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"how to" tutorial series
"How To" Tutorial Series
How to Make/Modify and Use an Alcohol Lamp
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John Gustav Delly, Scientific Advisor, College of Microscopy, Westmont, IL |
Figure 6 illustrates three alcohol lamps that
are components of chemistry sets for youngsters; similar alcohol lamps have
been supplied in such kits for over 80 years. The lamps illustrated here are
all relatively small – about one ounce capacity – but that size is totally
adequate for both these sets and for general microscopy; indeed, similar lamps
are often a part of microscope sets for youngsters. The three lamps here are
all 40-50 years old. The alcohol lamp on the left, from a Gilbert Chemistry
Outfit, is fitted with an arrangement for elementary blowpipe work; the tip is
constricted to a narrow opening, and in use a piece of rubber tubing is fitted
to the lower end, and the user blows through the other end of the tubing, keeping
the cheeks fully puffed out, inhaling through the nose in typical blowpipe
fashion, so as to maintain a steady stream of air to produce a very sharp,
intensely hot flame. The alcohol lamp in the middle, from a Gilbert Chemistry
Outfit of a different era, is typical and unremarkable. The alcohol lamp on
the right is from a Chemcraft Chemistry Outfit (Porter Chemical Company), and
has the molded-in legend “Porter Alcohol Lamp”; the wick is badly in need of
trimming! None of these lamps feature a vent hole.
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Figure 6 |
Figure 7 is a page from a Chemcraft Chemistry
Outfit manual, describing and illustrating the use of the blowpipe feature of
the alcohol lamp.
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Figure 7 |
Figure 8 is The Alcohol Lamp page from the
Skilcraft® Chemlab® Manual. The text says “Do not fill to the top of the
bottle” and “Fill the lamp bottle with alcohol only to the start of the neck or
lower”. The “Fill Line” in the illustration is, however, too high. This
manual also says “The best fuel for the alcohol lamp is any commercially
available denatured ethyl alcohol (grain alcohol), available only by
prescription …. Do not use methyl alcohol (wood alcohol) because it has
additional poisonous properties, isopropyl alcohol is readily available, but it
will burn with a sooty flame”.
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Figure 8 |
Figures 9 and 10 are pages from other
“Do-it-Yourself” sources; interestingly, the text in Figure 10 recommends
making a wick cap from a brass rifle cartridge (this reference is from a UNESCO
source).
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Figure 9 |
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Figure 10 |
It was Short (Microscopic Determination of the
Ore Minerals, M.N. Short, Geological Survey Bulletin 914, USGPO, Washington,
D.C., Second Edition, 1940) who illustrated and described the use of a narrow
brass tube and cotton string to make an alcohol lamp for microchemical methods
– See Figure 11.
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Figure 11 |
Figure 12 illustrates two British-made alcohol
lamps – both are excellent. The capacity of both lamps is about two ounces.
They are both dimensionally stable, and both employ ground-glass hoods of
different design. The lamp on the left has a loosely laid in ceramic wick
holder, and is vented by its loose fit. The lamp on the right has a
female-threaded brass fitting cemented to the glass neck, and a threaded
screw-in brass top/wick holder, which does have a vent hole drilled through!
Filled no more than about half way, this lamp is ideal for general heating
purposes. In Britain, these “spirit lamps” commonly burn “Methylated Spirit”,
often slightly tinged with Gentian Violet, as illustrated in
Figure 12.
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Figure 12 |
Figure 13 illustrates an interesting alcohol
lamp for portable or field use. It is part of a World War II Field, Needle
Sterilization Kit. It is nickel-plated brass, and fit in the bottom of a
cigarette-package-size, front-opening metal box with this burner at the bottom,
and an elongated, round-bottomed sterilization tray on top, which was just
large enough to hold one or two hypodermic needles. A quarter-ounce of alcohol
provides enough fuel for this lamp to burn for one hour. This is the alcohol
lamp I use in my Field Kit.
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Figure 13 |
I recently had the opportunity to modify a
commercially-available alcohol lamp for one of the staff members, and then two
others on the staff also requested one. I started with the purchase of an
alcohol lamp from McCrone Microscopes & Accessories; this lamp is illustrated
on the left in Figure 14. It is not a bad design – small, stable, metal
cap/wick holder and hood made of brass; the only thing it was missing for
microscopical work was a pressure-equalization vent, and a smaller wick. A
vent was made by drilling a 1/16” hole through the top of the cap. For the
smaller wick I decided to custom-make a piece of brass that would fit inside
the supplied opening, but that would itself have a much smaller opening that
would accept a fine woven-cotton string, or a fine woven glass fiber wick. The
custom-made piece is shown lying between the two lamps in Figure 14, and
installed in the lamp on the right.
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Figure 14 |
Specifically, the outside diameter of the wick
tube was 0.275”, and the inside diameter was just under 0.250”. I started by
chucking a 2” length of ¼” diameter brass rod into my Unimat, a small
hobbyist’s lathe, and turned a 5/32” length at the end down to 0.16” diameter.
This end was then center drilled, and a 3/32” hole was drilled something more
than 1” deep. The rod was then turned down to 0.24”. The other end of the rod
was then cut-off and faced so that it was 1” long, plus the 5/32” extension;
this is the piece shown lying down in Figure 14. This adapter was then epoxied
into the wick tube, and the new string wick threaded through. Figure 15 shows
a close-up of the completed modification, wick reducer and breather vent. As a
final touch for my colleagues, I embellished the shoulder of their personal
lamp with their own initials, by employing a rapidly rotating zirconium rod
chucked into a hobbyist’s motorized hand tool.
click image to enlarge (103K)
Figure 15 |
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