Lesson 5: Soldering


Soldering is a process which joins two or more metal items by melting and flowing a filler metal, the solder, into the joint. The filler metal having a lower melting point than the adjoining metal.

Soldering is not the same as welding. Welding involves melting of the work pieces.


Solder is a fusible metal alloy that is                                                                       .
The fusible metal alloy has a lower melting point temperature than the work pieces.

A soldering iron is the tool used to heat and melt the solder onto the work pieces.


Video Tutorial com Adafruit.com (Collin’s Lab)

Common Soldering Issues

Cold solder joint:

  • Solder has not fully fused to the surface causing unreliable electrical connections.
  • Common causes:

Oxidation can be seen as dark spots:


Temperature settings for solder

Lead-based solder: 650 degrees F

Lead-free solder: 750 degrees F

Lead-based solder is easier to use, but lead-free solder is more commonly found.

Flat Screw Driver tips: Best for through-hole parts

Flat screw driver tip for through-hole parts

Flat screw driver tip for through-hole parts

Fine point tips: Surface mount components

Fine point tip for surface mount parts.

Thick hoof tip with a wide contact area: Large joints

Thick hoof tip for large joints

Soldering tools and accessories

  • Soldering iron
  • Soldering stand
  • Brass mesh or damp sponge for tip cleaning
  • Tip cleaner / conditioner
  • Solder sucker
  • Solder wick
  • Fume extractor to remove smoke
  • Helping hand or third hand
  • Vise grips

VE-STANDLC $_35 B000B61D22.01.lg e56e99f859ddb0573c6fa67faa394bfd s-l1000 Solder_Wick Solomon_Solder_Sucker