shaft zinc and hanging zinc

[nzfisher]

Has anyone put a shaft zinc on an R25? I replaced a prop zinc that "disappeared" after 5 months in the water so I am thinking of putting a shaft zinc above the prop as well. I also have purchased a hanging zinc but I am not sure of the best way to connect it. Any experience out there?

thanks

 

[walldog]

The hanging zincs connect to the ground system of the boat. The easiest place to connect is the negative terminal of your batteries with the supplied clip. You can also remove the clip and crimp a terminal in its place to secure it under one of the battery studs.

Just do not forget to bring the guppy in before casting off.

 

[Ken Boyd]

If you have not already done so, recommend you install a galavantic isolator. I installed one on my R-25 at the start of the 2012 boating season and it cut the anode errosion rate by more than half over what it had been in 2011.

Rather than installing a shaft zinc, have you considered installing a clam shell type rudder zinc to supplement the prop zinc. You will need to drill a hole in the rudder to install it but that is fairly easy to do when you have the boat out of the water.

 

[trailertrawlerkismet]

In addition to Ken Boyd's good advice about the rudder zinc I would add one thing. My research found, when I installed a rudder zinc on a prior boat, that the zinc should be installed as high up on the rudder as possible. As I recall the higher the install the less sensation (or any sensation) there is from adding the zinc pancake zinc to the rudder.

Jim F

 

[nzfisher]

Thanks for the ideas. I now know where to attach the hanging zinc and will put a note on the list of things not to forget when i cast off. I haven't seen many, if any, anodes on rudders at this time but I will check that out as I haven't been looking.

Most of the commercial trawlers (almost all) have shaft zincs to prevent the corrosion damage to the underwater systems and the related connections to the interior of the boat. Since these guys are in the water all the time except once a year for haul out, I was hoping that someone else in Tugnuts was using the main shaft zincs as well. I will fish for a response on the shaft zinc one more time.

 

[baz]

I keep our 2010 R-25 in salt water year round.

On our boat the rudder hinge is bonded with a 1" wide braided cable to the boat's bonding system (the engine block in my case). You can view this 1" braided cable by lifting out the removable hatch inside the cockpit transom's cupboard.

I installed a year ago the following items

1) A large starboard side transom mounted zinc (about 8"x6"x0.5") that sits just below the water line. It is bonded to my prop shaft brush.

2) A prop shaft brush that connects to a transom zinc and is bonded to the boat's bonding system (the engine block in my case)

3) A ProSafe Galvanic Isolator (this unfortunately is quite a spendy item. It is quite easy to install once you figure out its placement)

4) Donut anodes to the base of each swim step 7/8" dia brace strut (these barely dip in the water unfortunately, but do seem to be working)

5) Bonded the trim tab plates to their adjacent hinge plates attached to the transom using a quality SS wire. This was done as the hinge is simply a loose crimp design with poor contact surfaces and the hinge plates on the transom along with one or more of its securing screws/bolt heads had started to corrode badly.

I have not employed the hanging sacrificial guppy zinc as it has received little support by quite a few TugNuts here.

Monitoring my underwater anodes/zincs for past year leads me to believe I have more than halved the erosion rate of these.

Specifically, the Prop zinc is now lasting 6 months vs. 3 months. The Thruster zincs have gone from every 3 months to an estimated 9 months. The trim tab zincs seem to last for ever now. The transom mounted 8"x6" zinc is eroding slowly and after one year I would estimate it has at least another year or two before needing replacement.

I typically have the underwater zincs replaced if they are at 50% or less gone since last examined. The idea being that 100% gone is never reached.