The Top Loading Kiln
This is one of a continuing series on choosing a glass kiln for fusing and slumping.
Click here to go to the first part of the series.
The top loading kiln is usually a multi-sided box with a lid that
swings open like the lid of a phonograph record player. When
open, the kiln allows easy access to the inside. Since most
top loading kilns are made from kiln bricks that have been shaped to
fit together, they tend to be a bit less expensive than
comparatively sized front loading kilns.
Things to evaluate when considering the purchase of a top
loading kiln include:
1. Shape
Most top loading kilns are multi-sided. Eight sides are
most common, but it is not unusual to find top loading kilns with
any number of sides (from as low as six to a dozen or more).
One side effect of this shape is that while it will work well with
round items (such as bowls) it tends to be a bit inefficient for
square or rectangular items.
2. Element placement
Top loading glass kilns tend to have elements in both the top and
sides. A few models have top (or side) elements only. Of
these two, top elements are most critical for the glass kiln -- if
your kiln has side elements only, you will need to fire more slowly
than if you have side and top elements. Some larger top
loading kilns will also have elements in the kiln floor; this is a
good configuration for kilns that will be used for glass casting.
3. Door hardware
The lid of the top loading kiln is usually attached to the kiln
with a hinge. When comparing kilns, check out the quality of
this hinge; the better made kilns will have more substantial hinge
hardware than lesser kilns. One good feature to look for is
the ability to easily prop the lid open an inch or two if needed for
venting or cooling more quickly; some kilns have lids that can be
easily propped, while others require the use of a piece of kiln
furniture or similar refractory item. Also, be aware that with
very large top loading kilns (such as coffin-shaped kilns) the lid
can be very heavy.
4. Practicality
Because hot air escapes at the top of the kiln when the lid is
opened for combing or related activities, top loading kilns can be a
bit more difficult to use for activities that require manipulating
the glass. Also, because top loading kilns are often placed
below waist level on the floor, it can be awkward to reach inside
the kiln. Nevertheless, top loading kilns tend to be easier to use if your pieces have a lot of small
elements or
stringers that tend to move about when they're placed in the kiln.
It's much easier to see inside a top loading kiln than a front
loader.
Coming soon -- more on other kiln configurations,
including the bell kiln.
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Copyright 2005 Brad Walker.
All rights reserved.
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