colors in a fire
Gary Rayson (garayson@NMSU.EDU)
Wed, 3 Jul 1996 13:09:26 -0600
Greetings from the "sunny" southwest.
I have just read, with considerable interest, some discussion regarding
adding metal salts to a fire to produce "unusual" colors (red, blue, green,
etc.). An earlier reply provided an excellent "layman's" explaination of
the source of the colors. Because I happen to spend a great amount of time
in my "other life" (i.e., outside of scouting, a.k.a. work), I thought I
might be able to shed some more light <big grin> on the subject.
First a word about the use of chemicals of any kind. All chemicals can be
either beneficial or dangerous depending on how they are used and how much
us used. They should _all_ be treated with the respect they "demand". (Yes
even water has an LD-50 toxic limit.) When ever non-food chemicals are
used, it is always wise to keep them away from food preparation or serving
areas. If that is not possible, be certain to wipe down the surface with a
damp paper towel (if corrosives are used, follow the safety precautions
included with the product). Avoid direct contact with skin, eyes, etc. if
possible. This is not meant to be a comprehensive discussion of chemical
safety but only a general indication of some "common sense" practices. When
in doubt, read the warnings or call the appropriate "authorities".
Now back to the issue of making colored fire. Many of the materials used in
pyrotechnics to produce the brilliant colors will work in a campfire. A
source might be a fireworks manufacturer (sic) both in terms of selection
and availability. Another source of some of the more "exotic" metal salts
might be the local high school chemistry lab (you won't need very much to
produce the desired effect).
A few possibilities are:
lithium salts for a deep red
strontium salts for a crimson
calcium salts for a red
barium for a deep green
lanthanum for a definite purple (much better than potassium)
most of the "rare earth" elements, as soluable salts, will produce various
A possible side excercise, once you have selected and acquired the "colors"
you want, is to dip into the metal salt solution a small piece of wire with
a small loop in one end and the other end in some sort of thermal insulator,
such a being sealed in a piece of glass tubing (another item that should be
available from the high school lab). Placing the metal-wire loop into the
flame of a propane torch (the hardware store variety) will yield the
appropriate colored flame. This will allow the boys (or who ever) to
experiment with different metal solutions and combinations before producing
the "final product".
I hope this helps.
Associate Professor of Chemistry
New Mexico State University
Box 30001, Dept.3C
Las Cruces, NM 88003
Terry Howerton Sakima Group, Inc. SCOUTER Magazine Kansas City