Author Topic: Kiln for cooking rock  (Read 7530 times)

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Offline Otoe Bow

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  • Mike Chase, Afghanistan
Kiln for cooking rock
« on: March 03, 2008, 11:25:26 pm »
I was talking to a lady at my work today after showing her my Johnstone point about heat treating rock.  She told me she was looking at a used electric ceramic kiln on Craig's List for $100.  It's pretty small, (inside dimension of about 11"x11"x4"), but you should be able to cook some small spauls fairly easily.  It has a temperature range of between 400 F and 2300 F.   

Since we have so many problems with Burn Bans, wind (and time), I got to thinking it might not be a bad idea to use a kiln.  Do any of you have any experience using one? 

Otoe
So far, I haven't found any Osage or knappable rock over here.  Embrace the suck

Offline mullet

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Re: Kiln for cooking rock
« Reply #1 on: March 03, 2008, 11:29:16 pm »
 Otoe,they work alright  but you need a different themostat so you can bring the temperature up slower. I ruined some real good coral with the one you are talking about. A couple of 50# bags of charcoal work's really good over buried spalls.
Lakeland, Florida
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Offline cowboy

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Re: Kiln for cooking rock
« Reply #2 on: March 03, 2008, 11:31:03 pm »
Not yet Mike: I do have two in the shop but as of yet have'nt wired them up with a rheostat. If your ever around you can load one up for me :).
When you come upon a track or trail you do not know, follow it to the point of knowing.

Offline Wolf Watcher

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Re: Kiln for cooking rock
« Reply #3 on: March 04, 2008, 01:14:44 am »
Otoe:  I have been using a programable kiln for years and if you know what you are cooking it works great.  It ramps up 50 degrees per hour until you reach your cooking temp and then stays there for what ever length of time you want.  Then it ramps down at 50 degrees per hour until you can open it up.  I found cobbles cook at lower temps than preforms or spalls!!  I have a book that tells the degree range of most materials if you know what you are going to cook!
I can send you a copy if you would like!  I started out with a little box kiln and ruined a lot of rock with it.  Wolf Watcher
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Offline D. Tiller

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Re: Kiln for cooking rock
« Reply #4 on: March 04, 2008, 01:45:16 am »
Hmmm! Get the Kiln, role slabs of porcelan and do it in all the colors of the rainbow. Even shape them to the shape you like. Oh! Remember they do shrink by 10% while in the Kiln so make them 10% over the size you would like.  Now there will be no need to go out to hunt flint or obsidian!  :o ;D

David T
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Offline Otoe Bow

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Re: Kiln for cooking rock
« Reply #5 on: March 04, 2008, 01:52:53 am »
Thanks for the info guys.  I think I'll save my money for now and just wait and do it the old fashioned way.  However, I found out from my daughter that the High School Art Department has two pretty sizeable kilns. 

Wolf Watcher, if the info you have is easily sendable via digits, I may see if I can get permission to use the schools. 

I'll keep you posted.

Thanks

So far, I haven't found any Osage or knappable rock over here.  Embrace the suck

Offline billy

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Re: Kiln for cooking rock
« Reply #6 on: March 08, 2008, 02:04:15 pm »
Hey Otoe,

I used to bury my stone in the ground and build fires over them, but they require your time and a lot of wood or charcoal to get results.  Sometimes it wouldn't get hot enough, other times it got too hot and shattered the stone.  It's a lot of trial and error.

Seven years ago my dad bought me a small kiln and I absolutely love it.  It works great and you can control the the temp precisely.  As an added addition, we drilled a small hole in the top and inserted a thermometer into the interior of the kiln.  You can see what the temperature is and control it to exactly the temp you want.  My dad got the kiln from Steve Behrnes out of Louisiana.  It is specifically designed for cooking stone, so it heats up very slowly.  It's almost like those Ronco rotisserie cookers "Set it and forget it".  If you plan on doing any knapping, I would suggest strongly that you get one.  If you don't like it you can put it on the trading post on this website and easily sell it.  Using a kiln will save time, effort, and stone. 
Marietta, Georgia

Offline Otoe Bow

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Re: Kiln for cooking rock
« Reply #7 on: March 09, 2008, 11:59:23 pm »
Thanks Billy, I know what you mean, here it is Sunday night and another weekend got by me and no cooked rocks   :'(.  Do you know the name of the kiln? 

Otoe
So far, I haven't found any Osage or knappable rock over here.  Embrace the suck