How Its Made: Radiators

when the gasoline in a car engine burns

up to 70% of the energy generated

converts into heat a lot of this heat

goes out the exhaust system but much of

it stays heating up the engine the cars

cooling system prevents overheating the

systems key component is the radiator a

water and antifreeze mix absorbs the

heat generated by the engine the fluid

then flows through the radiators tubes

to cool down the tubes are made from

paper-thin brass rollers bend the four

centimeter wide strip into the shape of

a flat tube the tubing then runs through

a vat of bubbling hot molten lead as the

tubing exits for that it runs through

cold water that hardens the lead coating

a cutter then chops the tubing into

pieces the length of which varies

according to the model of radiator these

are about 76 centimeters long meanwhile

another machine shapes a narrow strip of

copper just one and a half millimeters

thick into what are called cooling fins

as we'll see in slow-motion the machine

folds the copper strip fan-like then

perforates it creating mini air vents

when the hot fluid runs through the

tubes these fins will transfer the heat

to the air flowing through the radiator

the cooled fluid can then go back for

another round of absorbing engine heat

the cooling fins come out of the machine

cut to size then workers manually stack

the tubes and fins one on top of the


they straighten them out then apply a

brass tag indicating the model number

and date of production then they

compress and strap the components

together elsewhere a computer-guided

machine punches out a pattern on brass

sheets these will become what are called

headers there's one on each side of a

radiator the punching tool then changes

to a knife which now cuts along the

perforation lines

using a press they Bend each header then

punch slots for the radiators tubes

now using a mallet they hammer the

headers on to the ends of the tubes the

banging inadvertently closes a few tubes

so they use a special roller to reopen

them after cleaning the surface it's

into an oven at 315 degrees Celsius in

just two minutes the lead melts using

the tubes and cooling fins after

straightening out any crooked tubes

workers dip the headers in a tank of hot

liquid lead for 30 seconds this Sauter's

them to the sides of the radiator they

apply a few drops of lead on the corners

for reinforcement the headers and tube

openings are now encased in lead workers

now feed a sheet of brass into a press

to form the tanks that go on to the

headers one contains a brass tube hot

transmission oil enters one end of it

and exits the other cooling along the


once workers finish welding the tanks to

the headers they solder on what's called

the filler neck a spout for pouring

antifreeze into the tank on the opposite

tank they weld on a water intake pipe

this will be the entry point for the

fluid heated by the engine

finally they coat the finish radiator in

an asphalt based black paint the asphalt

content makes the paint heat-resistant

and protects the radiators cooling fins