Shaft Zincs - Bene 343 Oceanis

WhiteNow

WhiteNow

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Jan 2, 2015
35
Beneteau 340 Oceania ventura
Anyone out there familiar with the 340 Shaft Zincs.
Was told by a diver that my Strut boss or Stern tube needs a zinc. That it was suffering from oxygen depletion type corrosion.

I attached a few pics of different zinc set ups and see one person painted, another has three zinc and I'm speaking of the largest one closest to the hull and that it's 2"

Boatzinc.com in Fla said it looks like a C-9 but has never seen anyone put a zinc on that stern tube and didn't know that it was a Steel part.

Thoughts and suggestion?
 

Attachments

BigEasy

BigEasy

.
Jun 21, 2004
2,900
Beneteau 343 Slidell, LA
I have never seen a zinc collar placed on the stern tube. Not saying that it is incorrect; however, I have never heard of anyone doing it. I have a Volvo folding prop on my 343. I only use a one inch thick collar type zinc on the prop shaft between the stern tube & prop. It typically lasts about six months. On my last haulout in March '14, I did notice a bit of corrosion on the shaft tube. I painted it with Interlux 2000 epoxy. Come to think of it, if it is crevice corrosion, I may have done more harm than good by painting it.
 
N

Newport Bob

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Jun 23, 2013
271
Beneteau 373 Newport
I have a similar arrangement on my 373. Was debating between adding a shaft zinc or a line cutter - not room for both.
Then I found the salca;
http://www.marineanodes.com/page/sacrificial-line-cutters

My dealings with Marine Anodes has been great - price, service, info, etc. And for you they are in Calif.

Re your question about the zinc on the shaft log; I may be wrong but I don't see how it would provide any protection. The log is captured in the fiberglass and holds the cutlass bearing. Therefore, no contact to other metal - isolated from the shaft by the rubber cutlass.
 
Gunni

Gunni

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Mar 16, 2010
5,937
Beneteau 411 Oceanis Annapolis
Newport Bob said:
Re your question about the zinc on the shaft log; I may be wrong but I don't see how it would provide any protection. The log is captured in the fiberglass and holds the cutlass bearing. Therefore, no contact to other metal - isolated from the shaft by the rubber cutlass.
Click to expand
Exactly, the log does not need a zinc.
 
K

Ken_Smith343

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Sep 21, 2014
17
Beneteau 343 Mimico
Looking for advice on my "new to me" prop situation. Looks like I have some corrosion going on. The only SA I have is the one on the end of the shaft. This type is also new to me. Are they easy to find? Do they typically work as well as standard on shaft types? Any suggestions on what to do with the prop before I relaunch? Ken
 

Attachments

N

Newport Bob

.
Jun 23, 2013
271
Beneteau 373 Newport
Check my link above - various Beneteu zincs that might work for you at prices better than West Marine
 
DougM

DougM

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Jul 24, 2005
2,242
Beneteau 323 Manistee, MI
Ken_Smith343 said:
Looking for advice on my "new to me" prop situation. Looks like I have some corrosion going on. The only SA I have is the one on the end of the shaft. This type is also new to me. Are they easy to find? Do they typically work as well as standard on shaft types? Any suggestions on what to do with the prop before I relaunch? Ken
Click to expand
The prop in the picture looks as if it has some minor surface pitting that could be simply buffed out. It's difficult to tell from the photo if it is anything more serious.
The shaft anode shown is fairly common to Beneteaus. Check this site as a source or boatzincs.com.

Since I'm in fresh water, I am curious as to whether six months or less is considered normal deterioration for a zinc anode. I use magnesium, which is not as easy to find. I have not seen any degradation in five years.
 
Ron20324

Ron20324

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Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
The original post, the left-hand photo, is what most current Beneteaus are faced with. The zinc is 3/4 inch thick. Most "collar" zincs you'll find in stores are 1-inch. You'll need to know the shaft diameter (25mm/one inch?).

http://www.boatzincs.com/beneteau-collar.html has both the collar and end-of-shaft anodes- even in magnesium, Doug.
 
cymeyer

cymeyer

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Jul 8, 2005
522
Jeanneau 389 Grosse Pointe Farms, MI
Hey Doug,

I have a MAXPROP and I am pretty sure it is a zinc anode. I use in fresh water (lake st clair) and never get pitting. I clean every year with a Dremel and it works fine.

Not sure if Magnesium is better to use. What is the difference?

Chris


DougM said:
The prop in the picture looks as if it has some minor surface pitting that could be simply buffed out. It's difficult to tell from the photo if it is anything more serious.
The shaft anode shown is fairly common to Beneteaus. Check this site as a source or boatzincs.com.

Since I'm in fresh water, I am curious as to whether six months or less is considered normal deterioration for a zinc anode. I use magnesium, which is not as easy to find. I have not seen any degradation in five years.
Click to expand
 
DougM

DougM

.
Jul 24, 2005
2,242
Beneteau 323 Manistee, MI
cymeyer said:
Hey Doug,

I have a MAXPROP and I am pretty sure it is a zinc anode. I use in fresh water (lake st clair) and never get pitting. I clean every year with a Dremel and it works fine.

Not sure if Magnesium is better to use. What is the difference?

Chris
Click to expand
Chris.
Salt water Is more electrically conductive than fresh, so zinc works well. The recommended choice for fresh water is magnesium because of its relative position in the periodic table. Thus, it should be more protective as a sacrificial anode. It's remotely possible in the Great Lakes that one could get by with no sacrificial anode at all if it were not for stray electrical currents around marina docks etc.

The prop in the photo is not mine, and evidently lives in salt water. I have not seen a prop from a fresh water environment that looks like that one. However, that may be because we cannot leave our boats in the water year around.
 
K

Ken_Smith343

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Sep 21, 2014
17
Beneteau 343 Mimico
DougM said:
. The prop in the photo is not mine, and evidently lives in salt water. I have not seen a prop from a fresh water environment that looks like that one. However, that may be because we cannot leave our boats in the water year around.
Click to expand
If you are talking about my picture, as far as I know, it has been in Lake Ontario all its life, but the boat is new to me last June. I'm not sure of the material of the SA on it, but I plan to replace this year with magnesium. I will also add the collar type of there is room, as the other pics show.

Chris. What bit do you use on your drummer to clean up your prop? I think I have a wire brush wheel, but I would assume it should be of a softer metal, rather than steel.

Ken
 
cymeyer

cymeyer

.
Jul 8, 2005
522
Jeanneau 389 Grosse Pointe Farms, MI
Hey Ken,

I use a small stone wheel (drum shaped) on the Dremel. I put on low speed and am very gentle. I only want to grind off any debris and get down to the zinc. It works very well. I think having the zinc exposed to the water is a good thing.

Chris


Ken_Smith343 said:
If you are talking about my picture, as far as I know, it has been in Lake Ontario all its life, but the boat is new to me last June. I'm not sure of the material of the SA on it, but I plan to replace this year with magnesium. I will also add the collar type of there is room, as the other pics show.

Chris. What bit do you use on your drummer to clean up your prop? I think I have a wire brush wheel, but I would assume it should be of a softer metal, rather than steel.

Ken
Click to expand
 
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