*Health Hazards

  • Soldering involves contact with lead. Please wash your hands after handling leaded solder. Avoid eating or drinking.
  • Soldering produces fumes that can be harmful if inhaled in large quantities. Use fume extractors or work in a well-ventilated area.
  • The soldering iron tip is extremely hot (up to 400°C). Be cautious to avoid burns. Always place the soldering iron in its stand when not in use.
Good Bad Fix
Clean tip regularly with tin tip, damp sponge, or brass sponge

Shiny, clean, and smooth
Dull, gray, frosty, cold joints		 Add flux, reheat, maybe some solder

Concave fillets (cone-shaped)
Irregular-shaped joints		 Reheat, add flux
100% coverage of the joint, with solder flowing into the through-hole.
Too little leaves exposed copper
Too much solder creates a “blob”		 Add or remove solder as necessary
No flux residue
Excess flux residue		 Clean with 95%+ isopropyl alcohol and a brush

No bridging
Solder bridges between adjacent pads		 Use desoldering braid or a solder sucker to remove excess solder

Keep the soldering iron tip clean and shiny

Using a brass sponge or damp sponge, regularly clean the soldering iron tip to remove oxidation and old solder.

If something is hard to solder or taking too long, the tip is probably dirty.

Use flux

Flux helps clean the surfaces to be soldered, improves wetting, and prevents oxidation during solder

Rosin-core solder has flux built-in, but additional flux can be applied for better results.