Wednesday, September 16, 2009

Groundhog Kiln Firing #4

Judi Munn inside the kiln adding a few more pots to the kiln load. Judi is actually in the kiln firebox. Below her is a metal grate with a couple of boards laid on top. Marvel, one of the other potters participating in this firing, looks on.

Judi climbing out of the kiln. A BEFORE shot of Judi. See here for a photo of Judi AFTER the firing is completed.

A shot of the kiln showing one of the stoking ports. There is a stoking port above the firebox on both sides of the kiln.

During the firing, stoking alternates from side to side. One stoker adds wood, then when the stoker on the other side hears the opposite stoking door close, he/she opens the door on his/her side and also adds wood. Stoking alternates from side to side for safety. A hefty toss could send (has sent) wood straight through the firebox and out the opposite stoking door if both were open at the same time. Throwing wood at your fellow stoker is frowned upon in polite kiln-firing circles, especially considering that after the firing is going good, the wood will ignite on its way through the kiln.

One of the things that's always amazed me about the construction of all conventional wood and gas fired kilns is that they are made with dry stacked brinks. No mortar could hold up to all the expansion and contraction that occurs. Angle iron at the corners and a system of chain and turnbuckles binds the kiln together. The roof is constructed the same way kiln roofs have been for a few thousand years. It is an arch. During construction bricks are stacked on top of a wooden form. Once the keystones are in place, the form is removed and gravity holds everything together.

A view of the pots inside the kiln taken through one of the stoking ports. During the firing wood momentarily rested on the bricks surrounding the port while getting a better grip for tossing will ignite. The stoker is standing only a couple of feet away from this very hot brick. It's hot work.

The last pot is finally loaded and John is building the bag wall. The bag wall reduces the amount of flame from the firebox that goes straight back onto the pots in front of the kiln. 

The completed bag wall. We're finally ready to fire up the kiln.

A larger version of all photos is available by clicking on the photo.

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Mandy said...

That is SOOOOO cool! I'd love to see before and after pictures of some of the pieces, too.

Marvin said...

I'd love to SEE some finished pieces from this kiln load myself. The firing finished up around noon on Saturday, but the kiln couldn't be opened and unloaded until Monday. Our fall art fair season starts soon (this weekend), so we came home Saturday and couldn't spare the time to return to Mountain View for the unloading.

Judi said the firing was good and all Jo's pots turned out fine, except some klutz stepped on a bowl and broke it after it was unloaded. Eventually, we'll get to see the pots, but I really don't know when.