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Fiber Lined Kiln Construction


Dinah

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I would love to build a gas kiln or a wood firing design to get to ^10. In fact, that's my next long range plan. There are neat glazes up there, and wonderful effects. I want it all! :D I use electric now at ^6 which is good, make my own glazes, which is good and know that my carbon footprint is smaller than it used to be, which is good. But... I'm a little weary of being good. I've just ordered Fred Olsen's current edition on building kilns, keep revisiting Andrew Holden's The Self Reliant Potter, and ordered M Bailey's Oriental Glazes. Well, we all know what this means don't we! Some wonderful nights watching the stars and the pyrometer. Any other tips would be very welcomed.

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I've built my last kiln for the rest of my life and it was fiber. I will never build another brick kiln and I've built many in the past from catenary arch to sprung arch to flat top, salt, soda etc. Unfortunately, there are no books out there as far as I know, that teach how to build a fiber kiln for a studio potter. In the past two years alone three kiln building books have been published for studio potters and none cover how to build a fiber kiln. This was a major oversight in my opinion but old habits die hard. I know that among some potter's circles moving to a fiber kiln is heresy but my experience dictates otherwise. Most industry is now going to fiber and for good reason, primarily it consumes the least amount of energy if done right.

 

Like any kiln, fiber is not suitable for all situations. For instance, in a classroom setting brick is best because of inevitable student wear and tear. However, for a studio potter who is the only one using the kiln and thus taking the appropriate care in loading/unloading, fiber is best. I get exponentially more firings from a propane tank thru my fiber kiln than I ever did from any brick kiln I've had. And I'm expecting to get at close to a thousand firings from it before I have to replace the fiber, which will be easily done due to the modular design of my kiln.

 

Regarding how my fiber kiln fires. It is perfectly even top to bottom. I fire bisque, glaze, 05 overglaze, reduction, oxidation. With reduction I get perfect copper reds, celadons, blue chun, etc. It's the most dependable kiln I've ever had. It combines the best aspects of both updraft and downdraft. Moreover, there's no bagwall and no stack to have to build. It's worth noting though that there is a learning curve to firing a fiber kiln just like any kiln. For instance, a firing in a fiber kiln will cool down much faster than brick because the fiber doesn't hold heat. That's easily addressed with experience.

 

Regarding cone 10. I'll never fire cone 10 again either. I now fire exclusively cone 6 both oxidation and reduction. For almost 40 yrs. I fired cone 10. I have a binder of hundreds of cone 10 glazes that I've accumulated over that time. Most of them work at cone 6 with some tweaking and some without any tweaking at all. However, due to the efforts of wonderful people like Marcia there is a full palette of cone 6 glazes available for any situation or style. I consider cone 10 to be a holdover from the days of trying to emulate Chinese/Japanese/Korean glazes. Plus many of the porcelains and stoneware clays being fired in China come directly from the soil without additives to lower the firing temps. I have a former student who did a lengthy sabbatical in China and the pottery "village" fired everything to cone 12 because of the particular indigenous porcelain they were using.

 

Most academic institution continue to teach cone 10, I suspect because they don't have to pay for the fuel (the college pays), and most of the teachers would have to relearn what they were taught when they were students. Plus, I could be wrong, but I suspect that there's a certain amount of machismo attached to cone 10. To date, no one has been able to distinguish between my cone 6 and cone 10 pots. Add to that the time factor, which is of utmost importance to a studio potter. The amount of time that it takes to get to cone 10 from cone 6 is almost as long as it takes to get from the beginning of the firing to cone 6.

 

FYI, here's a page from my website with pics of my fiber kiln under construction. The design was a collaboration between me and my friend & potter extraordinaire, Wayne Bates http://www.waynebates.com who has been firing in his fiber kiln for over 30 years.

 

 

http://craigrhodes.u...hodes/Kiln.html

 

I hope this helps in your quest.

Craig Rhodes

 

http://www.craigrhodes.us

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Hank Murrow builds some awesome fiber kilns. http://www.murrow.biz/hank/index.htm

 

 

I've heard that Murrow's kilns are most excellent. BTW my fiber kiln, which I built myself with some help from Wayne, cost around $4,000. However, my brother did the welding for me in trade for pots. Fiber kilns are the true 21st century kilns. Thanks.

