Drop Ring Mold
This is part two of
a multi-part tip on making a drop ring mold. Click here to
go to part one.
Once the hole has been cut in your
material, the next step is to prepare the mold for firing.
Preparing the Mold for Firing
For many products, this involves
pre-firing the material to at least 1300F/700C in order to drive
off binders. This can be done prior to cutting, but since some
products become softer after pre-firing itís a good idea to cut
first, fire second. After pre-firing, apply a coating of kiln
wash to the surface of your material to help prevent sticking.
Make certain you take care to kiln wash the inside of the hole
as well as the top layer of the mold.
Once the kiln wash dries youíre ready to
fire. Any standard drop ring schedule, such as those detailed
here, can be adapted to work for your
custom mold. When adapting, keep in mind that drops through
larger holes will take place at lower temperatures than through
small ones. Also, as with all drop ring firings, it is critical
to closely monitor the glass as it drops through the ring to
ensure that it doesnít over or under fire.
Future tips will cover
more drop ring techniques, such as making bowls, making rimless
items like vases, and making bowls with pedestals.
Copyright 2006 Brad Walker. All rights
Parts of this discussion
have been previously published in Glass Craftsman