How often does everyone replace thier Pencil Zincs

[Tom]

I am speaking of the pencil zincs in the engine heat Exchanger....(BTW I have a Universal M35B)1) How often does everyone check their Pencil Zincs? (I know on my M35B it says monthly).2) How long does everyone's last ? I only check mine yearly -- And it is Completely gone (I know SHAME on me - I will check more regularly)....3) How do you check it?a) Completely drain Antifreezeb) Just remove zinc, let a some antifreeze leak out while you check and/or replace with a new one?

 

[Tom Ehmke]

Tom-re: zinc pencils

My 1986 ODay 272 has a pencil zinc in the sea water cooling circuit. I removed it three years ago and replaced it with a new one. I sail in fresh water and as far as I know, it hadn't been replaced before. That would be 12 years in the heat exchanger and it didn't look worn. As a matter of fact, I kept it as a spare because it looks to have a considerable useful life yet. The boat is hauled seasonally, so the demands on the zincs are not the same as they would be under year-round use. Also, the zinc pencil in the heat exchanger of the Westerbeke 10-2 is installed in the sea water side of the heat exchanger, so I don't lose antifreeze when changing it, just a little water as I recall.Your post serves as a reminder to check it next spring.Thanks,Tom

 

[Tom]

Thanks....and just a note

I think my zinc is on the raw water side also....I think the reason I saw antifreeze is due to the winterizing of the engine.

 

[Don]

Mine last about a year in FL salt water.

I change mine each winter as part of my yearly maintenance. It is on the raw water side, so no anti-freeze comes out. Don't use thread tape, as that defeats the purpose of the zinc.

 

[Bob Todd]

Replacing Zincs

All my zincs get replaced annually or sooner if required. All are checked monthly.I hold a rag under the zinc on the cooling system and as soon as I pull the zinc I put my thumb over the hole. I have a spare at the ready and replace quickly. Minimal fluid loss.Cheers,Bob

 

[steven f.]

depends on hours

I change mine about every 25-30 hours. This is usually about three or four times a year. At these time intervals the zinc is about 50% gone. I feel it's better to do it too often than not enough even though it's a pain in the ass.