Jump to content


JBaymore

Member Since 06 Apr 2010
Offline Last Active Today, 10:03 PM
*****

#65372 Wood Fired Kilns

Posted by JBaymore on 30 August 2014 - 09:34 AM

Babs,

 

Wood type can change when firing... but does not always HAVE to. 

 

Sometimes the change is due to limitations in the kiln's design (usually air handling capacity......but sometimes total refractory insulation value).  Soft woods like pine, hemlock, fir and such release their heat very rapidly when compared to hard woods like oak and maple.   So if a specific kiln has trouble getting to temperature at the end of the firing cycle when heat losses are starting to become really significant.... some folks switch to soft wood to do that last litle "push".

 

On a kiln that is being fired for natural ash deposit glazing (shizenyu in Japanese), the chemistry of the different ash from different species cause different effects. So when you switch woods, you get a bit of a "layering" effect on the surfaces developed like layering different glazes.  More subtle... but there.

 

Some folks are lucky enough to be able to fire with a particular wood species for the entire firing.  Just like in ash glazes, the different ash produces different effects.

 

One of my friends in Japan once tried that with a wood known as hiba, a type of cedar.  He had never used that alone before.  It turned out that for a given volume of cords of wood burnt in a firing of the anagama..... that species did not produce all that much ash!  Less than with the other woods he typically fired with (mainly Japanese red pine).  BUT......... the ash that it did produce produced a beautiful yellow shizenyu on the dark reddish clay body (think BIzen-yaki).  Beautiful stuff. 

 

I typically fire my noborigama now with mixed hardwoods.  Oak and maple mainly, with a little birch.  I used to fire it with all scrap sawmill pine and hemlock......... but all of the sawmills in the local area have closed due to the disapearance of  the lumber industry in these parts.  Hard to find that kind of scrap wood around here anymore.  It ticks me off.  I started out usingt wood from a mill about 1 1/2 miles from my kiln.  That scrap wood source radius slowly speread out to about 30 miles over the years.  Now...... I'd have to go very far afield to get that kind of scrap wood anymore.

 

The VERY few mills that still exist around here at all are now set up to instantly chip all the slab and edgings (using fuel) and blow that stuff into a tractor trailer bin... so that it can be sent by a big truck (consuming more fuel) to a central company's location (often a lot of miles away), then use yet more fuel energy to process it into nice consumer-friendly wood pellets, so that it can then be shipped by truck (more fuel energy applied) back to a retail store somewhere, so that it can then be bought by consumers and taken home (more fuel used by the car) and burned in a home pellet stove (that uses electricity to power the auger that feeds the stuff into the stove....more energy applied).  Yeah.... totally absurd.  Just burn the darn wood as wood as close to the original source as possibe!!!!!!.  But they won;t save the stuff for me...... even if I offer to pay an equal price for it to what they get for the ships or even a bit more.  Too much trouble for them.

 

best,

 

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




#65135 How Would You Describe Your Current Studio Location. Suburban Garage, Urban B...

Posted by JBaymore on 26 August 2014 - 02:51 PM

Converted 200 +/- year old barn attached to a center chimney colonial in a formerly rural... now less rural....... section of southern NH. 1000 sq. ft main studio, 1000 sq. ft. materials storage, and 1000 sq. ft. not used yet. Two shed-roofed outbuildings that house kilns. One gas kiln in one, and one noborigama in the other. One small electric kiln, one propane gas kiln, one wood kiln.

 

All sit along the banks of a set of rapids on the Souhegan River. Great sounds and views.

 

best,

 

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




#65115 Irregular Bowls

Posted by JBaymore on 26 August 2014 - 12:21 PM

This will seem contradictory..........

 

First learn to throw incredibly "tight".  Totally and compulsively symmetrical. Like a machine.

 

It will take a long while.

 

Then the loosness you seek is possible.

 

best,

 

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




#64874 New Hampshire Institute Of Art Anagama Build - Images

Posted by JBaymore on 21 August 2014 - 09:44 PM

Day 12 of the NHIA anagama construction with my kiln class came and went today....... with most of us working from 9 AM until about 8:30 PM (along with torrential rain for cleaning up at the end of the day). Today was the "magic moment" wh...en the three sections of main arch forms came out and we officially had an "inside". Front firebox step arches started, more steelwork done, smoke chamber interior wall started, rear wall started, a bit more chimney added above the roof line before the rain, and horizontal flue connection to chimney worked on. Busy and LONG day.
 
