EMC Question of the Week: December 31, 2018
To prevent galvanic corrosion and ensure a good electrical bond between two dissimilar metals, it is advisable to
- put a thin coat of varnish on both metal surfaces
- paint the surfaces after the connection is made
- use a conductive gasket
- any of the above
Answer
The best answer is "c." Using a conductive gasket, washer or plating that is a better match for both metals can greatly reduce the rate of galvanic corrosion. Varnish can prevent corrosion, but destroys the electrical bond. Painting after connecting is not generally a reliable means of reducing the rate of corrosion. Painting can also hide corrosion, preventing any action from being taken until the connection is severely degraded.
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