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Dawn

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2006 Past President
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What do you do when all the pots just turn black (or really dark colored)?  This is the number one problem teachers trying the Saggar Fire Project have encountered.  The main reason: students love to put EVERYTHING in the saggar.  Too full = too much smoke = black.

 

First, you can re-bisque the work to cone 06 to remove the carbon black.  Then re-saggar it.

 

When it come to the saggar fire, there are a number of solutions.  If your work is too dark, apply two of these solutions first, then add one more at a time until the desired coloration is reached.  Applying all these solutions will result in very light, almost white pieces.

 

Solutions:

 

1.  Eliminate all the ingredients that make black (sawdust, fine steel wool and copper wire) or substitute color creating equivalents:  Use dry leaves instead of sawdust, course steel wool instead of fine steel wool, eliminate copper wire/copper scrub pads.  Bananna peals make a lovely dark brick red, but should be eliminated for lighter colors. 

 

2.  Be aware of where the ingredients touch the pottery, especially the ones that make black.  My shallow bowl pictured below shows where the ingredients were piled (black mark).  The rest of the bowl is colored by the smoke from those ingredients.  A tall piece in a tall saggar (or small pieces stacked in a tall saggar) can take advantage of this by coloring the bottom of the piece black fading to bright colors at the top.    

 

3.  Give the smoke some space by using a larger saggar.  I like having 1/2 my saggar filled with my pottery and ingredients leaving 1/2 of the saggar empty to allow the smoke room to move.  If working with kids who wont stop until the saggar is full, ingredients that leave a lot of air space will help.  Dry leaves, tiny branches with many forks, wood shaving curls instead of sawdust create air pockets. 

 

4.  Cracks or holes in the saggar allow some smoke to escape making the work lighter in color.  Gap size can be larger or smaller to control color, but a 1 inch gaop is a good place to start.  NOTE:  This is why you should always think twice before discarding rejected bisqueware.  Bisqware bowls with a s-crack in the bottom make great saggars and s-cracked plates make great lids.

 

Easy Way: slide the lid to the side to allow a 1 inch gap or use a lid that is broken and open the crack an inch.  I often use broken kiln shelves or square slabs of clay as saggar lids.  They create a flat surface so the saggars can be stacked, but the a square-ish lid does not actually cover the round saggar leaving gaps for the smoke to escape.  (See the Easy Saggar post for more ideas on saggars.) 

 

Hard Way:  Create a saggar with 1 inch holes drilled in various places.  Create plugs for the holes at the same time so that ventillation can be carefully controlled.

 

5.  Use a bisqueware bowl to suspend the piece over the pile of ingredients in the bottom of the saggar.  This allows the work to be colored by the smoke  with nothing actually touching the piece.  Artist Lara Carroll used this technique on the tiny vase, below.  She wrapped the vase in a single strand of course steel wool and placed it in a bowl on top of everything else in the saggar.  After saggar firing, the vase was then "feather fired" to create the feather imprint. 

 

Please post any other solutions you find.  -Dawn Atkin



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Dawn Atkin
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