Insulating Blanket Coating

The kiln now has a coat of Kaowool, a spun clay material that has an insulating quality and can withstand temperatures in excess of 2000 degrees F.  This material is similar to the tiles that cover the surface of the Space Shuttle and keep it from burning up during re-entry into Earth's atmosphere.  You can see from the photo that on the kiln it is held in place with wire which will also act a surface to grip and hold a coat of A.P. Green refractory stucco insulation that will cover the outside of the arch and further help to retain heat in the kiln during firings.   

Finishing the Chimney

The chimney is done at last.  You can see by this photo that the structure rises 14 feet above the level of the kiln floor and required using my neighbor Dave's scaffolding to put the upper parts of the stack in place.  Cody and I came up with the brick detailing at the top for a little fun at the end of a challenging part of the kiln's building process.  We also finished attaching the last elements of the roof in place and made flashing for the space between the roof and the chimney.  The damper is enclosed in the stack(where the chimney corbels in to a smaller diameter) and will help control the amount of draft the kiln will draw during a firing.

Arch Brick in Place

          These photos show the arch brick set in place and ready for the keystone to be cast.  The keystone ties the arch together and creates downward pressure on the arch brick "setting" the arch.  You can see my son Cody casting the keystone using 3000 degree F castable refractory.  Also included is a photo inside the arch form that holds the brick in place.  Once the keystone material solidifies then the arch form is removed revealing the inside of the arch.  After this the kiln's back wall and chimney will be built.

Working on the Arch

Work on laying the arch Brick has begun and, suddenly, a snow!  My black lab Bewley was helping and she enjoyed the evening working on the kiln very much.  This is slow, steady and painstaking work. 

Arch Form in Place

The arch form is now in place and ready to receive bricks to make the chamber of the kiln.  This is a catenary arch--approximately as wide as it is tall but not a round arch form like a roman or barrel arch.  If you take a piece of string and let it drape loose it will create a catenary arch..  This arch is almost 12 feet long and three feet tall.  The form is made from a skeleton of 2" X 4"s and 3/4" front and back plywood shapes with 1/8" Masonite streached across the form and screwed into place.  Look for the bricks to define the arch next.

Ready for the Arch

The walls that support the arch form are in place and ready to accept the wooden arch form that the bricks will be laid upon.  All is as level as I can get it and yet I find little places that vex me.  Such is the world of the brickmason.  I am trying to imagine the interior of this space filled with fire and pots glowing at a temperature of around 23oo degrees F...  Soon! 

The kiln floor is now established and the first layer of the side walls is in place.  These walls will be four bricks high before the arch begins.  I have an interesting collection of fire bricks new and used so it becomes an puzzle solvers task to find enough bricks for a course that are the same size.