Skutt FireBox8x6 LT - Manual (Page 14)

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Overview
Ramp and Hold is a programming mode that allows you to write your own firing programs. It is used when you
are firing something that requires programs different from the factory programs found in ConeFire, Glass Fire
or PMC Programming Modes.
Whenever possible we suggest you use the built in firing modes but if you want to do something different like
growing Crystals in a ceramic glaze, casting thick pieces of glass, or tempering custom made tools, you will
need to use Ramp and Hold Mode.
Before you get started it is a good idea to know a little about firing pro-
grams. A firing program consists of a series of one or more segments that
are strung together to form the program. A segment consists of a Firing
rate (expressed in degrees per hour), a temperature that you are trying to
reach at that rate, and an amount of time you want to hold at that tem-
perature.
A program can be as simple as telling the kiln to fire as fast it can to a
specific temperature and then turn off. Most items you fire in a kiln how-
ever require you to speed up, slow down, or hold during critical parts of
the firing. You can find recommended programs for firing in books, on
manufacturers websites, on blogs, from a class...they are every where. You may find two programs that look
completely different but accomplish the same results. The key is testing. Just with recipes, some programs are
better than others.
Another thing you need to consider when trying out a Ramp/Hold program is that kilns can fire different. A
large kiln with a very large load of shelves and ware may cool slower than a small kiln. In order to get the
same results, you may need to program a cooling segment that slows down the cooling of the kiln. Again
testing is the key. It is impossible to fit everything you need to know about firing in this manual, so we highly
recommend you contact your local distributor and find out where you can take classes to advance your knowl-
edge.
Below is an example of a program written for firing a specific crystal glaze recipe like
the one in the picture. It is a 5 segment program with varying rates and hold times. With
Crystal glazes it is important to hold at specific temperatures on the cooling side of the
program. You can see that between segment 3 and 4 that the temperature drops 210
°F (117 °C) to 2000 °F (1093 °C) and then holds at that temperature for 1 hour and
then drops another 100 °F (55 °C) and holds for 3 hours. When the last segment in the
program is complete the kiln shuts off and cools to room temperature.
SEGMENTS 1 2 3 4 5
RATE 350°F/HR 750°F/HR 150°F/HR 750°F/HR 750°F/HR
TEMPERATURE 700°F 2000°F 2210°F 2000°F 1900°F
HOLD 00.00 00.00 00.10 01.00 03.00
Sample Ceramic Crystal Glaze Program