Zincs

[David Irvine]

My boat was delivered with only one small zinc fitted on the P bracket. Since then I have fitted a zinc on the prop shaft. I am finding however that there is galvanic action on several places including the hot water tank and the steering quadrant. What do other owners recommend regarding anodic protection? How many zincs and connected to what? Has anybody any information about the 'zinc saver' that Catalina now fit to new boats?

 

[Ernie April]

Galvanic Isolator

Hi, Dave-Since Catalina uses ProMariner chargers, I suspect that they are installing the ProMariner Galvanic Isolator in ground wire of the shore power connecrtion. These consist of a couple of diodes that prevent low-current leakage - the source of galvanic action - but open when necessary to provide a good ground connection. This was the subject of an article in a recent Practical Sailor - which I seem to have misplaced. It is agreed that galvanic isolators work. The problem with galvanic isolators is that they should have "always-on" test circuitry because a blown diode means no ground available which can be lethal. The ProMariner unit has no or limited test circuitry and is less expensive (about $100). There is one unit made outside the US with full test circuity that goes for about $500. Amazing that the test curcuits cost 5x more than the working circuit.Cheers--Ernie