Sacrifcial zinc - where do i ground it

[NewWest]

I am still new to boating in salt water and need advice on sacrifical zincs.

It has been suggested to me to hang a sacrificial zinc overboard and then connected into my boats ground system. I have a R-29.

My question is where do i connect to the grounding system?

 

[LADYBUG TOO]

There are several convenient places to ground the zinc in the port side aft locker. Use an alligator clip and make sure there is a break away connection to the zinc so that if you forget to disconnect it, it stays behind at the dock and not fouled in your prop. Any negative battery terminal will do. Also, frequently check the bonding wires connecting the ground system to your thru hulls and other metal components. Ranger is good about bonding everything at the factory but it is up to you to keep the system clean. Deal with corrosion as soon as you notice it. There are several spray on corrosion inhibitors available.

Pat
Ladybug, Too

 

[NewWest]

Thanks Pat.

How deep in the water should i place the zinc fish - and should it be close to my prop.

I also thought I had read not to attach the alligator clip to the battery? Any thought on that.

Someone else told me just to attach it to the engine block - do I need to fine bare metal or can I clip it to any painted part of the engine block?

Thanks again for the advice

 

[LADYBUG TOO]

It needs to be on bare metal and yes it is probably not best to tie directly to the battery terminal but there are two or three ground buss bars in the vicinity. Anything painted will inhibit grounding so pick a bolt, clean it with a wire brush and attach a lug to connect your zinc ground. I would attach the zinc to the dock as close to your prop as you can and have a clip point hanging nearby so it will pull free if you forget to disconnect. Get about 2 ft. submergence though I don't think it is that critical.

Pat
Ladybug, Too

 

[NewWest]

OK

Thanks again for the advice

 

[knotflying]

Excerpt from a Boat US article:

There are other sources of electrolysis that you can't correct. The boats on each side of you in the marina may be connected together through the dock ground lead and one may be eating up the zincs rapidly on the other. If you sit between them, this current may take a short cut by going in an item near one boat and exiting via your zinc near the other. This will eat up your zinc too, even though you are not connected to the other boats. The best solution here is to use zinc fish while you are at the dock. They are large lumps of zinc, often cast in the shape of a fish, that are cheaper and easier to replace than the zincs on your shaft.

The "fish" come with a copper wire already attached which is also used to hang them in the water. They have an alligator clip on the end of the wire and this should be connected to the negative bonding circuit on your boat. If it is not conveniently available in the cockpit in the vicinity of the prop, you might consider installing a stainless bolt for clipping it to, with the head of the bolt inside the deck connected to the negative bonding system. Clipping it to the shrouds or railing will only work if somewhere on the boat the shrouds are connected to this boat negative bonding system.

The full article. http://www.boatsafe.com/nauticalknowhow/012000tip3.htm