
PLAYING WITH
TEMPERATURES
Temperature - heat and cold - changes the actual
physical properties of things, and is easy to use to help us make or
repair things, or even make our own tools.
A
very useful railroad
spike!
Making steel tools for various specific purposes has long been
done by the person who wants and needs the tool. Again, using
temperatures properly can make a hard job much easier. Leaf spring or
file steel has incredible quality, and can be worked rather easily if
first softened by a process called annealing. Place the steel to
be annealed into a fireplace or wood stove, heat it to a cherry red,
then let it cool naturally, and it will be annealed.
The annealed steel can then be cut, drilled, and shaped as
desired. While still soft it is then sanded and filed to very near the
final finish, including buffing if desired, then heated again to a
cherry red and then immediately quenched completely in oil, a process
called tempering. The oil-bath tempering restores a spring-steel quality
of temper. Then the oil scale is removed, final buffing done, the finish
edge applied (as in a knife), and the tool is ready for use. Cold water
quenching makes steel harder, but brittle.
The size of the tool desired is used as a gauge for what size
steel to use to make it. Wood rasps make fine knives or scrapers,
needing only to be swaged into shape when annealed. Swaging is
cold-forming of steel with a hammer and anvil. The combination of
annealing, swaging, and tempering can be used to fix bent leaf springs
used in many applications.
Let us assume you have a collapsed "V" shaped spring in one of your
tools. First the spring is annealed, then it is gently swaged to its
original shape, then tempered, and it is almost as good as new. Pioneer
gunsmiths restored leaf springs over campfires in the wilderness.

Heating steel makes it expand slightly, while
rapid cooling makes it shrink, or contract, slightly. Using those
principles the pioneers could put a steel rim onto a wooden wagon tire
in the middle of nowhere. The rim was formed to be slightly smaller in
diameter than the wheel, then heated in a campfire to a red color,
quickly placed around the wooden rim, then shrunk to a tight fit by
splashing the hot steel with cold water. The steel would be brittle from
the cold water quench, so better wagon smiths quenched with oil of some
kind, even lard or fat.
That same principle can be used to attach bands of steel around shafts,
for example to attach a pulley or a sleeve to strengthen a bent rod or
shaft. The sleeve or pulley is boiled while the shaft is frozen, thus
expanding the sleeve and contracting the shaft. If the sleeve was
drilled slightly smaller than the shaft, it will now fit over it, and as
the temperatures equalize the band or sleeve becomes tightly bound to
the shaft.
Primitive welding can be done with the process of hot swaging.
Say you want to make a steel band to reinforce a tank. The band is first
annealed, then swaged round to the final diameter when cold. Then the
overlapping ends of the band are heated cherry red and hammered together
on an anvil while hot. The process may have to be. repeated several
times, but the ends of the band will become "welded" together and stay
firmly attached. A gasoline or propane torch can be used for "spot"
heating for this purpose, thus confining the heat to a specific spot. If
a fire is used instead, tongs or vice grips must be used to hold the
steel while swaging, as the heat cannot be localized as with a torch.

Working with wax making candles or as a beekeeper? A
tea kettle can be your best friend. Take wax, for example. It melts at
145°F, so boiling water (212°F) can melt it easily. A brief dip in
hot water loosens a candle from a mold, and soaking in boiling water
will clean the mold. Have a candle gang mold and the candles are stuck?
Freeze the mold, and the wax and mold will contract. Thawing
expands the mold faster than the wax, and the candles should come out
easily. If not, a little boiling water from a whistling tea kettle
over the mold will expand the mold and the candles will come out easily.
Then pour boiling water into the mold to dissolve whatever was causing
the candles to stick. See more in
Making
Candles.