Raku Reaction (Raku Workshop Part 2)

Fire and smoke.

In my previous post, Red Hot Raku (Raku Workshop, Part 1), the kiln was king.  You can bet we listened carefully when our amazing instructor, Peter Syak, guided us through the reduction process!  Even so, when we were on “bucket brigade” and handled our pieces just transferred from the kiln, the heat seeped right through our extra-thick, fire-retardent gloves.  I had to rip the gloves off and fan my fingers!

Guess what happens when ANYTHING touches a surface that’s 1800 degrees F?  It bursts into flames!

Here are some pictures of the process.  Hon, stand back from the fire…unless you’re on “bucket brigade.”

Beds are prepped and waiting for our hand-built and wheel-thrown pieces.

Peter calls lifting the kiln lid “a dance!”

 

 

 

 

 

Peter uses long, metal tongs to remove our red hot pieces.  He QUICKLY and CAREFULLY places each piece in a spot on the sawdust bed.

Our earthenware is set in the sawdust bed and covered with metal buckets filled part-way with straw.

Metal buckets, roasting pans and planters cover our pieces (and conduct heat).

Mary and Peter nestle a bucket on a large piece, attempting to minimize any air leakage.

“Aluminum containers act as reduction tubes. Reduction is a decrease in oxidation number.  Closing the can reduces the oxygen content after the combustible materials such as sawdust catch fire and forces the reaction to pull oxygen from the glazes and clay minerals.  Luster gets its color from deprivation of oxygen. The reaction between the oxygen and clay minerals affects the color of the clay and the metal elements of the glaze.” (Wikipedia)

I help “burp” the pieces by lifting buckets and lids, while Peter adds more sawdust.

Peter tosses sawdust on the ware where more crackling is desired. Pieces are quickly and carefully re-covered. Buckets are nestled into beds to reduce escape of air/ smoking.

 

 

 

 

 

 

 

 

Tossing sawdust on a burning-hot pot.

Whoosh! The sawdust bursts into flames.

 

 

 

 

Dramatic flames and experienced hands.

Judy’s sculpture was re-covered and left to cool a bit more before it was handled again.  Notice the crackling of the glaze.

What happens next?