What is tinning in soldering?

• A. Applying a thin layer of soft solder to the ends of wires before soldering them.
• B. Cleaning the wires prior to soldering.
• C. Heating the solder until it flows.
• D. Covering wires with insulation before soldering.

Answer: (A)

Tinning is coating the wire ends with a thin layer of solder before you join them. By applying flux and melting a small amount of soft solder onto the conductor, you create a solderable surface that wets well when you later apply heat to form the joint. This improves oxidation protection, helps the stranded wires stay together, and makes the final joint easier and quicker to form with a clean, reliable connection. It’s not simply cleaning the wires, nor is it just heating solder until it flows, and it doesn’t involve putting insulation on the wires. The essence of tinning is pre-coating the ends with solder to prepare for a good solder joint.