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Kristin_Gail

Converting Electric Kiln To Crossdraft Soda

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Kristin_Gail    12

So I've converted another little electric kiln to run propane.  My plan is to use it exclusively, for soda firings (by exclusively I mean I have no other kiln to use - even for bisque, so this one has to work, somehow).

 

I've done two firings - one straight propane, the other with soda (Gail Nichols' method of chunks, but inserted with pieces of tree bark).  They were successful in that nothing blew up (note they weren't bisqued) and they reached them, but not so much for the soda.  The system I currently have is far from perfect, and will probably never work the way it's set up.  (I have three shelf supports placed in front of three separate ports, where I gently place the soda/wood.  It pretty much just sits right there, doesn't disperse through the kiln more than an inch or two.)

 

I'm thinking of remodeling it.  And am wondering:

 

Is there any reason I can't make this thing a cross-draft?  Is there a particular size need for a firebox - a size I wouldn't be able to obtain?  Will a cross-draft concept not work with a flat roof?

 

Here's my thought:  Make two chambers like this fella did:  http://www.youtube.com/watch?v=iD3hcHQrfkY

One for the chimney, as he did, and one on the opposite size of the kiln, but with the board going only part-way up, acting as a bag wall.

 

Having no knowledge of kilns, I'm certain this idea of mine is ridiculous.  But wondering why.  I realize I'd be left with a very small stacking space, but I already have that now, as I'm staggering 1/4-shelves all over the place and leaving large spaces to introduce the soda.  I'm hoping that, if I can do this crossdraft thing, I would 1. Be able to concentrate the soda introduction into one, protected, space - the firebox.  And 2. Have an easier time stacking the shelves - as they would be uniform size and shape, each stacking on top of another (instead of cantilevered between two or three other shelves and the floor).

 

Any help would be so greatly appreciated. 

 

I should add I have another, smaller kiln (the one described above is ~ 7 cu ft and the smaller one is ~ 3 cu ft) that I could use ... Not sure how.  As a firebox, somehow?  Hmm.  Would love to hear any ideas you have.  I might post pics...

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Mark C.    1,797

We spray our salt kiln with saly water.

The soda /water spray works just as good for soda kilns.

Mark

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Kristin_Gail    12

Now, wait.  You guys aren't answering the question!

 

I've tried spraying soda before (in another converted kiln with the same design), but it just hit the pot in front of the stoke hole and sat there, didn't go anywhere else. I can't help thinking it's a problem in the kiln setup.   I'd be happy to try it that way again, though.  

 

The pain/danger in loading the thing is a big concern for me - the shelves are so precarious and confusing to keep pathways open for the flame/soda.  It just shouldn't take me four hours to load a kiln full of 25 cylinders.  I want to be able to stack it vertically.

 

In real crossdraft kilns, do folks spray into the firebox, or other holes in the chamber?

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Mark C.    1,797

I think the inside chimmney is a bad idea-this was discussed early when this video was suggested.I watched that painfully slow video and thought why would one do it that way??

If you want a chimminey cut a hole in side near bottom and add that chimmney to the outside. That will not suck up space inside kiln. The flat top has almost no bearing on any of this. 100 Minnisota flattop kilns prove this out.

 

As far a spraying sode use the burner entrance hole as well as some holes in side walls which you add called spray ports-You will need a few soft brick plugs which are easy to make.

The kiln in video has zero chimney really. If you want cross draft put burner on other side of exit flue undershelves. The trick is to have the sode spray get distributed evenly in a small space -this will take some stacking skills and shelve placement skills

Hope thats your answer

PS introducing soda in a protected space will not get it out on wares-You want it to be more volatile and fly around pots think (like spray paint)Putting it into the flame path or spray ports gets it going everywhere.

Do not forget to make a ring port to see hows the soda is going

Mark

 

pS I think I have a low threshold on slow videos that show little and move like slugs. Maybe it Simons voice and slow English manner but thats painfull for me.

