Adding engine pencil zinc to 2004 3GM30 M21

[captainmike]

it is a mystery to me that some engines such as my Yanmar 3GM30 that powers my Ranger Martini M21do not have the protection of a zinc anode.

The AURA is docked at a large marina 680 slips next to a steel hull vessel with an aluminum yacht close by and older dock wireing.

an elegant solution is to install a Sen-Dure unit mine is in the raw water line after the sea strainer before the sea water pump and grounded to the engine block.

I change the zinc once a year and at $40 it is cheap insurance.

Are there any other Martini owners ?

Capt. Mike

Just got back from an 8 day cruise of the Florida Keys made it down to Key West I have canvas that encloses the bow section and have the boat set up for cruiseing.

 

[abcandjrc]

Do you see appreciable damage to the pencil zincs when you replace them?

We have had engines with and without heat exchanger zincs (Yanmar 4JHE - no, Ford-Lehman 2704ET - yes). I inspected the zincs in the Lehmans annually but the only measurable loss was to what I assume were the many-years-old ones I replaced when we bought the boat. They were present only in theory!

As you point out, I suspect that the need is kind of like the location rule in real estate. Irrelevant to us for now since our 21 sits on the trailer.

 

[captainmike]

Yes I do see the zinc being about 1/3 used after a year.

I had volvo 4 cyl diesels in another boat and the former owner neglected the engine zinc and the brass in the heat exchanger was red-pink in color showing deterioration.