METAL BODY REPAIR - OD1653 - LESSON 2/TASK 2
The most common material used as a soft solder bond is an alloy composed of
50 percent tin and 50 percent lead.
There are two types of solder
manufactured for the repair of vehicle radiators. These types are acid core
and wire solder.
All solder is removed from the parts prior to assembly. Any area that shows
signs of not being tinned must be retinned. If the oxyacetylene torch is
used, the flame is adjusted to a carburizing flame. If the soldering iron
is used, the copper point must be properly heated and tinned. If the copper
point is too cold, the solder will not flow freely and will not stick to the
metal. If the copper point is too hot, the solder will form little globules
that will run off the surface of the metal.
A small amount of solder
properly flowing into the joint will give a much better result then a joint
that has solder piled up in a rough seam.
A good soldering job is
recognized by the manner in which it flows into the joint. A rough, lumpy
seam indicates a poor job. A seam or joint of this kind should be gone over
with a properly heated iron to flow down the ridge and to pick up the excess
solder. The speed with which soldering can be done with a torch flame is an
advantage. It is preferred over the soldering iron for most purposes. The
method of applying solder with the torch is similar to the method used with
the soldering iron.
With the torch, solder is melted and flows directly
upon the surface of the metal. The heat of the metal and the torch flame
are both essential to liquefy the solder.
Satisfactory requirements of a
torch flame are:
(1) Will not be extinguished by the fumes of the flux or acid.
(2) Gives sufficient heat to accomplish quick fusion of the solder, and
yet not hot enough to damage the metal being soldered.
(3) Adjusted to suit the job to include a long, slim, needle-like flame
capable of reaching difficult places, as well as a heavy, bushy type flame
for dismantling parts.
Various gases can be used for soldering with satisfactory results. Hydrogen
gas, supported by compressed air, produces a flame that is very
satisfactory. This gas may not always be available. Acetylene gas is also
used, but is not