METAL BODY REPAIR - OD1653 - LESSON 2/TASK 2
This lighter construction has generally replaced the cast metal type in
passenger cars and lightduty trucks, where it is usually concealed by the
hood and radiator grill.
(1) Water Tanks. Almost all radiator tanks are cast or stamped in one
piece to reduce the number of potential leaks. A baffle plate in the upper
tank, below the neck, eliminates excessive splashing and distributes the
water uniformly over the tank.
(2) Radiator Fittings. The radiator fittings are the filler neck and
inlet connection of the upper tank and the outlet connection and drain valve
of the lower tank. These are made of malleable iron or pressed metal. When
they are manufactured as separate parts, they are brazed, soldered, bolted,
or riveted to the tanks.
(3) Tubular Core. This type is made of many vertical tubes (drawn or
seam welded) soldered through thin sheets of metal at the top and bottom
(called header plates). The header plates form mounting pads for the upper
and lower tanks and block passage of water from the tanks to the core except
through the tubes. The tubes are generally spaced about 3/4 inches apart,
in two to four straight or staggered rows approximately 1/2 inch apart
(figure 35 on the following page). In a staggered row, twice as many tube
rows are exposed to the air entering the radiator, which increases the
cooling capacity. Round tubes are easily broken by the expansion of
freezing water, whereas oval tubes will be distorted to some extent before
breaking. The radiating surfaces of these tubes are occasionally increased
by spiral fins on each tube or, much more commonly, by thin sheets of metal
(horizontal fins) extending all the way across the radiator, 1/8 inch to
3/16 inch apart, in contact with each tube. The front edges of the
horizontal fins are usually crimped or bent back to a double thickness which
strengthens the radiator core. In most radiator cores, the fins are
soldered to the tubes to speed the heat transfer. A tubular core radiator
is generally larger than a honeycomb core radiator with the same cooling
capacity.
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