2. The accepted definition of soldering is:-
• The joining of metals using a filler material of a
lower melting point than that of the parent metals
to be joined.
Note that some metals are easier to solder than others:-
• Tin, Copper and Brass are far easier to solder
than Steel or Aluminium

3. • The secret of a good solder joint is clean, clean and clean again.
• A solder joint is produced by:-
1) First thoroughly cleaning both surfaces to be joined.
2) Tin both surfaces.
3) Mechanical fix the components together.
4) Then apply heat to the joint and bring the solder to the joint.

4. Method Of Soldering:-
 Two pieces of metal to be soldered together must be filed or scraped
to a clean metallic surface if not already bright.
 They are brought into the position in which they are to be soldered
and firmly held together.
 The joint is sprinkled or swabbed with flux to remove grease and
prevent the formation of oxide.
 Holding a bar of solder in one hand and a heated soldering copper in
the other, the operator brings the copper against the bar, melting a
slight amount of solder which either drips on the joint or sticks to the
point of the copper by which it is wiped and spread over the joint.
 The two parts to be joined must be heated by the copper to the fusion
point of the solder in order to make the molten solder stick to them.
 A stronger joint may be made by first carefully tinning the surfaces
joined in soldering.

5. Traditional Solder is an amalgam of Tin and Lead. The percentage
of each of these materials defines the use for the solder
%Tin %Lead Use
60 40 Good for all electrical and mechanical work
45 55 Very liquid used in plumbing
50 32 Low melt solder for white-metal casings
Plumbers solder is not suitable for electrical work
Modern Lead Free solders need higher temperatures
and greater care is needed

6. Solder comes in many forms:-
• A solder stick with separate flux
• Solder Pastes good for joints outside, easy to use
• Multi-core solder is the usual form for electrical work
• Flux is present in many solders to remove surface
Oxide layers and assist solder flow

7. Flux is a chemical compound that is applied and shields the
joint surface from air and prevents oxide formation.
Although flux will dissolve and absorb oxides, the metals
that are being joined should be properly cleaned prior to
brazing.

8. Soldering is use in plumbing in electronics and in jewelry
metalwork.
Jewelry components, machine tools and some refrigeration and
plumbing components are often assembled and repaired by the
higher temperature silver soldering process
It can also be used as a semi-permanent patch for a leak in a
container or cooking vessel.
Electronic soldering connects electrical wiring and electronic
components to printed circuit boards (PCBs)

9. Remember:-
 Use soldering-iron stands to prevent accidental contact
with the hot bit of the iron when not in use.
 Soldering work benches must be well ventilated to avoid
inhalation of solder fumes.
 Always use eye protection when soldering to prevent
solder or boiling flux from splashing into the eyes.

10.  Low power is required;
 Low process temperature;
 No thermal distortions and residual stresses in the joint
parts;
 Microstructure is not affected by heat;
 Easily automated process;
 Dissimilar materials may be joined;
 High variety of materials may be joined;
 Thin wall parts may be joined;
 Moderate skill of the operator is required.

11.  Careful removal of the flux residuals is required in
order to prevent corrosion;
 Large sections cannot be joined;
 Fluxes may contain toxic components;
 Soldering joints can not be used in high temperature
applications;
 Low strength of joints.

12.  The basic difference between soldering and brazing is the
temperature necessary to melt the filler metal. That
temperature is defined to be 842ºF/450ºC by the American
Welding Society (AWS) but is often rounded to 840ºF. If the
filler metal melts below 840ºF the process being
performed is soldering. Above that temperature, the
process is brazing.

13.  Welding uses steel rod, which is melted into the joints
or voids. Strongest of the three.
 Soldering is similar, except a low temperature melting
point lead//tin alloy is used. Weakest of the three. Also
there is silver solder, somewhat stronger.
 Brazing is similar to soldering, except higher melting
point material is used, and it's stronger than soldering,
but not as strong as welding.


14.  Unlike welding, brazing only has minimal impact on
material properties. Braze alloys can also be expensive.
Copper alloys are commonly brazed, particularly since
copper's properties make it very difficult to weld.
 Soldering uses an alloy that is liquid at relatively low
temperatures to join two other metals. It has the least
impact on the base materials, and also provides the
weakest joint. It is particularly useful when heat can
damage or distort the materials being joined. Electrical
components are commonly soldered to avoid heat
damage. Various metals can be soldered together, such as
gold and sterling silver in jewelry, brass in watches and
clocks, copper in water pipes, or iron in leaded glass
stained window.