When bonding or grounding connections between dissimilar materials, what practice helps manage corrosion?

• A. Use a suitable washer so that any corrosion will occur on the washer
• B. Use insulating washers to isolate
• C. Apply paste to prevent corrosion
• D. Overtighten the fastener to ensure contact

Answer: (D)

When two different metals are bonded or grounded together in the presence of moisture, they form a galvanic couple and corrosion can occur at the joint. The most effective way to manage this is to break the electrical path between the metals by using insulating washers, so the metals are not electrically connected at the joint. This isolation prevents galvanic current and significantly reduces corrosion at the connection. Other approaches may have situational uses, but they don’t reliably prevent galvanic action and can cause other issues; overtightening can damage parts and won’t stop the corrosion process. Isolation with insulating washers is the reliable way to control corrosion in dissimilar-material bonding or grounding.