What precaution should be taken when riveting dissimilar metals together to prevent electrolytic action?

When riveting dissimilar metals together, placing a protective separator between areas of potential electrical difference is essential to prevent electrolytic action. This is because different metals can create a galvanic cell when they are in contact in the presence of an electrolyte, leading to corrosion of the more anodic metal. By using a protective separator, such as a non-conductive coating or material, the electrical connection between the two dissimilar metals is interrupted, greatly reducing the risk of corrosion.

Other options may not effectively address the issue of electrolytic action. For example, using a thicker rivet does not mitigate the risk of galvanic corrosion, as it does not alter the electrical properties of the metals involved. Applying a conductive lubricant could actually facilitate electrolysis rather than prevent it, since it may allow for easier conduction of electricity between the metals. Heating the metals before riveting alters their physical properties and may affect the integrity of the joint, but it does not prevent electric interaction between the dissimilar metals. Thus, employing a protective separator is the most effective approach to safeguarding against electrolytic action.