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PuckGoodfellow

Home-Made Kiln Question

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As some of you may know from my other thread.. i'm working on building my own propane kiln and a woodfire kiln so i can have access to multiple firing methods at my home.  B)

 

I also wanted to be able to cast my own metal molds so i could press clay easily, so i built a crucible with an empty propane tank (it never had anything flammable in it), a couple bags of quicrete, a 2 and one half foot steal pipe and a bellows (hair dryer works good to). it works GREAT(i'll give greater details if anybody is interested)! But that's not why i'm writing this thread.

 

While watching videos on YouTube.. I came across a guy that built a small woodfire kiln with 8 concrete blocks (the thin type), 1 steel screen (for the second level shelf), 4 bricks, 1 small steel plate/sheet and a butt load of wood chips/shavings. all he did was build a 4 block square, filled it with pottery, stuffed it with wood chips, laid down the screen, placed 4 more blocks, filled & stuffed (as before), placed the 4 small bricks kiddie-cornered on the edges, lit the chips on fire, placed the sheet on top and walked away. the video didn't show him pulling the pieces out so i didn't get to see how well it worked. Have any of you ever tried this method? If not..

 

What backyard kiln methods HAVE you tried (if any)?

 

Once again..

Any and all feedback would be most welcome  ^_^

Thank you in advance.

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I feel the need to say that heating concrete above 300 C/575 F is a bad idea.  It can explosively spall and decomposes into caustic materials that react exothermically with water.  Its reactions to the gases of fire are also a big question mark.  I would feel terrible if anyone got a chemical burn due to heating concrete.

Marcia Selsor and timbo_heff like this

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Thank for that piece of info. I had asked around before building it but nobody could give me any info about how the quicrete would react to heat. I should have googled it. I don't know why I didn't. I'm glad I already have my molds cast and nothing bad happened.

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I feel the need to say that heating concrete above 300 C/575 F is a bad idea.  It can explosively spall and decomposes into caustic materials that react exothermically with water.  Its reactions to the gases of fire are also a big question mark.  I would feel terrible if anyone got a chemical burn due to heating concrete.

 

 

On facebook, Louis Katz just recently posted some images of the explosion (in Thailand) of a small wood kiln that was built on a concrete pad and the folks that built that kiln under-insulated the floor (common mistake).  Good solid orange color inside when it finally went BLOOEY!  LUCKILY no one was injured........ but the glowing mess and sparks and such made for some impressive pictures.

 

I've heard of a couple instances here in the US of that same thing happening with wood kilns improperly constructed on concrete foundations. 

 

Don't get serious kiln heat into concrete folks!  Bad things can happen.

 

The "root" cause of this mess.... the thing that "everyone knows".........  'Heat Rises'.  NO.... it does NOT.  Heat energy moves equally in ALL directions from areas of higher concentration to areas of lower concentration. (basic laws of thermodynamics)  If you decide you need X inches of some insulation configuration in the walls and roof of the kiln... then you need the SAME X inches in the FLOOR of the kiln. 

 

If the hot face of the roof bricks are at X degrees, then the same heat energy is leaking thru them as what is happening at the floor bricks hot face.  Simple really.

 

Hot gases rise when suspended in cooler gases........ hence our "experiential" core belief that "heat rises".  That nice heat from our woodstove seems to head for the ceiling of our homes.  It is the lighter hot air that is rising thru and above the cooler air.

 

best,

 

...........................john

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Puck, I think it might be best if you take a class or two in ceramics and metal working.  It's exceedingly difficult to tell you what you're looking to know through a limited form of communication like an internet forum.  There's a lot of subtlety to working in both media that's much easier to show that to explain over the internet.  Even the most comprehensive answer anyone here could give will have unintentional omissions and that could spell ruined work or worse, injury.

 

I really admire your eagerness to learn and your very lofty goals. I can safely say that everyone here is willing to help you achieve your goals, but you might need a little few fundamentals under your belt before we can really be of full use to you.

