What type of solder should not be used for wiring repairs?

Acid core solder should not be used for wiring repairs because it contains an acidic flux that can corrode electrical connections and damage the wires. This type of solder is typically designed for plumbing and metalwork applications, where the acidity is necessary to clean the surface of metals for a strong bond. However, in electrical wiring, the corrosive nature of acid core solder can cause serious issues, including potential failure of the connection over time, leading to possible safety hazards and malfunctions.

In contrast, rosin core solder is specifically formulated for electrical work, utilizing a non-corrosive flux that helps clean surfaces without harming the wires. Low-temperature solder can also be used effectively in wiring applications, especially when components are heat-sensitive. Lead-free solder is now common due to health regulations, and while it has different melting properties compared to leaded solder, it is also designed for electrical use and is safe for wiring repairs.