1935 Cadillac - GM Heritage Center

CHAPTER IV
COLD WEATHER OPERATION
SATISFACTORY operation of the car in freezing temperatures
depends upon having the car prepared for cold weather and
in giving it the special attentions which are required under such
conditions. All the information relating to the care and operation
of the car during cold weather has been grouped in this chapter
to assist the operator in maintaining the fine performance of the
car throughout the winter as well as the summer. This chapter
should be reviewed just before the beginning of the winter season
so that full benefit may be had of all the suggestions it contains.
Preparing for Cold Weather
Anti-Freezing Solutions
In selecting anti-freezing solutions for winter operation the
local conditions and the type of service must be considered. The
following information is given to enable the individual owner to
more intelligently select the anti-freezing solution best suited to
meet his own conditions.
The available commercial materials for preparing anti-freezing
solutions for automobile radiators are denatured alcohol, methanol
(synthetic wood alcohol), distilled glycerine, and ethylene
glycol.
Alcohol and Methanol
Denatured alcohol and methanol solutions have been the
most generally used anti-freezing solutions. Denatured alcohol
and methanol arc widely distributed, afford protection against
freezing, and are not injurious to the materials used in the cooling
system.
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There are two principal objections to denatured alcohol and
methanol. These materials are lost by evaporation, especially on
heavy runs, and unless the solution in the radiator is tested
periodically and sufficient anti-freeze added to replace the loss by
evaporation, the engine or radiator, or both, are likely to be
damaged by freezing. The car finish is damaged by contact with
denatured alcohol or methanol solutions or vapors, and any
material accidentally spilled on the finish should be flushed off
immediately with a large quantity of water.
Methanol for anti-freeze purposes is sold in the United States
in the correct concentration to give the same protection against
freezing as denatured alcohol. The table below may be used for
both denatured alcohol and methanol.
Lowest
Temperature
Expected
10 F.
Per cent
by
Volume
30
Specific Grav
(at 60" F.)
Denatured Alcohol
Methanol
.972
.9668
OF. 38 • 9567 .964
—10 F. 45 .9475 .957
—20 F. 51 .9350 .950
—30 F. 57 .9260 .944
Important: The special inhibitor used in the cooling system
(see page 44) affects the hydrometer readings of the solution and
allowances must be made for the difference. With the inhibitor in
the cooling system, the actual freezing temperature of an alcohol
or methanol solution is five degrees higher than indicated by the
hydrometer. In other words, if the hydrometer reading indicates
protection down to zero, the actual protection would be only
down to five degrees above zero and similarly throughout the
scale.
Glycerine and Ethylene Glycol
Distilled glycerine and ethylene glycol solutions are, in first
cost, more expensive than alcohol but, as they are not lost by
evaporation, only water need be added to replace evaporation
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