Zinc Question

I will throw this one in the mix, I had been talking to a guy at a local Sea Ray dealer about this and he said Sea Ray doesn't want you to put it on their shafts because it creates a disturbance in the water before the prop.

I couldn't see it doing that since my boat has them with no issues at all? Maybe something to do with the tunnels?
 
It may be me, but when I took them off, my gas mileage instantly went back up to what it had been before they were put on for several months.
 
Gee....maybe I should remove that strut thingy in the way of the props too...after the Marine Max service manager told me they've never changed a tranny filter on the ZF drives on the 40DA because those trannys didn't have filters I don't ask MM for maintenance advice any longer
 
Some here may recall me as being a staunch SR fan and 2X owner (still am) and I have a lot of respect for Sea Ray engineering and design. BUT somethings they do are well silly and in some cases foolish.

In the case of the Bonding system and Zinc anti corrosion system, I'd say it is a great system as long as you do not put the boat in the water. To vindicate me and my previous statement, here are the things to find and add to the maintenance schedule.

1. Condition: In the bilge all the green bonding wires will be led to numerous buss block. These common bars are then led to a gang bar to the the bilge end of the hull zinc bolts protruding into the hull below the waterline.

Problem: The buss blocks are often located in impossible to reach locations ie. under generator platforms , behind or under battery platforms, under cablemaster tubs, behind exhaust manifolds and fixed panels to mount battery chargers, fuel filters and other gear. Hence, you can not see nor sensibly repair a broken wire without dismantling half the ER. Now you have to fix the broken bond wires, no question on that, but you may choose as I have done which is to abandon inaccessible broken wires and set new accessible blocks for new bond wires as the old fail. BUT and this is a big one, you can not easily and frequently get to these swaged terminal ends to assure yourself they are still ship shape. Thus, installing a little more zinc to shafts is simply good insurance.

2. Some important and expensive parts were never bonded in the origional SR design. NO protection whatsoever!

Where? On Sea rays with 450 mechanical aftercooled Cummins, for one. Check the raw water crossover pipe, the exhaust elbow, the fuel cooler and the transmission oil coolers. These are all isolated and unbonded and guess what, all are common points of failure. Have the boat surveyed for galvanic corrosion and they will all test galvanically hot on the these 450's.

On my 460, bond wires were not led to my shaft struts and were not protected by a shaft bond in that the shaft cutless bearing isolates the strut. Wires were needed to bond the strut bolts.

So for two reasons, I do not give the medal of infailibility to SR on anti corrosion, but I do trust the periodic table and hence use more zinc.
:smt038
 
Good post Chad. I remember your previous information on bonding the 450C coolers and I will check before she comes out of storage. Perhaps our fresh water in the Great Lakes isn't so hard on the bonding systems as in your coastal boating experience.

James
 
Hi James,

Thanks for remembering. I think your engines will be slightly different but some of these issues are in your design as well. I think (check your self tho) your ZF tranny's have the cooler thrwartship over the tranny and it has a pencil zinc. The rest of what I said here previously prevails for you.

These little flimsey bonding gang blocks are principally under the batteries, the genny and outboard along the engine mount rails in the aft end of the bilge.

On my 460 I have two very pesky bond connections. These are both on the rudder shaft quadrants. These is a lot of back and forth movement and the super thick gage wire is too inflexible to take the constant bending and the wire breaks every few hours of operation. I'm going to switch to a flat braided copper cable (Sail boat engine and shaft bonding) and solder a cringle connection on each end to pass a bolt through to the quadrant. Maybe it wil be more flexible.

James make sure your shaft struts are bonded.
 
On my boat, these are readily accessible and seem to be clean and in good condition. Periodically, I rotate the screws to knock off corrosion. It would be interesting to run a continuity check between the transom zinc mounting bolts and the shafts when the boat is dry, wouldn't it? Then, you could keep the check going while rotating the props by hand.

Also, my transmission heat exchangers, a weak failure point on my boat, were not tied in. Someone here pointed that out, so I added a wire to each.
 
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I have been using shaft zincs for three of the last four years, two on each shaft. Sea Ray and the local dealer said I didn't need them, my diver persuaded me otherwise. On examining the shaft zincs after each six months they really haven't worn much, so I'm not going to bother replacing them this year.

On my 480, the bonding busses are pretty easy to get to to check.
 
OK, so here is the poop.... I have had zincs on my shafts since I bought the boat. The previous owner had zincs on the shafts, the owner before that and so and so forth......
But last spring when I had the boat hauled to have a bow thruster installed, I did my bottom paint, pulled props and did my zincs all myself. I was not on CSR yet and had no clue about tapping my shaft zincs and then re-tightening them..... So, they last all of a month, then when putting the boat in reverse and then forward to get into the boathouse I heard a loud thunk/clunk and thought that is weird. I had diver under the boat the next week and the zinc was gone off of the shaft and the starboard prop had a brand new $300 ding in one of the blades....Happy days !!
Yes, I believe in shaft zincs, but make sure they are tapped and tight....
 
Surfside 3 installed zincs on the shafts initially, and I've been installing them every since. My problem is they erode to nothing before the end of the season. So they are doing something, right? I checked them last year in July, August and Sept and they were almost totally gone by the end on Sept. So this year Boatzincs has a Shaft Zinc X-7H, the "H" stands for Heavy. It's twice the weight of the X-7 and hopefully will make it through the season. I do install them using the hammer method.

There are also the Godfrey Corrosion Collar Zincs, which have a brass collar, and are the same weight as the X-7H, the bass collar stays on shaft even after the zinc is gone. They expensive, about $50 a piece. If the X-7H zincs don't work, I'll try these next season.
 
Interesting....SS3 in NY recommended against shaft zincs....I use them anyway. Mine are typically about 60% wasted by the end of November but instead of using the heavy zincs I put on two per shaft.

Surfside 3 installed zincs on the shafts initially, and I've been installing them every since. My problem is they erode to nothing before the end of the season. So they are doing something, right? I checked them last year in July, August and Sept and they were almost totally gone by the end on Sept. So this year Boatzincs has a Shaft Zinc X-7H, the "H" stands for Heavy. It's twice the weight of the X-7 and hopefully will make it through the season. I do install them using the hammer method.

There are also the Godfrey Corrosion Collar Zincs, which have a brass collar, and are the same weight as the X-7H, the bass collar stays on shaft even after the zinc is gone. They expensive, about $50 a piece. If the X-7H zincs don't work, I'll try these next season.
 
A lot depends on where your boat is slipped. Lotsa stray current in the water is going to make swiss cheese out of your anodes regardless of the electrolyte content of the water or the functionality of your bonding system. It's a wonder mine last as long as they do. There are more wires dangling in the water at our place than on the space shuttle.
 
It was SS3 in Norwalk that installed them. I think he told me to either put them on or double up on the stern zinc. My stern zinc is 60% done by the end of the season. The trim tab zincs are maybe 30%.

I do believe the marina had too much stray current, based on other boats aside of me, having to replace zinc mid-season. Plus the shaft zinc closest to the dock erode faster then the other, so it's clear there is more current close to all the wires in water.

We're moving marinas this season, to a marina with brand new docks, so hopefully there will be less current in the water.

It's interesting in that most of the SR in the Marina we winter / store at, have shaft zincs. I think most people go with the advice of the marina.
 

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