring (6ga) then you can just swap out the breaker for a 60. Have you run a paper test to make sure all the elements are heating up? Place a small piece of paper on each element, let the kiln run for a bit, just enough to make the paper smolder, then turn it off and see if all the papers have burned a little. If both element in a section have not heated, then you've probably got a dead relay in that section. If that's the case, replace all the relays. Also check the condition of the wiring in the control box. If the wiring or connectors are starting to darken go ahead and put in a new wiring harness when you do the relays.

@Ariel23 I suggest changing the title of your post to better reflect the content so you get more replies. Definitely check the program and see if you accidentally put in cone 6 instead of 06. If the controller said it only got to 1400F but it melted cone 06 to a blob, then check if the controller is set for F or C, and also check to make sure it's set to the correct type of thermocouple that you have.

Whether or not it will deform depends on how thick the piece is and how soft your porcelain gets in the firing. Lots of variables there, so your best bet is to test it.

@hotzn I'm still not understanding. Is this a sculpture or is it functional in some way? What will the final product look like? How many pipes will there be? Why is this draft tolerance needed? Can they be joined after forming or do they have to be formed together? What are the dimensions of each pipe? How large is the grouping? What shape is the grouping? Are they all connected at the bottom, top, sides? What are the total dimensions? The function of the final product will determine which type of clay you need to use. There's also issues of warping in drying and firing, etc. "Normal pottery equipment" is not really good for things that require precise tolerances since things move. Is clay the best material for this project?

Most likely the 45 amps is for the entire thing, as that would be a typical amperage draw for a 23x27 kiln. To be 100% sure you'd need to measure the resistance of the elements, but I'd be pretty confident that the entire setup is 45 amps. So you'll need a 60 amp breaker, 6 gauge wire. It's a 3 wire system- 2 hots and 1 ground, no neutral. Should have a NEMA 6-50 plug/outlet. How's the condition of the jumper cord that connects the two sections? If it's the old cloth wrapped stuff or the plug is looking corroded I would change it out. You'd need a 12 gauge cord for that 15 amp section. Put some insulating sleeves on the wire ends inside the box. If the plug is corroded I would also replace the outlet it plugs into. That would be a 20 amp 240 volt outlet.

@sunil6784 Also, what is the total interior height of the kiln sections? 27" base plus a 9" ring, or a 18" base with a 9" ring?

Post a pic of the serial plates.

Can you please define draft angle? And will this be sculptural or will it serve a function? A drawing, maybe?

Looks like typical thickness blowouts to me. I've seen them in that location before. I'm surprised that the preheat didn't prevent it, but that could be related to the location in the kiln, stacking, and how quickly the firing ramped after the preheat.

Usually when connections overheat like that it reduces the power draw, however if it it arcing then it's possible that it could cause the breaker to blow. I would cut back the power cord to fresh wire and reinstall it and see if that solves the problem. If not then replace the breaker.

Dana's build is really nice, but it doesn't have to be that complex. They used solid state relays, which are sexy, but don't give you any real benefits in terms of firing. SSR's also complicate the build because they have additional cooling requirements. If you're familiar with SSR systems then by all means go for it, but otherwise I would just do a mechanical relay that can handle the amperage of the whole system (usually needs a pilot relay, too), and make a simple single zone setup.

There are 2 elements per ring in a Skutt kiln. Each element loops twice. On low the switch sends power through both elements in series, creating 1/4 the available power. On medium it send power through one element, so 1/2 power. On high it turns on both elements in parallel for full power. The controller regulates the temperature by cycling the relays/elements on and off. However you can't just swap the Sitter with a controller and put some relays in the box. The existing box is not made to house a digital system. It's not vented well enough and there's no heat baffle. If you want to convert it to a digital system you'll need to build a separate box and mount it to the wall. The kiln plugs into the box and the box plugs into the outlet. Look at the Skutt KM-1 wall mount controller as an option. That type of system uses one big relay to run everything rather than individual relays for each section. Or you can buy a complete new digital box from Skutt, with their controller. For the money I'd replace the whole box so you don't have to deal with having the manual system and the digital system.

I've had good luck with the connectors you show above, and ConeArt uses them in all their kilns. Are those tinned copper? I usually use raw copper, as does ConeArt. Not sure if that matters or not. One tip, make sure you're putting the wire at the bottom in the V and the element at the top, so the bolt pushes on the element. That'll give a tight connection. You may also need to re-tighten them after the first few firings just to be safe. Bending the end of the element into a circle and putting a bolt through it is a great connection. Use stainless steel, put a washer on each side, use a lock washer, and connect the feeder wire to it with a high temp ring terminal. Totally old school and very good. I'd use a 10-24 bolt.

Lots of great discussion here, but we still don't know what the blowouts look like, where they were on the piece, etc. OP has abandoned us. Personally, I've never considered compression to be the cause for blowouts. They are typically caused by foreign bodies in the clay or moisture. I don't see why compression, platelets alignment, etc, would cause a section to violently separate from the piece.

GFCI outlets are not recommended for use with kilns. See HERE.

@THW Aha! It's not an 8 tab, it's a 6 tab with a double connector. Okay, so that all good then. We just couldn't tell from the photo. In that case double check all the crimps and see if that helps. A bad crimp could definitely cause the relay to overheat and fail.

Try again. I approved your account.

@Bubba The plug definitely needs to be replaced, but I would go ahead and replace the entire power cord. Could be that they didn't have it on the correct size wiring, which was causing the outlet and plug to overheat, but who knows. Plugs wear out over time, so it's not all that unusual to have to replace it. If the kiln is very low priced, then even if you have to replace some stuff you'll be coming out way ahead over a new kiln. As long as the bricks and lid/floor are in good condition the rest if it is relatively easy and inexpensive to fix compared to buying new.

The relay in these pictures is different than the relay you currently have installed. The 6 tab is the correct one, not the 8 tab that's currently installed. I would hook up the 6 tab, following the wiring diagram.

On hi they probably won't cycle, they'll just stay on. If they're staying on but it's not hitting temperature, then the elements are probably worn. Are you sure the switches were installed properly? If I remember correctly they are installed upside down in these kilns. The best solution to making these kilns work well is to simply gut them and replace all the switches with infinite switches wired directly to the elements and sitter, no relays or timers.

Yep. If you put it on Ceramic it's basically just staying on medium. You need to set it to hi fire.