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shoshi

help needed evening out my kiln temp differences

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First firing to cone 5 went well, 6+ hours from candle thru soak.

It does fire hotter on the bottom, about a cone. Bottom dropped about an hour before the top.

That said the cone 5 and cone 4-6 glazes should survive. I'll find out this eve...

 

I'm not understanding why people might be having reduction problems with this unit.

It's harder to actually get it not to reduce when it reaches temp and you want to hold it at soak.

 

More later...

 

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I suspect it's the evenness of the reduction people have trouble with. Mine reduces very well on the top 2/3's, but is a bit oxidised on the bottom. I think that's fixable if you wanted. I agree, oxidation is the harder one, even wide open there is still a lot of excess flame at the flue so...Other than bisque, I don't fire oxidation,so it doesn't really worry me.

 

I like that you're posting pics, thanks. Can never have too much info.

 

I had a bit of a breakthrough myself in the last firing, I used a couple old oversized shelves on the top layers. Though it was going to stall out, didn't need to damper at all. Took a bit longer to get to temp, but it was reduced on the top 5/6th of the kiln. I had heard that before, about putting an empty shelf below the flue...

There are pics of the loading here;

https://www.flickr.com/photos/expatat/albums/72157655647221301

Sorry, haven't figured out how to paste photos here out of Flickr/Pinterest... Oh, also sorry, just looked at the photos and I forgot to upload the shot of my monitor tiles (I put a shino and a copper red test tile on every shelf to gauge the reduction). I'll try to find them and upload.

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Let's try this. FLIKR doesn't have the easy right mouse  'copy image location' allowance.

I've done some HTML so I found it in the code...

Thanks for the input!

 

You load alot of shelves! I've got 5" posts on the bottom of mine at the moment. You seem to be getting good results though.

Cone 5 or ...?

 

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Cool trick Rex. Thanks. No idea how you did it, which is of course what makes a good trick I suppose.

It's ^10 reduction on LPG.

I got the 2831 with an extra ring, so a 2834.5 I guess. Nothing succeeds like excess, or so I've heard. Makes it a bit tricky to load though :). I don't normally use the square shelves, but had a lot of flatware and thought what the heck...Glad I did, firing was one of the better ones so far. I used 6in posts on the bottom layer and 3" /4.5" the rest of the way up.

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Oh, also meant to mention with your setup having the bricks on top. Be careful when you shut the kiln off. These updrafts suck cold air though the kiln like mad. Any gap in the top will allow cold air to be sucked in from the bottom. I lost half a kiln load of bisque a few months ago because my pilot light went out/and shut all my burners off. I didn't have any damper at the time (it was bisque) and the crash cooling caused alot of pieces to crack. (of course I should have been checking the kiln a little more often, but "Game of thrones" was on....). Even without that extreme though, it's generally good to cool slowly from final temp, to give the glazes as much time in liquid phase as possible. I use an old piece of kiln shelf to help seal it up as the supplied "damper brick" doesn't completely cover the flue (at least on mine)...

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Agreed. I build the little chimney on top from 4-8 bricks but I think I'll try it without next firing.

Even after shut down and closing it up I saw a 500 degree drop in about 1/2 hour or so.

I had to light 'er back up to slow down the drop a bit.

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