 

For your melting furnace, find some "Mizzou" castable refractory.  That's what you want to use.  Flux resistant, high temp durable, and definitely NOT explosive. :)  ANH is the manufacturer, I believe.

Colby Charpentier likes this

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I second Tyler's suggestion of taking a class, or gaining some type of experience before engaging in archaic and dangerous activities that lack financial viability.

 

In Rhode Island, your options are Dew Claw Studios, The Steel Yard, Mad Dog Studios, South County Art Association, Jamestown Arts Center, or Mudstone Studios. None of these programs are built by mountain men living off the land, but they could at least teach you a bit about clay, kilns, and so on. If you can afford it, there are courses at RISD, RIC, and CCRI. You won't necessarily learn more at these programs, but their facilities will tend to be larger.

 

Also, re-think pressing clay into metal molds. You tend to see molds made of porous materials so the clay will release.

 

Good Luck...

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Colby. Thank you so much. I needed that list. Sadly.. At the moment. I'm beyond broke but I have all tools needed to get started. Just can't afford school. Trust me.. I want to go to school and learn everything I can. It's just not in my budget (for now). That's why I want to find a simple molding and firing method that I can use while I try to raise funds for school. As for the metal molds.. I was watching a video of a woman making traditional Irish clay pipes and she used a metal mold that she had to put in a gin press. I want to be able make my pipes and mugs so I can finally have a living that makes me happy. I've never done well with 9-5 jobs (finding them or keeping them). I would be a painter right now but I destroyed the nerves in my dominant hand. I can't draw anymore but I can sculpt. I want/need clay to be my life. But I can't let a lack of funds stop me (or I will never get to where I want to be). So maybe, knowing this (sorry to just drop it all like that) you guys may be able to suggest an easy (and safe) small wood burning kiln that I could use to get started. My local dug clay isn't quite where I want it to be so I have decided to order some earthen clay to use for now but I don't know which cone I should buy. One day I will have the skill to be an old timey potter but for now I just need to be making SOMETHING. I know I need schooling (and it IS on the list) but I need to act. I can't think about anything else. Its just clay 24/7

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Puck, 

 

If you're really sincere about making a living from ceramics, you'll go for that class time.  I know it's expensive and I understand that money's tight, but you're going to waste far more of your earning potential on the self-learning way.  Ceramics are all about failure--remember that.  There are also just as many bad ideas on Youtube and the web as there are quality ones.

 

I think I went through about ten 25 lb boxes of clay before I got anywhere near the quality I wanted.  Along with that, probably a few 100 lb tanks of propane for my kiln.  With all the other things I had to buy along the way, I'd be surprised if I didn't spend $1000 in self-education expenses--that's WITH a few courses in it as well.  The actual courses cost less than a quarter of that.  Without those courses I probably would have spent ten times as much money.  In addition, I got a priceless education in things like safety, glaze chem., and business advice.  

 

Think about what it would do to your earning potential if your melting furnace had exploded on you.  You could have injured yourself badly--permanently.  Not to mention the potential to do damage to your property or your neighbours.  Am I right in assuming you have no liability insurance?  A fire or explosion could have put you out of business for a long long time.

 

Not trying to be a downer, just trying to get you on the right path.  You'll be much further ahead for a few classes.  Especially with things like wood firing.  That's a tough thing to get right and likely the most expensive form of firing there is.

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A wood fire kiln, will still require some supplies to create, not to mention the expertise to build and run it.

 

I built a Raku kiln for a couple hundred dollars, but those aren't efficient for bisquing.

 

Finding a fellow artist, or art studio, with a kiln you could share, would probably be the best bet.

 

Otherwise, you could purchase some air dry, or oven hardened clay, to satisfy you artistic need to create.

