neilestrick

You'll need to check the element resistance and see if they're worn. It's a little odd that it would reach cone 4 that quickly but then not reach cone 6 at all, but I wouldn't expect the outside temp to matter, especially since -5C isn't really that cold. Are you sure everything was set properly for the cone 6 firing? Is there a timer on the sitter, and if so are you sure it didn't shut off the kiln?

Is the fan too powerful? Maybe. But I think that if you're using the L&L bypass box and start with just one 3/16" hole in the floor and open the flap all the way to start with there's a good chance you'll be able to dial it down to where it works. You could also put a speed control on the fan, or put a short length of 3" rigid duct coming off the bypass box and put a hole in that to further limit the draw from the kiln. Since you've already got the fan, hook it up and see if it works. You probably won't need a hole in the lid, but I would make a lid hole just to test the draw while you're getting it all figured out.

If it's a throwing class, why are they taking more students than wheels? The mixed levels is not a problem at all. Every class I've ever taken or taught has been mixed levels. I think it's great, because the advanced students pass a lot of knowledge down to the beginners. But for the class to really work well you need everyone to have a wheel.

Since it's porcelain, it's going to warp and sag if you fire it to maturity no matter how you support it. Porcelain gets pretty soft at the peak of the firing, so under-firing it is the only way to keep it from moving about. As for glazing it, the glaze will stick to anything it touches in the firing, so anywhere it's supported will need to be bare, or if you fire it to low fire temps then you could use the metal pointy stilts to support it, however those still leave a small scar. I would go one of 3 routes with this piece: 1. Leave it unglazed and fire it to a 2-3 cones lower than the typical temp for that clay body. 2. Use underglazes on it and fire to low fire temps. Underglazes shouldn't stick much at all at that temp, especially with a good high-alumina wash wherever they touch the shelf/props. 3. Bisque fire it and paint it. (I'd go with this if it were mine)

Welcome to the forum! We need more info to help diagnose this problem. What sort of system is it? Power burners or venturi, Baso valve with thermocouple, automatic system with UV sensors or flame rods or Fireyes? Lots of possible ways to set up a gas burner.

The conversion from 208 to 240 just needs different elements. Totally worth it if the kiln is in good condition.

Is the 563 more yellow than the 630? If you sponge the surface does it get rough?

They were probably not well taken care of. They're not as durable as a brick lid, so they require some extra care. I've worked on a lot of Duncan's with the fiber lids, some were fine, some were junk.

Yeah, that was just the first place I saw a price. I failed to notice their location. Tucker's and PSH have it for $90/lb.

US Pigment has lithium carb for $65/lb, and that recipe only uses 1 pound for a 5 gallon bucket. Where's the $400 coming from?

I've worked on a few more pieces with the new 630, and it seems to be every bit as forgiving as the old formula. Handles and knobs attach well and don't pull away, it tolerates fast drying, etc. Yes, it feels different, but it's still seems to be a very nice body. I'm hoping to fire a few pieces in the next week and see how glazes respond.

If I remember correctly, Amaco used to have some glazes that had fritted lead in them but I don't know if they're still on the market or not.

We use dry cleaner bags in my studio. Leave them double thickness, don't open them up and put the pot inside. They hold the moisture better that way and are easier to remove without mangling the pots. I can leave stuff covered for a couple of weeks without any drying. All it takes is one small gap in the plastic to cause things to dry too quickly. We use 13" and 15" plastic bats in my studio, and put as many pots on a bat as possible, so grocery bags are too small. Dry cleaner bags are big enough to cover everything on the bat and tuck it under all around. If you're using small bats then I don't see why grocery bags wouldn't work just fine. 10-15 years ago I always had a surplus of dry cleaner bags from my students. Now all the offices have gone casual so no one is using the dry cleaners anymore. I did just look and I can get 400+ bags on Amazon for $68, so I might just do that since my current stash is starting to get low. I need about 60 bags in rotation at any given time, and they get torn and dirty after about 6 months of use in the studio, so it would probably be worth the investment.

Get something that is long enough to fit your canopy and your longest tables/shelves, etc. You can get tubs in a large variety of sizes, so you can buy those according to the dimensions of the vehicle, just make sure it's big enough to fit all the stuff you want to take.

Depends on the burner as to what type of orifice it has. Usually they just screw on. Worst case you get a cap and drill it yourself. Depending on the size of the kiln, you may need a fairly large propane tank for it to work properly and not freeze up the tank, so you've got to deal with where to keep the tank, getting it filled, etc. If you have natural gas available use it.

I've worked on lots of kilns where the middle elements don't glow much, and because the kiln wasn't on 100% during the test, that would make them even less likely to glow. If you look at the photo you can see that they're starting to glow, especially at the second element up from the bottom. However it could still be a sticky relay that's the problem.

On a fast fire setting, it makes sense that it would take two hours to to get to 875F, because it's not firing at full speed but rather somewhere in the 500F/hr range, which it may not be able to keep up with.

The controller runs on 24V, so the transformer drops the voltage for it. The transformers is powered at 24 volts AC, but the outputs to the relays are 12 volts DC.

I would say it definitely won't work with that blank section in the middle still open. You'd have to block it off all the way up so just the top two rows are open. And even then it might not fire correctly because Cress typically uses graded elements, where the top and middle elements heat differently. That said if you don't have any shelves in that area, just keep it as one open area, it might be worth a try. You'd lose the kiln sitter, though, so you'd have to use large cones on the shelf and shut it off manually. It's far from ideal. Lots of maybes. The bricks that you block it off the bottom with will need to fit tight, with no gaps.

Does the top ring have elements? What cone are you hoping to fire to?

It's not that simple. It may work, but it may not. The elements are made to create enough heat to heat the chamber, as well as overcome heat loss out the lid and floor. If you take out half the elements, the remaining elements will have to deal with all the heat loss, so now the elements are underpowered for what they need to do. To what degree this is an issue will depend on the size of the kiln and how it's set up. If you have graded elements, where the very top and very bottom element run hotter than the middle elements, by creating a half size kiln it'll be out of balance and won't fire evenly. Also, by adding bricks in the bottom you may throw things out of whack even further. Yes, it'll be more insulation, but it's also more mass. Electric kilns are a bit of a balancing act, where everything is engineered to work a certain way, and when you mess with it things may not work the same. You can always give it a try. It may actually work. If the kiln is very powerful for its size, and the elements are set up the right way, it may be able to handle the change. What model kiln is it?

What firing program are you using to test it? Rate of 9999? There are 6 elements. Since the middle 4 are all running on one relay, then they're not pulling much power and may actually be running as intended. They'll take forever to glow, and even then may only glow lightly. Do a paper test to see if they're heating or not. I'd go ahead and replace the relays regardless, as it's a cheap fix. It could be that the loose connections on the control board were cause a relay to fire improperly, and/or the power supply was sketchy.

You can definitely bisque fire in a typical hi-fire gas kilns, but Raku kilns are tricky for bisque firing. They have a lot of power, and are designed to go fast. You may have to do something like keeping the kiln partially open at the start and slowly closing it. Get as many safety options as they offer.

Those relays still exist: Zoro. Just Google the part number and you'll find them in several places. What's the black box in the bottom of the panel?

EtH shouldn't have been an issue in the first place, so hard to say if it's going to be an issue again. Perhaps cleaning the board solved it. Still need to figure out why it's shutting down and restarting, though. Did you check the fuse holder? You may or may not be able to find those relays if they're really old. Post the part number or a pic of the relay label.