floor crack in new kiln

[Frogesan]

Hi, I would like a second opinion about a crack in the floor of my kiln. On the third firing of my L&L e28-S, the floor cracked all the way across (see picture). I wrote to L&L. They said that a crack like that was normal. It seems pretty big to me for a first crack, and I'm surprised it showed up so soon. L&L suggested making sure the steel band around the floor was tight; I was able to tighten it a little so I did that. (It seems to me that the kiln should come with all bands tight, or at least include a note in the manual to check that the bands are tight before firing.) I've fired it twice since then, and I think the crack seems pretty stable -- might be a tiny bit wider but I'm not sure.

Is cracking all the way across on the third firing normal, or should I write to them again?

Thanks!

- Amy

[neilestrick]

It's normal for a slab that big to get cracks in it. You'll get more as your fire more. As long as they don't go all the way through it's nothing to worry about. The best way to make sure they don't become a problem is to make sure your kiln is sitting evenly on all four feet. If the kiln rocks at all, put shims under the feet till the rocking stops. Use sheet metal pieces for shims.

Side note, I see an elements that's sticking out of the holders. Make sure the elements are fully seated at the corners before each firing. After  a few more firings they'll settle into place.

[Frogesan]

Sorry for the late reply -- I went on a much-needed vacation. Thanks for the reassurance. My old Skutt had a few cracks, but it was a used kiln that had been moved a couple times and was at least 15 years old. We made sure the kiln was dead level when we set it up, and when I checked again after the crack showed up it still was. It doesn't rock at all, either. We shimmed the stand with some big fender washers and metal "mending straps" when we assembled everything.

I'll tuck that element back in; I hadn't noticed it popping out. REALLY appreciate you mentioning it!

best,

Amy