That Magic Moment...............
 
ThatMagicMoment.jpg
 
 
FrontStepDownArches.jpg
 
 
WorkingOnSmokeChamberWall.jpg
 
 
GrindingSteel.jpg
 
 
The NHIA Anagama Construction Team 2014
 
The AnagamaTeam2014.jpg
 
 
From the firebox end:
 
InsideAsOf-8-21.jpg
 
 
From the chimney end:
 
InsideFromBackAsOf-8-21.jpg
 
 
best,
 
......................john



#64651 New Hampshire Institute Of Art Anagama Build - Images

Posted by JBaymore on 18 August 2014 - 06:48 AM

Yesterday was Day 8 of the NHIA anagama construction with my kiln class. A slow detail oriented day as we got ready to start on the arch. Test fitting of bricks, leveling the skews with castable, checking positions of features like steelwork, and then starting to lay arch bricks. The chimney also rises.

 

LayingArchBricks-8-17.jpg

 

 

PlanningSteelworkWithKurtHeinzman.jpg

 

 

KilnAsOf-8-17.jpg

 

 

ChimneyRises-8-17.jpg

 

 

 

best,

 

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




#64472 New Hampshire Institute Of Art Anagama Build - Images

Posted by JBaymore on 14 August 2014 - 09:34 PM

And Day 5 is now complete. BEAUTIFUL fall-like weather today.  We did some indoor technical "chalk talk" stuff indoors for the morning, and then resumed hands-on construction in the afternoon.

 

Day 5

 

KilnFront-8-14.jpg

 

 

KilnBack-8-14.jpg

 

 

 

This is a detail shot in which you can see part of the main firebox roaster grate on the left, a hikidashi (kiln withdrawal) port in the middle, and the in-floor air supply for the second step side stoke firebox in the background

.

HikidashiPort-8-14.jpg

 

 

More to come.

 

best,

 

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

 

 




#64412 New Hampshire Institute Of Art Anagama Build - Images

Posted by JBaymore on 13 August 2014 - 09:05 PM

Day 3

 

FloorStarted-8-12.jpg

 

 

 

Chimney-8-12.jpg

 

 

Day 4

 

 

FireboxEnd-8-13.jpg

 

 

NHIA-MoneyAtWork.jpg

 

 

best,

 

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

 




#64331 New Hampshire Institute Of Art Anagama Build - Images

Posted by JBaymore on 11 August 2014 - 10:28 PM

Some people asked me to keep some updates here on out progress.  So...... here are a couple of shots of the first two days of the build:

 

Day One

 

GettingStarted-8-11.jpg

 

 

RoasterArea-8-11.jpg

 

Day Two

 

SecondDay-8-11.jpg

 

 

SecondDay-2-8-11.jpg

 

 

 

More to come in this thread.  Check back every day or so if you are interested.

 

best,

 

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




#64324 Reduction Kiln- Too Early?

Posted by JBaymore on 11 August 2014 - 09:09 PM

Building even a small anagama takes a heck of a lot of of hard and soft bricks that are  roughly $3 each: so a chance to buy any bricks (presuming they are not already totally spalled or odd sized) for anything less than $1 each may be a worthwhile investment in your future !

 

There are roughtly 7000 bricks ( of various sizes/tytpes) in the NHIA anagama were are currently building.

 

When I built my own noborigama about 35+ years ago... I spent almost 2 years amassing the refractories to do that.  Find a good deal (new or used) and buy them and pack them away for later.  A lot of the brick in my kiln came from the Charlestown (MA) Navy Yard when they were closing that down........... if I remember correctly I paid $0.25 each.

 

best,

 

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




#64291 Ki-Seto Glazes

Posted by JBaymore on 11 August 2014 - 06:18 AM

With Ki-Seto ignore the "science".  With a lot of traditional glazes... ignore the science.  ("Reach out with your feelings, Luke".)  The only "measureing stick" that was used traditionally was the eyeball and the piece in typical useage.  Since there are no toxic materials in the glaze... if it is "low silica" or not is not any kind of health issue........ and the Japanese aesthtic accepted (and accepts) the change in object over time (glaze changing sue to instability) as a part of its natural life.