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It sounds to me like you are talking about extruding rather than molding. I went to an old ceramic pipe factory where they used their old equipment to extrude pipes and form them into great plant pots.

 

I am sure you could build a simple press and get some kind of results but that would involve money too unless you have lots of spare metal/wood lying around and the tools.

You could try building a kiln but you would be a lot better off just buying an old electric kiln to start with.

 

Finding a ceramics course may seem expensive but in my opinion it would be cheaper and more worth while than blindly jumping into this discipline but where is the fun in that  ;)

 

How injured is your hand? Ceramics requires lots of work with the hands.

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i have an electric kiln but it hasn't been fired up in 10+ years. i imagine i would have to have it serviced first. I want to have a wood fire kiln because i like the way the clay gets blackened with soot. as for the extruder.. nope. i'm wanting molds so i can press pipes (tobacco pipes).

 

update..

 

I talked my uncle and he (surprisingly) agreed to help some.  i signed up for a 4 day 32 hour beginners workshop for $115.00. It's a start :)

 

I have also ordered some mizzou and chipped the quicrete out of my crucible. No explosions for me.  :wacko:

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There are other ways to "buy in" to the experiences and information you desire.

  • Look into the places Colby mentioned (post#11), I know there are places (museums & Community programs) in my area that have scholarship opportunities (Low to no $).
  • Start hanging around Studios/Programs, meet people (Free).
  • Get on the local university's clay/metal club email lists - show up for visiting artists (Free).
  • Ask about helping out (volunteer) around studio with cleaning and general labor like mixing clay (Free).
  • Show up to Firings/Pours with some food and beverage, make friends and ASK QUESTIONS.

Basically, remember these are community based activities, No one will just give you what you want, but they can help you find out what you need to know (and don't know to ask) if you involve yourself in the community. These places exist because they want to share their skills and experience, don't waste money and personal injury guessing.

 

My two cents.

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I'm sure your local library has some books on pottery.  Even if it doesn't look like what your interested in, read it anyways.  You will be surprised at what you learn.  Read EVERYTHING on this website.  Have you read the all the a info on CAD.  This info could answer a lot of your questions.  I am about three years into throwing.  This after 30 years of doing art.  I just now feel like some, only some, of my work is of good enough quality to sell.

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chantay, thanks for being the first to mention the FREE  library books puck could get.  I am usually the first to mention that to anyone looking for GOOD info.  the problem is that some of the best books on the subjects needed are OLD!  at least to you young'ns.  some of the stuff getting published today is ok if you already know your way around the mistakes that are in them, newbies don't.

 

puck, look for some of the older, textbook type editions of John Kenny, Glenn C. Nelson and others.  yes, there are tiny mentions of things like lead glazes but surely you are smart enough to learn around that.  the skinny books of today that talk only about one shape or style are good for experienced folks but once you have read a LOT of the thicker ones and found a clay that makes you happy, they will make more sense.

 

yes, utube has some good instruction.  it depends on who is doing the work.  (one I saw that was done by someone who had taken one lesson and was willing to share her enormous amount of knowledge was laughable.)  the trouble is that until you can recognize the good ones, you might just follow instructions over the edge of a cliff.  as you watch, ask yourself questions so you know why someone is doing what you see.  following blindly is dangerous.   experiment carefully and welcome to the wonderfully addicting world of those of us who LOVE clay.   

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 the trouble is that until you can recognize the good ones, you might just follow instructions over the edge of a cliff. 

 

Amen, and amen, and amen!

 

My pet peeve with the impact of the internet. Lots of information.... but not necessarily GOOD information.

 

This is why academic institutiions shun Wikipediia as a source for any serious research.  The "crowdsourcing" of information is not necessarily accurate at any point in time.

 

best,

 

................john

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Whoa, whoa, whoa John!  Don't be bad mouthing internet sources.

 

"Wikipedia is a perfectly valid source of information"

 

Source- Wikipedia

 

 

Your move Mr. Baymore

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