Issues with using a Skutt Envirovent on an L&L Easy-Fire Kiln

A Customer asks:
I recently purchased an E28S-3 kiln from Clay King as a replacement for my old Excel kiln. I have a Skutt EnviroVent system (Metal collection cup under the kiln feeds to an exhaust system – has 2 holes in the cup to mix in air from the room). I watched your vent installation video which gives instructions for drilling the holes in the bottom of the kiln.

My EnviroVent instructions recommend that for a 12 sided, 18” deep kiln, I should drill one hole in the slab and two holes in the lid using a ¼” drill bit. Your video does not address drilling holes in the top of the kiln. I spoke with your representative on the phone who said you do not have top holes for your vented kilns. How does air enter the kiln?

Please advise me on this issue. I am not going to drill any holes (top or bottom) until I hear from you. In the meantime, I will run the initial test fire without the vent system and will just vent the air from the kiln room to the outside.

Thanks

Nancy

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The air comes in mostly through the holes where the elements enter the kiln which provides a nice even distribution. Slightly different philosophy than Skutt.

L&L

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Thanks for your response. I will not drill any top holes and check to see how the kiln draws when I fire it. Do you think I should drill 1 or 2 holes in the bottom slab?

Nancy

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Nancy – we recommend two 1/4″ holes for that kiln.

L&L

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I ran the first firing for my E28S-3 kiln. Everything seemed fine while it was firing. About 15 minutes after it was complete I pressed the Stop button and the kiln started visibly rocking. The same when I pressed the Review button to see the final temp (2158). Everything was installed level and the kiln stand remained stable. But if I barely touched the kiln handle or controller the kiln rocked front to back, like the bottom slab had slightly rounded. Now that it is completely cooled, it is once again sitting flat. I’m afraid to load pots in the kiln for fear that this will happen every time the kiln reaches high temps.

What’s happening?

Nancy

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Nancy –

I have never heard of anything like this.

I am wondering if it has to do with some issue with how the Skutt Envirovent mates with our kiln. They have a very different way of making sure the collection cup mates to the underside to the kiln and our stand if very different. Try firing the kiln without the vent attached and see what you find out.

If this is the problem I am not sure how to fix it but I am happy to work through it with you.

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Ok, I’ll try that and let you know. What do you think about loosening the metal skin on the bottom slab just a little bit to give the brick more room to expand?

Nancy

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No problem with that if you want to try it but I do not think that is the issue

L&L

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I just wanted to give you a follow up to my “rocking” kiln problem. The problem did seem to be the EnviroVent, but, for the life of me, I can’t comprehend the physics of why. I disconnected the collection cup under the kiln, ran a fast cone 5 glaze cycle and the kiln didn’t rock.

I want to use my vent, so I decided to experiment with a different installation. The collection cup sits on a metal post with a strong spring to hold it up against the bottom of the kiln. I removed the post and spring, used a piece of thick kiln insulation blanket to cut a new gasket for the top of the cup that would have some give to it, and braced the cup up against the bottom of the kiln stand with some old kiln brick and a piece of broken kiln shelf. I entered my favorite cone 5 with a hold program and the kiln fired beautifully!!

Thanks for your help. Hopefully, I won’t have any more problems, but it’s nice to know that L & L has such great support!! I’ve been firing electric kilns for over 20 years now and this is my first “brand new” kiln. I’m really looking forward to glazing all the bisqueware that has accumulated in my studio while I dealt with my old temperamental kiln.

Thanks again,

Nancy