Monday, August 11, 2008

Kiln Blues

Well I have run into a little stumbling block with the gas kiln construction. We started digging the footing to pour the concrete slab yesterday and hit a hollow shaft 12 inches down that housed pipes for our waste system. We have this weird system that has to pump the waste uphill because of our rocky and sloping land and the septic fields and pipes seem to be everywhere. We have walked all over this property and can't find a flat place except where the septic fields are or where pipes are very likely laid in the ground.
At this point, I am thinking that maybe I should just buy a Skutt and figure out how to use electric fired glazes. I know very little about cone 04 and cone 6 and would have to do a lot of testing but it might be easier than trying to locate this kiln right now. I'm just going to pause and try to rethink this. It's never simple, is it?


Ron said...

Hey Tracey, I have some catching up to do here on your posts but I'll get to it.
Is the land there so unlevel that you are having to go down 12 inches or more to get a level space? Just wondering, b/c when we built my first kiln we just poured a 4" slab right on top of the land, (leveled and formed in of course). It had no foundation edges or anything. I think it's what is technically known as a floating slab. ?? I then just built the kiln on it.

Also look how Lucien Koonce did it here

Instead of filling that form in w. bricks you could pour concrete. Just a thought, I don't know your situation, but I hope you get it figured out.

Deborah Woods said...

As someone who fires to oxidation using an electric kiln my advice is to not switch because you think it might be easier than figuring a way around this problem. It's been very challenging and an enormous amount of testing to get a glaze palette together. Not that this method of firing should be avoided, there is a lot of beautiful work from electric kilns (look at Ron's work for example), I just think you will be switching from one set of difficult circumstances to another. I know you will figure this out.

tsbroome said...

hi Ron: So good to hear from you!
Everyone has been telling me that I have to dig 12 inches to get the concrete below the frost line to avoid cracks. We had some misgivings about the location because it was so close to the septic units, and now think if we pour slab above any of the pipes and something happens we are screwed for getting repairs. Yes, the land is extremely sloping, we are on a hill (hence the name Chapel Hill I guess) and the only flat parts of land seem to be the septic fields. Geez..........I do like the idea of not having to dig, you wouldn't believe some of the boulders in our yard.

tsbroome said...

I know what you mean. But a good friend of mine reminded me today that this time last year I was doing a sculpture workshop at Arrowmont with Debra Fritts and low fire Earthenware was working for me. For throwing on the wheel, my pots always end up looking like rice bowls and tea bowls and I would like reduction for them. I think that this is becoming a good opportunity to pause and reflect on what the heck it is I really want to make! Good thing is the grant results will not be due in until next July so I have time to work this out the right way.

brandon phillips said...

i also have had floating slabs in both my studios. never a problem. is it possible to put footers on either side of the plumbing? i've known plumbers to dig quite a ways under slabs to fix plumbing problems, that shouldn't be too much of an issue. i think you should go for it, don't give up.

brandon phillips said...

i forgot to say-if you go with a floating slab you should rent a compactor(?) from a local tool rental place to compact the earth, this will minimize your chances for earth shifting. if you have rocky ground its probably quite stable already.

Judy Shreve said...

It's never simple when you are a potter! I too fire to ^6 -- and Deborah is right - everything has it's challenges. Developing a glaze palette, learning your kiln - it all takes work no matter what temp or atmosphere. Hey that's why we love it -- yeah right!

(I'm an apprentice at Roswell Clay where Debra Fritts is director.)

Deborah Woods said...

I can see that. If you are feeling conflicted that reduction is even the direction you want to go right now, and you already feel drawn to working with earthenware, then maybe your heart and your property are trying to send you a message. I don't know you of course, but I'd hate to see you give up this opportunity to build this kiln for something you think may be easier and then regret it. If someone handed me eight grand tomorrow to build a soda kiln? I'd do it in a heartbeat and I'd be scared shitless the whole time. You can always get an electric too, and use it for bisque firing and terra cotta and do both. Sorry, I'm longwinded and opinionated sometimes (most times).

Ron said...

Hey it's me again. I don't think our weather is any different at all from one another and I think there's no reason to dig that deep.

I don't know what the likely hood of any thing happening to your drain line is either. They have to be so far apart too so if you could locate them then maybe you pour a slab big enough for the just the footprint of the kiln. The rest of the floor under the shed could be dirt (if you are building a bigger shed).

My kiln shed is right beside a drain line. (I didn't know it was there when we built the shed. We barely missed it.)

Anyhow good luck. I know it's easy for all of us to give you feedback when we don't know the whole situation, but it would be great to see you get your kiln.

Alan from Argyll Pottery said...

I don't know if you are thinking of a fully mortared kiln but our wood kiln is only stuck at the bottom the hot face insulators are all dry set being held together by the iron work so even if there is some movement over the years you can easily rebuild several times with the same bricks and iron work, we had to renew the fire boxes a few years ago so we took the whole kiln down and turned the white bricks round so they were not too incrusted with ash (bits drop on to the pots after about ten years or so). Our kiln is also on a cement slab so even if it moves the iron work holds it all together. If it were me I still go for it with just a thicker reinfoced base, good luck.

anonymous julie said...

I don't know where you are... up around here (I'm in Chicago) it's 42" down minimum to get below the frost line. I've known people to go both ways. Slab on grade can move if the ground heaves; it's a big problem if the slab is next to something stationary, like a house. If it's tied together well and the ground is prepared well, you're generally okay. (Like most roads, sidewalks, driveways.)

How big are those pipes and how do they intersect your foundation wall? Hopefully in the middle-ish, not at a corner. Concrete block or poured concrete for the wall? You could build the wall over the pipes. This would be easier to draw... um... imagine a doorway in your underground foundation wall, with the pipes going through the doorway, and the doorway only about 6" clear of the pipes on top and sides. Make sense? Make sure you do a header across the pipes to span them, and put loose fill around the pipes so if your kiln structure moves your infrastructure has some breathing room.