Galvanic Isolator With an Isolation Transformer

Question:

First,  congratulations on your website and very instructional videos.  I have a French aluminum sailboat, that was converted from 220 V to 110 V with an Isolation Transformer three months ago. Last week we discovered that there was corrosion attacking the boat because the power outlet in the boat was connected to the aluminum hull via 4 screws (not isolated). The company that fixed the problem is suggesting the installation of a Galvanic Isolator, regardless of my Isolation Transformer.  What is your opinion? Thank you very much, Jeff.    - Homero

Answer:

Hi Homero, glad you find the PYS website and YouTube videos informative. With an isolation transformer already installed there is no reason to install a Galvanic Isolator. According to what you describe, there was metal to metal galvanic corrosion and NOT stray current corrosion. Neither an isolation transformer or a galvanic isolator will prevent galvanic metal to metal galvanic corrosion. Properly isolate both metals from touching.  - Jeff