|
Bristol Studio
Gas Car
Kiln Construction
2008 |
The kiln below replaced a gas car kiln that
Robert used from 1976 until 2007. |
Gas Kiln Construction
 |
 |
| |
Robert hangs a plumb line to determine location of
the chimney. |
Gas Kiln Construction
Gas Kiln Construction
Gas Kiln Construction
 |
 |
Bricks on the edge of the cart were notched
in order to fit into the keyway on the side walls and not "drag". |
The Cart was designed to accommodate 9" bricks.
Three layers of insulating fire bricks were used on the floor. |
Gas Kiln Construction
|
 |
|
|
View of side wall, leading back to chimney area,
during construction.
Note: Cart frame before bricks are added. |
|
 |
 |
Bricks were layered to create a "taper" on the cart,
with a mirror image on the adjacent wall. |
There is a "one inch taper" from the front of the cart to
the rear, this eliminates the possibility of bricks catching on the
walls, as the cart moves into and out of the kiln chamber. |
 |
 |
| |
The notched bricks are clearly visible in this photo,
by removing an quarter inch of material, the cart can move in and out
freely. |
 |
 |
| Walls were built three courses deep, this
gives added insulation, but more importantly it allows the bricks to
interlock in such a way that there are no unbroken joints from the hot
interior to the outside wall. |
There are two exit flues, allowing for both to be
open if more draft is needed, but will usually be fired with just the lower
flue open. |
 |
 |
| The kiln was laid "Dry" with no mortar, except in a
few areas that needed to be leveled. IFB (insulated fire brick) bricks are so true to size, that
mortar actually impends a good fit. |
Robert continually checked the kiln walls to make
sure they were "level". |
 |
 |
| |
The kiln's damper is shown above. |
 |
 |
| The kiln's damper, above. |
Burner flues on either side of the chimney. |
 |
|
| The kiln's damper. |
|
 |
 |
| A wooden arch form is shimmed 1/2 higher
than the support it rests upon. This allows the form to be dropped when
all the arch bricks are in place. |
The arch on this kiln is a modified Cantenary Arch,
it has a one to two ration of height to width. While sprung arches are
more typical on IFB gas kilns, Robert chose this arch for artistic
reasons. |
 |
 |
The arch is composed of 4.5 inches arch
bricks.
A row of Hard-brick Arches were placed on either end to neaten the look
and provide caps for the fiber blanket and cement cap. |
A skewback was cut to fit the size necessary
for this
row of arch bricks. |
 |
 |
| |
A layer of fiber blanket covers the arch. |
 |
 |
A layer of Mineral Block is layered over the fiber
blanket.
The Mineral Block is cheaper than fiber blanket and
is firm, to better
withstand the weight of the cement cap. |
Finally another layer of fiber blanket is placed over
the Mineral Block
and block wire is fitted over the entire arch. |
 |
 |
Block wire is fitted over the entire arch,
this acts like re-rod for the concrete mix. |
Robert uses ordinary concrete mix. |
 |
 |
| Mixed with water to the proportions
suggested on the bag, but he adds 25% mortar mix to make a smoother
finished surface. |
Mixing was done quickly with just a hoe and wheel
barrel. |
 |
 |
A total of 480 lbs of mortar & concrete mixed were
used
to coat the roof of this kiln. |
The mixture was slightly stiffer than ordinary
batches
in order to hold onto the steep sides of the arch. |
 |
 |
| The concrete cap varied from one to one
and and half inches in thickness. |
|
 |
 |
| The entire process of capping the kiln
with concrete took about 3 hours. |
Floating the trowel once the set had begun,
left a smooth clean finished surface. |
 |
 |
| Robert likes to cap his kilns with this
hard shell to protect the fiber blanket, and to "load" the arch, the
added weight on the arch increases its stability. |
The last bricks are laid on the cart, and since there
are three layers of brick it does not require the metal bracing that is
commonly used on thinner doors. |
 |
 |
| The kiln is fired using propane gas. |
There are two Ransom B-4 Burners on either side of
the chimney. |
 |
 |
| A floor flange was welded to the front of
the cart. Standard 1/2 pipe fitting were used to create a handle
to pull or push the cart. |
The wheels of the cart are 6" V-groove, and run on
inverted angle iron that is used for track. |
02/07/09
|
