Adequate Zincs

[F4d3d]

Hello All!

I'm dropping a new-to-me sailboat (a thread on this soon!) into the water tomorrow. There is currently only one old zinc on the prop shaft, and no others anywhere else on the boat. The strut was just replaced with a newly crafted stainless steel one, and I never saw the old strut, so I'm unsure if there was a zinc on it or not.

How do I know the appropriate amount of zincs to use, and if one should be added to the strut?

Thanks!

[DulceSuerna]

Forgive my typing, (rum)
I have a zinc on the shaft, one on my rudder, and one in my heat exchanger ( I replace every 2 months), it is a small pencil zinc, and dissolves fastly. Without a doubt replace the old zinc with a new one on the shaft.
My 2 cents.

[jackdale]

Agree with DS.

One on the prop shaft and and IN the heat exchanger, at least.

[paul323]

Personally I have 2 on the shaft, and the pencil in the heat exchanger.

I'd also suggest you check it/them regularly, at least initially. I am in a 'hot' marina, and 2 zincs only last 6 months (!!!). I have just installed a galvanic isolator - it'll be interesting to see of it helps.

[Faster]

A couple of zincs on the shaft, the strut zinc is probably overkill.

Congrats on the boat.. where will she live? Pics required, of course!

[Fstbttms]

Originally Posted by Faster

...the strut zinc is probably overkill.

The only reason to install a zinc on the strut is if there is evidence of corrosion. Otherwise, leave it be. I have seen struts break where they are drilled for zincs. Two on the shaft may not be strictly necessary but is good insurance.

[F4d3d]

Thanks for the replies everyone. We'll put two new zincs on the shaft, and one in the heat exchanger. I may have some questions about the heat exchanger zinc tomorrow after I have a closer look at it.

Originally Posted by Faster

Congrats on the boat.. where will she live? Pics required, of course!

An introduction thread and pics are on the way soon! We're planning to sail her to French Polynesia in a few months, so she won't have a permanent home any time soon.

[DulceSuerna]

Originally Posted by paul323

Personally I have 2 on the shaft, and the pencil in the heat exchanger..

My shaft is just too short to fit 2 or I would of, wait that doesn't sound right does it

[boomvangdc]

This article might be helpful: Zincs: Can you have too much of a good thing? | Daily Sailing News from North American Sailor.

In reference to the comment about being in a "hot marina" and my own experience (using a freshwater zinc in saltwater - not a good idea), I recommend having you or someone else take a look at the zincs periodically while the boat is in the water to see how quickly they are depleting.

[sailingdog]

I'd point out that if you even suspect your marina as being a "hot" marina, don't dive on the boat in the marina...anchor out someplace away from any stray currents to check the zincs...