Troubleshooting my L & L manual Econo Kiln J230

[GrayB]

I’m hoping to get some troubleshooting advise for my kiln. 

It’s an old manual kiln but new to me, I’ve only completed 1 bisque fire (cone 04) and 1 glaze fire (around cone 6) since I’ve had it. The witness cones on my top and middle shelf look consistent, though I did find it odd that the cone 6 and 7 are bent nearly identical, and none of the cones on my bottom shelf bent at all. It had to be at least near cone 5 because the glaze came out looking normal on all my pieces. Visually I think the coils look ok (see picture). I don’t have a multi-meter yet but I noticed that there is a decent sized gap between my bottom ring and the floor of the kiln, and it looks like some of the bricks on the floor could use sealed in between. I just bought kiln cement and I plan to use that on the bottom bricks, would it be ok to use the cement for the gap in between the bottom ring and the floor as well? The gap is there even when the kiln is cool, so it’s not just from heat expansion. Could the gap be my issue or is it more likely an element problem?

Thanks 

[Mark C.]

The gap

looks fine and I would not cement it.Cold bottom is normal as well

[Dick White]

Sometimes even when the elements look good and turn red, they are worn. The only way to definitively determine the health of the element is measure its resistance with a meter. The L&L manual kilns have variable controls for each section. If the bottom is running cool (common), you can compensate for that by have the bottom dial on full high and the middle and top a bit below high. You'll have to experiment with that until you learn exactly how your kiln behaves.

[neilestrick]

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.