Premature heat exchanger zinc wear

[gabosifat]

Hello everyone,
I’m wondering if others have experienced rapid heat exchanger zinc wear?
The engine is a Universal M35A. In April we removed heat exchanger, cleaned it with muriatic acid and changed the HE pencil zinc and painted it. Now while working on the transmission replacement we had to remove the HE. Checked the zinc, and it had completely eroded away (in only 4 month!). The boat left our marina May 3rd and has been cruising all that time with minimal time in any marinas. Looking for suggestions as to why it should erode so quickly. Thanks to all who reply!
Cheers,
Steve Gabbott
E35/3 Silent Dancer
Gabriola Island BC

 

[Frank Langer]

Hello everyone,
I’m wondering if others have experienced rapid heat exchanger zinc wear?
The engine is a Universal M35A. In April we removed heat exchanger, cleaned it with muriatic acid and changed the HE pencil zinc and painted it. Now while working on the transmission replacement we had to remove the HE. Checked the zinc, and it had completely eroded away (in only 4 month!). The boat left our marina May 3rd and has been cruising all that time with minimal time in any marinas. Looking for suggestions as to why it should erode so quickly. Thanks to all who reply!
Cheers,
Steve Gabbott
E35/3 Silent Dancer
Gabriola Island BC

Steve,
Our pencil zinc in the heat exchanger usually lasts 5 to 6 months sailing on the inside coast of BC Vancouver Island. I sail year round, with regular day sails and several multi-week trips each year. I know that some sailors have their pencil zincs last much longer, but my guess is that it depends on how much you sail/use your engine, and how much water is running through your heat exchanger. With you cruising alot during that time, that might have speeded up wear on the pencil zinc.
It will be interesting to hear from others on this site as to their experience.
Frank

 

[Christian Williams]

That's my experience, too, more or less. I just put in a galvanic isolator, we'll see if it makes a difference.

 

[Frank Langer]

That's my experience, too, more or less. I just put in a galvanic isolator, we'll see if it makes a difference.

Christian,
Please let us know at some future time if the galvanic isolator has made a difference, in both the pencil zinc and the prop shaft zincs. I've been tempted to buy a galvanic isolator, but have not done so yet.
Thanks,
Frank