[C320-list] Zinc Or Aluminum Anode For Mid Chesapeake?

[Bruce Hunter]

OK, I believe I have it down. On the Chesapeake from the head to just North of Baltimore is considered "fresh"Then there are 3 classes of brackish below that point. It is Oligohine where the salinity is .5 to 10 ppt (parts per thousand) is from north of Baltimore to the Bay Bridge. It is Mesohaline (salinity 10.7-18.0ppt) from the Bay Bridge to the Rappanannock (medium salinity). It is Polyhaline (18.7-36ppt)  from the Rappohannock to the ocean (36ppt is ocean water). So if Aluminum alloy anodes are made for brackish water the Chesapeake is definitely the place to use them.  Also, I read a zinc anode can form a layer of zinc oxide insulating itself, then the protected metal will deteriorate. So upon reading this I've ordered all aluminum alloy anodes (Non Chinese) and will put on our boat.
 
Bruce
Nauti Time #719

From: Tony Murphy <tony at midwestphysics.com>
To: "C320-List at Catalina320.com" <C320-List at Catalina320.com> 
Sent: Wednesday, March 6, 2013 5:05 PM
Subject: Re: [C320-list] Zinc Or Aluminum Anode For Mid Chesapeake?

Geesh... I've heard it all now!!  

Does this manager have a clue? Does he realize that Zinc and Magnesium are the environment???  These are naturally occurring elements...


Tony
Bella Sol #886


Sent from my iPhone

On Mar 6, 2013, at 3:05 PM, Warren Updike <wupdike at hotmail.com> wrote:

> The manager at our store said aluminum is less damaging to the environment than are lead annodes. They are only stocking aluminum now.
> 
> -----Original Message-----
> From: Bruce [mailto:swampcreek42 at yahoo.com] 
> Sent: Wednesday, March 06, 2013 1:56 PM
> To: C320-List at Catalina320.com
> Subject: Re: [C320-list] Zinc Or Aluminum Anode For Mid Chesapeake?
> 
>> From what I've been reading, the less conductive the water the less noble the anode should be so the order goes zinc, aluminum, magnesium. Zinc for salt, aluminum for brackish and salt, magnesium for fresh. I guess I might be reading into this too much but now I have to get to the bottom of it. Thanks for the tip on Chinese abides from WM, I'll remember that.
> 
> Bruce
> #719
> 
> Marshall <marshall at merry-thought.com> wrote:
> 
>> Everyone that I know on the Chesapeake including myself use zinc. My boat is across from Annapolis. To my knowledge boaters in the Northern part of the bay use zinc. I would avoid the Chinese made Worst Marine zincs. I am going to check out Fawcetts. Defemder also sells non Chinese zincs.
>> 
>> Marshall
>> 
>> Bruce <swampcreek42 at yahoo.com> wrote:
>> 
>>> I was about to order a new anode For our FOF prop when I saw that 
>>> aluminum alloy is decided for brackish water. I used to just put zinc 
>>> on everything and not think twice but being that the mid Chesapeake is 
>>> brackish I'm thinking that I should replace the prop AND shaft abides 
>>> with aluminum alloy. Any thoughts?
>> 
>> --
>> Sent from my Razor Max with K-9 Mail
>> 
>> Marshall
>> 
>> Marshall, Diane &
>> The Merrythought Poodles
>> SV C-320 Merrythought  #1037
> 
>