Sunday, February 26, 2006

Raku In Wisconsin

Raku in Wisconsin
Early February
Well below Zero
All for a dozen test tiles
Crazy Huh?

Raku Burner System

It doesn't look like much, but this is my Raku Burner system. It is called a "Big Bertha," model #166. It is made by L.B. White Co. Inc. in Onalaska, WI. Cost is approximately 80 dollars new. I borrowed this one from a friend of mine, but a good source for burners is eBay, under "weed burners." Real Cheap on eBay.
The burner consists of a torch head, an orifice, a handle or shaft, a manual valve, a hose and a regulator.
Thanks to LB White for the specifications and part numbers.

Model: 166 (Big Bertha)
Heat Output: 500,000 BTUH
Operating Fuel Pressure: 25PSIG
Hose: 550-20703 1/4 inch OD x 10 feet
Regulator: 550-21788 25PSI
Operating Pressure/Fuel 25 PSIG LP Vapor

Many thanks to Frank Colson who informed me that building a kiln without a burner system really is "Kiln Building For Dummies."

Tuesday, February 07, 2006

Tea Bowl Close Up

Nice Crackle Pattern.

Clear Crackle Glaze

70% Gerstley Borate

30% Neph. Sy.

Second Firing

Second Firing and I'm a "Happy Camper." I fired these with the help of my Friend John Roesler. Firing time was approximately 1/2 hour using a 20lb tank of propane. It was sunny and about 25 degrees out. Had no propblem with the tank freezing up. Oh! Thanks to Carol for the photos.

Sunday, February 05, 2006

First Firing

I had to fire my kiln immediately after completion. It was 24 degrees and pretty windy. In fact it was just cold and windy. The plastic garbage can helped to serve as a wind break. The sawdust filled reduction can and the lid served the same purpose. The sledge hammer was placed on top of the kiln shelf pieces to hold the burner in place.

In 25 minutes I was pulling glowing red tea bowls from the kiln and placing them in the reduction can.

The Finished Raku Kiln

To finish the kiln just cut out the fiber from the flue and the burner port. I used the utility knife and cut from the outside in, leaving about an 1/8 of an inch edged between the fiber and the metal.

If you have all the materials gathered together before you start, I think most people can build the kiln in about 3 hours.

I was firing immediately after completion.

Step 6--Attaching the Buttons

I thought this step was the only difficult part of the project. I drilled two small holes into the can for each button. It was threading the wire through the holes that was difficult. Once threaded I just twisted the wire tight with a pair of small pliers.
For the lid I threaded the wire from the outside of the lid, through the holes and through the fiber. I then just pierced the fiber button through the wires and twisted tight with the pliers. I trimmed the long ends with a pair of wire cutters. This was a lot easier than threading from the inside out.

Step 5--The Buttons

I scrounged a piece of fiber board from a friend of mine who worked for a furnace/AC repair place. Using a utility knife I cut out about 20 squares that measured 1-1/2 by 1-1/2 inches. The board was 1-inch thick.

I used High Temp. Wire, 8 inches long for each button. The wire I used was the thicker gauge wire made by Kemper. I think it was about 5 dollars for 10 feet of it. I bought 3 packages and only used one for this project.

Anyway, kind of bend the wire in half and gently poke the two ends through the fiber square. It goes through really easy. I actually only used 8 buttons for my entire kiln but might have to add more later. I used four for the kiln lid and four for the interior of the kiln. This seemed to work just fine for my first firing.

Step 4--The Kiln Lid

Using the marker, trace around the edge of the garbage can lid and cut out with the utillity knife. Turn the lid upside down and carefully tuck the fiber round into the bottom side of the lid

The fiber will be held in place by either handmade ceramic buttons with High Temperature kiln wire or by buttons cut out of insulating fiber board. I choose the fiber board because I had heard that the ceramic buttons tend to break after repeated firings.

A picture of my fiber buttons will be posted in the next step.

Step 3--The Kiln Bottom

This is the easiest part of building the fiber lined garbage can raku kiln. Place the can on the fiber and trace around the perimeter with a magic marker. I set the can on the edge of the end of the roll and the side. This allowed me to save about a 4 inch by 4 foot pieces of fiber for future use in some other project. "Waste not, Want not."

Cut two rounds pieces out for the bottom of the kiln. This makes it possible to use a single piece of fiber for the main interior part of the kiln. Once the pieces are cut, gently place each round in the bottom of the can, one piece on top of the other.