 

Technically that interesting surface in the "best" stuff....... is a techinical defect.  Just like the pinholing in the best shino glazes.

 

The Ki Seto I've seen has faint crazing evident.

 

best,

 

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




#64223 I'll Be A Little "scarse" For The Next 14 Days

Posted by JBaymore on 09 August 2014 - 08:12 PM

Tomorrow we start the 14 day straight build of the New Hampshire Institute of Art anagama with my kiln class. Formal class runs from 9 A til 6 P.... plus the typical time I have to put in outside that as the faculty member teaching it.  So needless to say, I won't be around the forums much for a while.

 

Carry on.  :)

 

best,

 

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




#64197 Potter's Assistant

Posted by JBaymore on 09 August 2014 - 09:53 AM

Judith, 

 

I believe that you are in Europe, yes?  A lot of people's comments, including mine, are likely based in US experiences. 

 

This is like the "apprenticeship" thread that is also recently here somewhere.  This kind of stuff is few and very far between.  It has gotten harder to do this over the past 35 years or so.

 

If a potter agrees to take someone on...... suddenly they are occupying some of their time in doing teaching/training.   Since most potters are single person operations......... when they are tied up teaching..... they are not producing. Nothing is happening in the studio.   So in a very real sense this is costing them money..... and that is BEFORE and ABOVE whatever wages they are paying that person.

 

Then there is the wages factor.  In most places there are minimum wage laws to contend with.  Some people try to skirt them...... but the risk if they get caught is astronomical.  To skirt them legally is a real paperwork and word-smith game.. and is not easy to set up.

 

Then there is the liabilty factor.  If a helper / assistant / apprentice gets hurt on the job..... the potter better have Workman's Compensation insurance.  That stuff is expensive.

 

Then there are workplace laws that are supposed to be complied with.  Organizations like OSHA have standards that DO apply.  For just one example, since pottery involves clay, and clay has free silica content (not to mention glaqzes and such)... the controls that are supposed to be in place for protecting workers are pretty hard to comply with.  As a single potter yourself, you can decide to just work in a pigstye....... but if you bring in an employee....... that has to change.  Or you can be in BIG trouble.

 

When you get done with all of these kinds of considerations....... it is a BIG decision to take someone on.  The fact that some people still do that often means that they are not really schooled in business practices... and often do not KNOW that they are exposing  themselves to these kinds of risks and liabilities.

 

Then just when you get someone trained well...and they are actually creating a Net for you....... they decide to leave and go set up shop themsleves. And in some cases.... competing with you in the same market.

 

There are some folks that DO this well... and they are the "few and far between" folks.

 

To gain the education....... like for many jobs....... you likely will have to invest in it yourself.  College, workshops, books, videos, shared/coop studios where you can observe others working, and so on.

 

best,

 

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




#64170 What Are You Working On?

Posted by JBaymore on 08 August 2014 - 07:19 PM

Pres,

 

Every kiln I build gets me excited still.  They are the largest sculptures I ever do.  ;)   Functional sculptures.

 

best,

 

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




#64136 What Are You Working On?

Posted by JBaymore on 07 August 2014 - 09:44 PM

Baymore-KilnArea-8-7-2014.jpg

 

The anagama site is coming along from the last picture I posted earlier in this thread.  Today we unloaded about 1/2 of the refractories off an 18 wheeler in a torrential downpour (that started when the truck arrived... and which stopped when it left, of course).

 

Starting this Sunday morining... this project....teaching this class...... will occupy 110% of my time for 14 straight days. Then I have one day to rest... and the fall semester starts!!!

 

best,

 

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




#63972 Why Is Our Work Better Than Imported Work?

Posted by JBaymore on 05 August 2014 - 09:06 PM

Hamada Shoji (the great "folk" potter).......... had what amounted to a ceramic engineering degree before he became a potter.

 

I have used his approach as  an inspiration for my approach.  Master the technical... so you can step back and work intuuitively.

 

best,

 

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