Firing PMC+ and PMC3
Silver Clay
The PMC pieces should be completely dried. This can be dried in the open
air or dried with a heat source such as a hair dryer, heating tray or
similar device. To verify that a piece is completely dry, place it on a
shiny metal surface such as a piece of aluminum foil or the inside of the
lid from a candy tin. Leave the piece on the metal for several seconds and
then remove it. Look on the metal for a “ghost”, a water vapor mark
which is present if the piece is not completely dry.
A second method is to hold the piece
against your cheek. The skin on your face is sensitive to temperature. If
the piece is not completely dry, it will feel cool against your cheek.
When the piece is completely dry, fire it
according to the applicable table.
PMC+ and PMC3
consists of fine silver particles suspended in an organic binder with
water. When fired in a kiln or with a torch, the binder burns off, leaving
a 0.999 fine silver piece. The PMC+ sheet contains no water and feels like
a sheet of vinyl. It has a long shelf life and is highly resistant to
drying. In both instances, shrinkage is about 10%.
|
PMC+
Silver |
| Temperature |
Hold
Time |
| 1650°
F (900° C) |
10
minutes |
| 1560°
F (850°C) |
20
minutes |
| 1470°
F (800° C) |
30
minutes |
|
|
|
PMC3
Silver |
| Temperature |
Hold
Time |
| 1290°
F (700° C) |
10
minutes |
| 1200°
F (650° C) |
20
minutes |
| 1110°
F (600° C) |
45
minutes |
|
PMC & Other
Materials
PMC+ and PMC3, work well with a wide range of other materials. Of
particular interest is use of glass and ceramic materials with PMC+ and
PMC3. When using these materials in combination, always remember to use
the firing schedule which applies to the most sensitive material being
used.
Thus, if using PMC+ with glass, the glass
is the more sensitive material. Therefore, we recommend that the firing
use a slow ramp (increase in kiln temperature) of about 1500° F per hour
to the lower PMC+ temperature (1470°F) for 30 minutes. This temperature
will result is a complete fusing of the glass into a rounded cabochon.
If it is desirable to retain surface
dimension to the glass, we recommend the use of PMC3 and the higher PMC3
firing schedule (1290°F for 10 minutes). Even here, however, is it
appropriate to use a slow ramp (increase in kiln temperature) of 1500°F
per hour.
As always when firing glass, remember to
guard against devitrification and thermal shock. We recommend a crash cool
(rapid decrease in kiln temperature) from the hold temperature to 1000°F,
then a natural slow cooling period to room temperature.
One of the wonderful aspects of PMC+ and
PMC3 is the low level of waste. Both products, can be reconstituted by the
introduction of small amounts water if they become dried. Even after
firing, you can place additional clay, in any of the four forms, onto a
piece which requires additional work and re-fire the altered piece. You
can repeat this process many times with no adverse effects on the piece.
The materials are very forgiving and allow the user a great deal of
flexibility in completing the final design.
|