Junk electrics are cheap/free so I suggest trying a few styles to see what works best-please post your results as that follow up can help others

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Kristin_Gail    12

Oh, my.  I'm an idjit on little sleep.  I posted a link to the wrong video.  This is the right one:  http://www.youtube.com/watch?v=vUSvvAtLMsI

I don't think it's Simon Leach?  But what the heck do I know.  If that one moves slow, I apologize - I watched it with the sound off, while my children climbed on me.  It seemed to go quick to me!

 

In any event, I'm now fairly sold on the idea of turning the kiln on its side, like the other link I posted.  I think this will solve my loading/stacking issues, as well as get rid of the updraft system.  And having the chimney on the outside will save loads of stacking space.

 

I'm working on a blog that details all the conversion steps and firing results - when I finish it, I plan to post the info here, too.  I've had such a difficult time finding detailed reports of other similar projects.  It's also tough to get folks to share their information sometimes - which I why I'm so grateful for those of you here who have helped  me so much already.

 

Spraying soda is sounding smarter to me, once I re-design the thing.  No more kiln insides that look like this after a firing:

 

 01.jpg

 

Thank you so very much - again - for answering my newbie questions and helping to set me on the right path.

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Mark C.    1,797

OK I'm really confused both your links show the same kiln standing normally with a chimney inside chamber. No kiln turned sideways in these two vids.

Neither is on its side.

I have no idea why you would turn one sideways as the stress forces will kill it sooner that leaving it stand straight up as thats what they are designed to do.

Also having a flat stacking floor is always a plus which you will loose sideways.

I can see no good reason ever to turn an old electric on its side other than to kiln it fast.

Thats my 2 cents

The kiln jacket which holds it all together will want to oval out and smuss down. 

Let us know how this works out with some still photos not a video please.

I see no issues with stacking in your photo other than you need more long stilts (try soaps)

When you turn the chamber sideways how are you going to stack off multi sided walls?

Mark

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neilestrick    1,381

I agree. Don't turn a round kiln on its side. Just bring the burners in from the bottom like the little Olympic round gas kilns, with a hole in the top for a flue. If you spray the soda solution, it should fill the inside of the kiln with vapor. Never spray it directly at a pot.

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Kristin_Gail    12

This is the link I meant, about the kiln on its side:  http://jessehull.com/2007/09/01/post-fired-reduction-method

 

I know the meandering, racing thoughts of a sleepless person are confusing, frustrating.  Please accept my apologies. 

 

We, too, decided turning my particular kiln on its side was not feasible at all - it's far to fragile and would almost immediately fall apart.

 

I've been eyeing for a couple months now a big boxed-shaped electric, for sale down the road apiece.  Figuring now how I might get it to do what I want.  And want very badly to *not* ask you folks for help with it.  Lest I completely wear out my welcome.

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Mark C.    1,797

Just a note Jessehull mentions he is waiting for a NEW Geil JH 10 kiln which leads me to believe this was just a very temporary deal.

You can do the same thing as I said cut a HOLE IN SIDE WALL add a stack (chimney) and cut your burner hole away from that hole and you have downdraft

Thank for the real link (3rd times a charm)

There are so many things wrong with that setup I'm just going to say he got some nice work out of it waiting for a real downdraft gas kiln.

mark

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neilestrick    1,381

The cube shaped kilns are really easy to turn into downdraft kilns if you know how to weld. Just attach an angle iron frame to hold the chimney. Put in a burner or two from the side and you're good to go.

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oldlady    1,323

has anyone noticed that the jessehull stuff is dated 2009?   what has happened since then?

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Mark C.    1,797

Looks like he graduted in 2005-2006 

did a web seach and all that is around is this old ghost site

with the kiln flipped over

Wonder if he ever got his Geil Kiln?

Wonder if he is still working with clay?

Not loosing any sleep over this mystery I have too many pots to glaze in am.

Mark

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