Shaft Zincs

[osd9]

I just got a call from the marina and they wanted to know if I wanted them to install shaft zincs on my boat. On the last 3 inboard boats that I have owned, I have always put shaft zincs on. Except for the first time (after learned the proper way to set a shaft zinc) I have never had a problem with them coming loose or causing damage. The service manager said that Sea Ray no longer installs shaft zincs. He said that Sea Ray told the resellers that the zincs had a tendency to come loose, slide down the shaft and cause damage.

I asked the service manager if I don't put zincs on the shafts, what would protect my props and shafts. He said that they are bonded through the engine to the hull zinc.

I gave him the OK to NOT install shaft zincs......

What do other guys do.......? Oh...and do you paint your shafts...?????... :huh:

 

[fwebster]

This is a debated point; one that will get a bunch of different responses, I'm sure. But here's one opinion:

I use shaft zincs. I'm not buying the idea that the shaft and prop are properly bonded through their connection to the engine. How can there be complete continuety in the bonding circuit if the shaft is separated from the transmission case by clutch packs and transmission fluid? I just figure the extra work to properly seat and tighten the shaft zincs is worth the protection.

And that's another point....if the shaft zincs are not correctly installed, you can sling them off . It seems the larger the shaft the worse the problem, so if you use them, be sure you install them correctly.

 

[ImpulseIII]

I second what Frank said. I use shaft zincs and have not had a problem since the first season when I lost both of them during the season (I suspect it was a faulty installation (mine)).

I do not paint the shaft or props but I have seen others painted. Not sure what the proper answer is but I have no plans on painting either.

My new dilemma is bottom paint. I have been using Micron66 which has self ablating properties (you do not need to be moving for the paint to work). Problem is that "66" does not work in fresh water which is what we have at Skipjack Cove soooooooo I have to try another type. Not sure what I will do just yet. Just my $.02.

 

[Robski97]

I called searay last year about this . They said they dont want zinc's on the shafts. My marina as frank said disagree'd 100 %

I ended up putting them on . My shafts we painted blk at the factory. When the boat was hauled at the end of the season the zincs were 80 % gone.

So draw ur own conclusions


Rob

 

[osd9]

The more I think about it the more I already knew what I really wanted to do......

I will call the yard and have my own decision reversed.....

you know.....I knew it in my gutt...but when the yard starts saying that they don't suggest something, you always feel akward going against there "advise"......I'll just remind them to smack the zinc halfs with hammers a few times and then re-tighten the nuts a few times......afterall.....they don't install them that often so they may not know that..... :grin:

Thanks guys....appreciate the comments...

 

[rondds]

i've noticed that a lot of sundancers do not have shaft zincs. didnt really know why. in all my years of boating, until seeing this thread, i have never even considered NOT using shaft zincs, and i have never had a boat without shaft zincs. additionally, i have NEVER heard of any problem with zincs sliding down causing damage. i'll keep using them!

i've also noticed my boat (and other searays) have no rudder zincs (and no hole to allow for mounting). what's up with that? bonding system takes care of that too i guess.

 

[fwebster]

The rudders do have a bonding wire inside the boat connecting them to the boat's bonding system. The only way a shaft is bonded is thru gears, clutches and fluid which, it seems to me, cannot provide a continuous connection.

As far as installation, its a little more than smak the zinc and tighten it a few times. There is a little contact point midway down the sode of the zinc....that little tit must be put in contact with the shaft and crushed in place as tha bols are tightened equally on both sides. It usually takes tightening, rotating the shaft 180 degrees, tap the zinc, tighten the opposite side and then repeat that until you have done the fisrt side at least 2X.

 

[Skip]

I don't run shaft zincs. The Boat did not have them from the factory, and after two years in salt the tab and transom zincs were "well wasted" according to the survey last year wehen I bought her. I replaced all zincs when I hauled the boat out. One year later, in fresh water, after being berthed at new docks with new power supplies, I have discovered that my zincs are still in good shape. I felt around on both tabs and the zincs are fine. My maintenance schedule based on this experience will be to haul every other year and replace the tab/transom zincs, and forego shaft zincs.

regards
Skip

 

[osd9]

What's the nettles situation in BIH? I may have my tank and regs on board for the July rendevous...I'll dive under and check zincs for beers..... :grin:

 

[ImpulseIII]

For a six pack will you clean the bottom ???? :smt043 .

 

[PMvdb395DA]

The rudders do have a bonding wire inside the boat connecting them to the boat's bonding system. The only way a shaft is bonded is thru gears, clutches and fluid which, it seems to me, cannot provide a continuous connection.

As far as installation, its a little more than smak the zinc and tighten it a few times. There is a little contact point midway down the sode of the zinc....that little tit must be put in contact with the shaft and crushed in place as tha bols are tightened equally on both sides. It usually takes tightening, rotating the shaft 180 degrees, tap the zinc, tighten the opposite side and then repeat that until you have done the fisrt side at least 2X.

I think that a bounded slip ring around the shaft is a safe solution.
They can't come loose

Peter

 

[Divedaddy]

In our warm salt water area, I don't think many would normally NOT plan on using shaft anodes. We tend to put them on as pairs spaced such that the first one will keep a thrown shaft out of the rudder. We also paint the shafts and props, same as the hull, with hard bottom paint.

If you are concerned about slinging the anodes (shouldn't happen if properly installed) the consider using shaft brushes connected to the bonding system.

 

[osd9]

In my neighborhood, the entire canal system is slow speed/no wake.....with all my other boats, that simply meant, both engines in forward, no throttle, and enjoy the 5 minute ride out to the open bay. Not the case with Diesel....two engines in foward, at 600rpm, and I'm making a wake. So when I am in my canal, I have to ride with one engine in neutral, and one in foward....not fun keeping the boat straigt, but I'm getting use to it....

Anyway, about two weeks ago, I noticed that whenever the port engine was in gear and the starboard was left free wheeling in neutral, I would hear a high pitched squeal. It was bugging me, so I didn't use the boat much as I was waiting for my new props to come back from the prop shop (I'll post them in another thread) to haul and investigate. Well....this morning I got lifted and low and behold......the MarineMax yard didn't put the zincs on correctly and they shifted.......the starboard zinc was working its way into the strut and almost got the bearing. Two of the four screws onthe Port zinc were loose as well. I guess I now know why MM doesn't install zincs on shafts.....they havn't figured out how to get them to stay.....I was more than a little Pee'd, but I am very happy I got to the issue before it became a big job.

The local yard replaced the zincs and check the bearings and all is well......