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Hank Murrow builds some awesome fiber kilns. http://www.murrow.biz/hank/index.htm

 

 

I've heard that Murrow's kilns are most excellent. BTW my fiber kiln, which I built myself with some help from Wayne, cost around $4,000. However, my brother did the welding for me in trade for pots. Fiber kilns are the true 21st century kilns. Thanks.

 

 

your kiln looks great! Wayne bates taught in Philadelphia after I left, but I admire his work.

 

 

Marcia

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Guest JBaymore

As a professional kiln builder of some almost 40 years I do have to say that fiber lined kilns are "the standard of industry" these days. And Hank Murrow's studio kiln is certainly a "model" for study and possible emulation. Craig's kiln here looks to be nicely fabricated also from what I can see in the images.

 

I think it is important to note here for the more inexperienced readers of this thread that if a ceramist approaches the building of a ceramic fiber lined kiln in the same manner that their experiences with brick kilns have worked, they will NOT be happy with the end results. It is a "different beast". The fabrication techniques necessary are quite a bit different from what one can "get away with" for a brick kiln.

 

For potential reference materials, Regis Brodie did a rather decent book on the construction of fiber kilns a long while ago in 1982 titled "The Energy Efficient Potter". ISBN 0-8230-1614-5. Watson-Guptil. There was another book pre-dating that Brodie one called something like "Space Age Material Kilns" or something like that, but I was not at all a fan of that one.

 

In industry, because of the high volume of firing done in a fixed period of time, the fuel savings from low thermal mass kiln units (along with low mass furniture) compared to even insulating firebirck constructed units is substantial. In a more typical artist's studio setting, one has to weigh the true initial constrruction costs, the poterntial health risks from working with the materials, and the availability of the necessary tools and fabrication skills agains the potential long term fuel savings.

 

I also think it is important to note here for the more inexperienced readers of this thread the following information.

 

Part of the training I give students in my college level kiln design and operation courses includes educating them on the potential toxicological hazards of ALL types of frefractory materials. The respirable free microcrystalline silica dust from all types of refractories is not something to take lightly.... it is a human carcinogen. Working with used refractories is even more hazardous since free silica can be converted to the even more hazardous cristobalite form.

 

However RCF (refractory ceramic fiber.... ie. Kaowool, etc.) in particular has some potential unique concerns above and beyond this. The medical information is not totally definitive on this material, and there are still ongoing questions. The industry is now exploring different fabrications of RCF. One approach that is being explored is fiber that will disolve in lung fluids.... but studies on the effectiveness of that approach in reducing potential issues is in its infancy.

 

Note these specific recommendations from NIOSH:

 

  • Provide safety training about RCF exposure and safe work practices to all exposed workers.
  • Wear respirators to reduce exposures below 0.5 f/cc. For removal of insulation, a full-faced supplied air respirator may be needed.
  • Exposed workers should have periodic medical exams by a qualified physician or health care provider focusing primarily on respiratory health.

This quote is from the U.S. Center For Disease Control:

 

"With increasing production of RCFs, concerns about exposures to airborne fibers prompted animal inhalation studies that have indicated an increased incidence of mesotheliomas in hamsters and lung cancer in rats following exposure to RCFs. Studies of workers who manufacture RCFs have shown a positive association between increased exposure to RCFs and the development of pleural plaques, skin and eye irritation, and respiratory symptoms and conditions (including dyspnea, wheezing, and chronic cough). In addition, current and former RCF production workers have shown decrements in pulmonary function."

Lacking industrial fabrication work's local pickup ventilation controls, (and even with them in industry) exposure to the RCF dusts during kiln construction, repair, and re-lining can be pretty significant. In most studio ceramist settings, actual air monitoring is not typically done. So most ceramists using this material to line kilns or doing repair work have no idea if the NIOSH 0.5 fibers per cubic cenitmeter airborne concentration maximum standard is being exceeded.

 

Exposure to the likely low level dusting from long term exposure in normal operation in studio ceramics for non hard forms of fiber products (blankest, felt, bukk, etc.) has not been studied (to my knowledge).

