neilestrick

A waster slab should do the trick, or put some silica sand on the shelf. Make sure you put kiln wash or alumina wax on the waster slab so the tile doesn't stick to it. If you need a cooling ramp it would be during quartz inversion, so from about 1100 to 900, but it's rare that you would need that.

It's odd to have a gap between sections like that. It could very well be the cause of the problem down there, or at least a partial cause. There are ways to fix that with some work on the bricks, but the easy solution would be to lay a thin layer of fiber under the bottom row of bricks, to seal up any gaps. Lay it all the way around, full width of the bricks, and set the ring on it. It'll compress where the bricks fit tight, and fill gaps where they're not. I would not try to mortar the gap. Smear some mortar in the floor cracks. Not a big deal. Did you have a shelf at the bottom? You need one down there, up on 1/2" posts. Otherwise the bottom will definitely run cold. When you load the kiln, at the bottom you should put low mass pots like bowls or tall pieces, pack the middle section really tight, put whatever's left at the top, preferably semi-tight. Also check your elements with a meter to see if their resistance is correct. Could be the bottom is worn more than the others, which is not uncommon.

Take off the bottom cover and see if the belt came off or broke.

There are always exceptions to the rule, but I would not recommend trying that again. Glad it worked out for you!

Those shrinkage rates are more than close enough for what you're doing, and those numbers are way too precise. There will always be slight differences in shrinkage depending on the accuracy of the firing, the thickness of the pieces, etc, so for them to give a number that precise is totally unnecessary. They basically have the same shrinkage rate.

What type of kiln is it? If it has a door, just pull the obvara and then close it up and finish the raku pieces. Otherwise I think you'd probably be fine just firing up to raku temps and pulling the raku pieces first while the obvara cools a bit. It's not an exact temperature anyway, since the pieces cools some between the kiln and the bucket, and the last piece is always a lot cooler than the first.

Unless you make it considerably thicker, porcelain is going to warp with a form like that.

On a regular manual kiln the drop and hold is near impossible. On this kiln not possible at all. It's the realm of digital controllers.

These kilns fire fast. Probably not a stuck relay for that model based on your description. There has been a lot of discussion about them here on the forum. HERE is a great thread that will give you lots of info.

Computer fans work great for this application. There's already a grill in place on the box, so measure that and get a fan that fits. This is a small enough box that the output of the fan won't matter. Amazon carries a bunch for very low prices.

Is there a fan on the outside of the case that we can't see in the photos? Definitely need a fan to keep the SSR cool.

Not everyone wants to or is able to throw dinner plates on the wheel. I slab build my plates, and it is much faster than throwing and I don't have problems with humping in the middle. @chris123 I think the issue is either with glaze tension as mentioned above, or it could be from uneven heating/cooling between the edges and the center or the top and bottom. 1. Does it happen with all of your glazes or just one? 2. What size kiln do you have, and what firing schedule are you using?

@Retxy are you digging your own clay or are you buying raw materials (or both)?

I'd remove the control panel and take off the insulating baffle and see if it's dry inside. If it's still damp, let it sit open for a day or two indoors so the electronics can dry out completely. You do not have to have the elements connected to the kiln to test the control box, and should not if the bricks are still wet. You will need to have the thermocouple connected if you want the controller to do anything besides read FAIL.

I'd replace the element. Even ground down there's not going to be much you can clamp onto there. Better to have a good connection.

I'm afraid I kind of agree with BlueBird. If it has half dollar size holes in it due to corrosion, the rest of it is probably not structurally sound. The non-pugmill option is to simply not wedge and not recycle. Most clay bodies are good to go for throwing right out of the bag. I switched to slab building about a year ago after 30 years of throwing, due to bad arthritis in my hands. Gotta say I don't really miss throwing. I'm happy to still be working with clay, and the challenges and possibilities of working with new techniques have me more excited about ceramics than I have been in a long time.

Just a thought, but depending on how much space there is around the auger and how this is constructed, you may be able to weld in sheet of steel as a liner.

CI made the larger wheels like the MP and HP main structure from plastic, and coated the wheel heads. The Clay Boss has more metal, but the head is still coated. I wouldn't use heat.

Results will be the same, but they may or may not use the same elements for each wiring setup. By the math if you wire the single phase as three phase it's going to pull 18.5 amps, not 10, so I don't know what's going on there. Very different wire size requirements for those amperages, too. It doesn't appear to be as simple as just picking one or the other.

Call them directly if you can. We only have a handful of folks in Europe who regularly participate in the forum who may have knowledge of that particular kiln. One of them may chime in, but your best bet is always the manufacturer. As far as single 3 or phase goes, look though the wiring diagrams and see what the amperage draw is for each setup, as that will determine what size breaker you need. Follow local codes for properly sizing the breaker. Unfortunately they didn't color code their wiring diagram, so that's going to make things more difficult.

I highly recommend you contact the manufacturer before rewiring this. Switching between single and 3 phase will affect amperage draw, and may require new elements or wiring as a result. Without direct knowledge of this kiln we can't make any recommendations here. They can also tell you which thermocouple you need.

The touch screen itself is about $600 as a retrofit for their old digital controller, but you would need an entire control box assembly which will cost about $1250 plus shipping. It would replace the entire cream control box on your kiln. A Skutt KMT822 box may fit your kiln, but it would probably need to be wired up like a KMT818 since your kiln has two zones and the 822 has 3. Your Kiln Sitter looks to be in very good condition other than the missing knob, so it may work just fine. Age isn't such an issue with kilns as much as usage. Yours looks to have had very little use.

I have seen freishly glazed pieces blow up in a raku kiln. Unlike a regular electric kiln firing, the kiln heats fast enough that the pots don't have a chance to dry out before steam happens. When I used to do raku workshops, newly glazed pots were set on top of the kiln to dry out before they went into the kiln. Once the kiln was heated up from the first firing, the bricks held enough heat that the kiln would rocket up to 800F within a minute as soon as the door was closed without even turning on the burners, so pots were set into the kiln with the door open for about 10 minutes to heat up slowly at first at get that last bit of moisture out of them. We also set the pots on cold pieces of soft brick so as not to shock the bottoms, pulling out the hot ones after each firing and replacing them with cold ones.

I would definitely paint the outside with a good quality spray paint. The inside is going to rust no matter what if it's steel, so it's best to use it regularly so the rust doesn't build up.

Yes. And the 1 hour preheat actually takes about 3 hours because it takes about 2 hours to get to the preheat temperature before it starts the preheat time. Try a cone offset of about -15 degrees for starters. You're not over by much.