Posts Tagged ‘kilns’

Q and A

Monday, August 16th, 2010

A young potter sent me and email recently with these questions asking for a response. I am posting this publicly in case my thoughts are useful to anyone else.

Next spring my family and I are planning to settle down and open a pottery studio making functional pots that are woodfired and salt glazed. There is a reasonable supply of slab wood for a woodfired kiln available there, Maine. At the moment I am trying to decide what type and size of kiln would be best for me and would like to seek your advice on what kind of kilns are best for a beginning pottery studio primarily making domestic ware for local sales and regional craft fairs. I am trying to figure out how to balance the cost of a new kiln with the amount of pottery it can produce in one firing and the energy and wood involved in firing it.

So far it seems to me a smaller kiln would be the best choice as I can fire it often to increase my skill and knowledge about woodfiring, won’t have to risk months of work when firing and the overhead to build the kiln is lower. But how small is too small?
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I have looked at so many styles of kilns: Olsen fast-fire, train kilns, Phoenix, sprung arch, caternary arch, Minnesota flat top, bourry boxes on all kinds of kilns…there are so many. Recently I have been looking at the “managbigama” kiln designed by John Theis and Bill Van Gilder. It’s basically a small anagama they say fires efficiently to cone 12 in under 12 hours and less than a cord of wood with some ash deposits up front. They say they designed it as a beginner kiln for those who have not built a kiln before (plans available for $300) and haven’t done much woodfiring. But it has 30 cubic feet of stacking space and I wonder if that is enough space…

I would like to ask:
-How many cubic feet of stacking space does your kiln have?

My kiln has two chambers that are about 30-40 cf each.

-How long do you fire it and how much wood does it consume in that time?

I fire on average 15-18 hours and use 3/4 cords of wood.

-How much can you control how much black smoke is emitted? I assume all kilns emit some and while we will be living rurally we do have neighbors in sight and want to minimize the smoke if possible.

For most of the firing I am looking for a more gray smoke but black happens. That is part of woodfiring.

-Does steel make building the kiln easier, or would you advise a design that minimizes the use of steel supports? I have no welding experience.

For the kiln I have steel is just a necessity. I have seen anagamas built with out steel using stones and earth to buttress the arch.

-How quickly does salt firing corrode a kiln? Have you had success with kiln washes to minimize corrosion?

I use about one pound of salt in the second chamber to give color development a boost. I have fired this kiln 72 times and it is holding up well.

-I notice in Phil Roger’s Salt Glazing book, you had a gas kiln for salt firing. Do you prefer salt glazing in a gas kiln to a wood kiln?

I enjoy wood a lot. If my primary interest was salt glazing I would probably not bother with wood as it is time consuming.

-From your experience what are the most important points to think about when considering what kind of kiln to build? I hope I am on the right track, but have little experience and would appreciate any advice on things I may be overlooking.

How often do you want to fire?. I can fill and fire my kiln monthly if I wanted to. As it is I fire about 8 times a year give or take.
What kind of ware are you making. Is it domestic (use oriented)?
What kinds of surfaces do you want?
What will your neighbors tolerate?
What can you afford and what can you build yourself?

-Do you have any advice on what size of kiln may be optimum to support a one person studio making domestic ware for a local market?

I think anywhere between once a month to every other month firing is good. A lot depends on how often you need to have new work rolling through. How you are selling may be a factor.

-What size kiln would you consider to be too small for the time and energy it would take to fire it?

That “managama” seems a little small to me for a potter trying to make a living at it.

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Here is my kiln, designed and built with the help of Kevin Crowe, Nelson County VA.