 

This is a quote from an MSDS for one company's refractory ceramic fiber products:

 

"In October 2001, the International Agency for Research on Cancer (IARC) confirmed that Group 2B (possible human carcinogen) remains the appropriate IARC classification for RCF. The Seventh Annual Report on Carcinogens (1994) prepared by the National Toxicology Program (NTP) classified respirable RCF and glass wool as substances reasonably anticipated to be carcinogens. The American Conference of Governmental Industrial Hygienists (ACGIH) has classified RCF as “A2-Suspected Human Carcinogen.†The Commission of The European Communities (DG XI has classified RCF as a substance that should be regarded as if it is carcinogenic to man. The State of California, pursuant to Proposition 65, The Safe Drinking Water and Toxic Enforcement Act of 1986, has listed “ceramic fibres (airborne fibres of respirable size)†as a chemical known to the State of California to cause cancer. The Canadian Environmental Protection Agency (CEPA) has classified RCF as “probably carcinogenic (group 2). The Canadian Workplace Hazardous Materials Information System (WHMIS) has classified refractory ceramic fibres as a Class D2A - Materials Causing other Toxic Effects."

 

So there are potentially MANY reasons that the use for fiber lined kilns is not yet prevelent in studio ceramics. Many people do not want to yet embrace the potential health issues until "the dust has settled" (pun intended wink.gif ). And many potters are more comfortable working with big clay blocks and slurries of clay-type products than fabricating sheet steel, tack welding module anchors, coating with high temperature epoxy sealers, and so on.

 

Here are some reference resources for those reading this that maybe do not have the technical understanding and training that those who work with these materials typically would have:

 

 

http://www.lhsfna.or...B698984462D75B8

 

 

https://www.ncbi.nlm...les/PMC1128261/

 

 

http://www.cdc.gov/n.../docs/2006-123/

 

 

 

best,

 

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

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Guest Joe the Lion

Let me go out on a limb with this post:

 

I see that, as many threads do on this forum, this one has again drifted off topic. The title is asking for books relating to cone 6 firing. Now, it is about building kilns.

In my view there are two things wrong with this tendency:

1. It dilutes the original topic, and sort of 'closes ' it to further exploration.

2. It might confuse people. Say I read the responses which give advice on kiln building. They are interesting,and great responses, but say I don't really have any use for this info right now.

Six month later, I have need for that info, and want to find it. How am I going to find kiln building information in a thread titled

'Reduction and oxidation Coine 6 chemistry text please'?

You might think I could use the search engine, and I could, but most people do not. Also, the search engine for this forum is rather wanting, and has certain limitations, which might not give me what I seek. That's a different topic, so...

What makes it even worse is that some of the moderators contribute to this tendency, instead of keeping the thread on topic, or moving inappropriate posts to a new thread, as JBaymore has occasionally done.

This board is a fantastic resource, and could be kept so by more stringent organization, I think.

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Guest JBaymore

Let me go out on a limb with this post:

 

I see that, as many threads do on this forum, this one has again drifted off topic. The title is asking for books relating to cone 6 firing. Now, it is about building kilns.

In my view there are two things wrong with this tendency:

1. It dilutes the original topic, and sort of 'closes ' it to further exploration.

2. It might confuse people. Say I read the responses which give advice on kiln building. They are interesting,and great responses, but say I don't really have any use for this info right now.

Six month later, I have need for that info, and want to find it. How am I going to find kiln building information in a thread titled

'Reduction and oxidation Coine 6 chemistry text please'?

You might think I could use the search engine, and I could, but most people do not. Also, the search engine for this forum is rather wanting, and has certain limitations, which might not give me what I seek. That's a different topic, so...

What makes it even worse is that some of the moderators contribute to this tendency, instead of keeping the thread on topic, or moving inappropriate posts to a new thread, as JBaymore has occasionally done.

This board is a fantastic resource, and could be kept so by more stringent organization, I think.

 

 

Joe,

 

You are correct that the divergence off topic happens all the time here. It is hard to prevent. So many things in ceramics are totally inter-related.

 

Yes, I have occasionally moved things.

 

I am still learning how to use the moderation functions of this forum. (Everything in moderation. wink.gif ) I am a very long-term mod on another big forum....... and I know that YABB system inside and out. But this one is quite a bit different. That other forum also allows a lot more available functions than this one does to the Mods. And the Mod user interface is, at least to me, a bit less "intuitive" here. Learning as I go.

 

I'll see if I can split off this "kilns" section of postings into a different seperete thread. No promises. The last time I did something like this .... it caused a bunch of issues tongue.gif . So if we lose all this discussion...... as Han Solo says, "Its' not my fault!".

 

 

best,

 

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

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Guest Joe the Lion

If it didn't work, you could just say what Bart Simpson says :

"It was like that when I got here!"

