What should be used to neutralize nickel-cadmium battery cases affected by electrolyte?

Boric acid is the appropriate choice for neutralizing nickel-cadmium battery cases that have been affected by electrolyte. Nickel-cadmium batteries can leak electrolyte, which is corrosive and can cause damage or degradation to the battery case and surrounding materials. Boric acid has mild alkaline properties, making it effective in neutralizing the acidic nature of the electrolyte, thus preventing further damage and promoting safe handling.

Using boric acid not only neutralizes the corrosive substances but also can help in cleaning the area affected by the electrolyte. This property makes it particularly useful in maintenance and repair settings where safety and material preservation are paramount.

In contrast, other options like linseed oil or various naphthas do not possess the necessary neutralizing qualities for electrolytes and could even complicate the situation further by introducing additional contaminants or flammable substances. Therefore, the use of boric acid is preferred for its effectiveness and safety when dealing with nickel-cadmium battery electrolyte problems.