Chelmsford Amateur Radio Society Intermediate Course 10 Soldering

1
Chelmsford Amateur Radio Society Intermediate
Course(10) Soldering
2
Soldering

• 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
Soldering Procedure

• 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.
• Ensure Soldering Iron tips are tinned or wetted
  just beforehandto help transfer the heat

4
Solders
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 temperaturesand greater care is needed
5
Solder Types

• 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

6
Multicore Solder
7
Solder Joints
BAD JOINTTOO MUCH SOLDER
BAD JOINTTOO LITTLE SOLDER
GOOD JOINT OUTLINE OF WIRE SHOWING THROUGH SOLDER
8
Soldering Safety

• 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.