 

Awesome, awesome,awesome, John! After reading all your posts, I know you are smart and technically inclined, so if you can't do it, who can?

Thank you!

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Thanks much to John for the info as well as health warnings. As in nearly every aspect of clay work, safety is a consideration. It is taken for granted that building any type of kiln will bring with it certain safety hazards that have to be considered. Fiber is no exception. Of course when installing the fiber an approved respirator is a must. But then the same was true when I insulated my studio with fiberglass insulation.

 

Moreover, I had the advantage of living near a friend, Wayne Bates, who had 30+ yrs of building and working with fiber kilns. Add to that the fact that I also have a friend whose job it is to periodically rebuild the kilns at a local factory that makes concrete cement. Furthermore, it is worth noting that fiber technology is improving and changing fast. When or if I do have to change out the fiber in my kiln, I will probably go with the newer rigid fiber board instead of the "cloth". In fact, if I'm not mistaken, Geil Kilns are using fiber board in their line of kilns now instead of cloth. Plus, I do know studio potters using fiber who have made the cloth surface rigid with ITC.

 

There is information out there, even if hard to find, that covers nearly every aspect including safety when building and using a fiber kiln. The safety issues can be as adequately addressed as other pottery issues like free floating silica in the studio are addressed.

 

The point of my post was not necessarily a how-to of all the details in building a fiber kiln but the fact that there is little to no discussion, including recent books, on the benefits of fiber over brick. We live in a time of increasing energy costs and the day is fast approaching, if not already here, in which it will be a primary factor in kiln building. In my experience, fiber is the most energy efficient material for kilns. Industry has already recognized this all over the world. The student I mentioned earlier who was on sabbatical in China was surprised at how many fiber kilns were being built and used in China.

 

Any discussion or consideration of 21st century kilns that does not include fiber is incomplete.

 

 

 

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As you already have cone 6 down and cone 10 is what you want I'll stick to cone 10 only kilns which is where i have the most experience-over a dozen built. Fiber or bricks depends on how hot and what fuels you want to use.As far as books you can glean something from them all as there is no one book-Nils Lou's art of firing should be in that mix-as well as some old studio potter mags. like the minnesota flat top design issue.

If its a wood kiln hard bricks for a lot of it will be needed which will suck BTUs so a good wood source will be needed-this cannot be overstated.

If its a gas cone 10 I suggest a combo soft brick fiber kiln -straight fiber is one way but I love the look of bricks-My current car kiln (easy of loading on back ) is all fiber door -hard brick floor and around all burner ports-soft brick walls and sprung arch and rear wall-If you want the best fuel economy use K23s but keep in mind they will spall over time-I have rebuilt mine with K26 as they hold up much better at cone 11 but do suck some  more BTUs than K23s-When you fire the kiln 90 times a year  for 35 years (bisque and glazes) wear and tear teaches you the best materials as the other ones fail. The outer layer is hard brick as I like the look of that. My bag wall is hard brick-the  two side walls are covered with pinned fiber-I have had the whole thing at one time lined in fiber and like this setup better as fiber can and will cause you a few headaches at super high temps

As noted above by John use of fiber has some precautions which all be overcome.

On our salt kiln its a fiber swing away 360 door with a flat top all fiber 9 inch thick module for the roof we made ourselves by pleating the top and compressing with stainless rods-the kiln is hard brick exterior with mostly soft interior except the bag/floor/burner ports/target brick areas-This kiln is super fast fire and was inspired from a Mel Jacobson CM article years back

Back to a combo kiln- you can layer fiber to make doors and walls but making or buying modules is also a good way to go-We make our own high fire buttons to hold fiber with porcelain clay-I have made many types of buttons and use nichrome wire to pin them.

If you use fiber for cone 10 get the highest rated fiber you can as it all shrinks and you need to know how to incorporate this into the design-I'll gladly tell you all that I have learned over the years with fiber or brick kilns-you can PM me if you want to talk.

I can post some photos if that helps as well-kiln building has been a passion along with clay

You can also go the metal frame fiber way as noted in above post-fuel costs will be less but the brick soul of the kiln is long gone-except the floor which is always brick

I like fiber but the look of brick so I use both-as they both have there place.

One last note is a great source for most of your supplies is Hi Temp in Portland-this little known company is not in most ceramic circles-they can truck up what you need for very low cost and have the materials you need at very competetive prices-

A 1 inch or 2 inch fiber lined brick kiln is super insulated-very economical-

Mark

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