Zinc Fish

[fstbttms]

Anodes are cheap. And considering how important they are to your boat, why anybody would scavenge and use discarded anodes of unknown quality is beyond me.

[groundtackle]

+1 fastb

[Jim Cate]

Originally Posted by fstbttms

Anodes are cheap. And considering how important they are to your boat, why anybody would scavenge and use discarded anodes of unknown quality is beyond me.

Fast, as a substitute for a "zinc fish" supplemental anode, I see no reason to worry about the "unknown quality" of a discarded anode. Depending upon size, the fish cost some 30-60 dollars. To some cruisers, saving that amount is significant.

I would not suggest that anyone not use the proper anode for permanent mounting on their boat.

Jim

[fstbttms]

Originally Posted by Jim Cate

Fast, as a substitute for a "zinc fish" supplemental anode, I see no reason to worry about the "unknown quality" of a discarded anode. I would not suggest that anyone not use the proper anode for permanent mounting on their boat.

What you are suggesting is the use of boatyard detritus as a means of providing corrosion control. In my book, that's a real half-assed solution to a very important problem. But hey, it's your dime.

[Cheechako]

You need to know what is bonded to what on your boat really. If the rudder shaft is bonded you can just attach to some metal that touches that. etc If you have a vibration unit that is urethane /rubber on your engine to prop shaft connection then connecting to the engine wont help.. etc

[Jim Cate]

Originally Posted by fstbttms

What you are suggesting is the use of boatyard detritus as a means of providing corrosion control. In my book, that's a real half-assed solution to a very important problem. But hey, it's your dime.

Actually, I think that relying upon such a supplementary anode is a poor means of corrosion control, no matter what chunk of zinc you hang over the side.

But if that is the means that one employs, I don't see the huge risk that is encountered by using a partially consumed anode that was working just fine on some big power boat but was discarded well before it was used up.

You say "half-assed", I say for a budget constrained cruiser it makes sense. Perhaps, since you have never admitted to owning a boat of any sort (at least in your posts that I have read over the years) you have never felt the need to prioritize where your boat dollars are spent. Many of the members of CF speak of their need to save money where they can. I was making a suggestion of one means of doing so.

Jim

[tkeithlu]

Not a problem. Zincs either bolt on or have steel tabs for welding. If you can weld zinc you have my infinite respect.

[tkeithlu]

Wow! 99% of what you would find lying around a yard is the same alloy of zinc. Only the few (the proud, the deluded) of us who own steel boats use aluminum, and if you can't tell the difference, ask someone who can. Let's not waste what we can recycle and which saves us money in the process.

[Sailmonkey]

Originally Posted by tkeithlu

Wow! 99% of what you would find lying around a yard is the same alloy of zinc. Only the few (the proud, the deluded) of us who own steel boats use aluminum, and if you can't tell the difference, ask someone who can. Let's not waste what we can recycle and which saves us money in the process.

Or those of us in brackish (more on the fresh side).......aluminum anodes that is.

[SteveInMD]

The problem with the fish technique or recycling partially used zincs is that there needs to be a really good electrical connection between the zinc and the metal they are protecting. We are only talking about very small voltages here, which means there is not much power to cut through an iffy connection. A little zinc oxide in the way and the zinc is useless. I'm not trashing the idea of using old zincs, but you need to do it carefully.

[Jim Cate]

Originally Posted by SteveInMD

The problem with the fish technique or recycling partially used zincs is that there needs to be a really good electrical connection between the zinc and the metal they are protecting. We are only talking about very small voltages here, which means there is not much power to cut through an iffy connection. A little zinc oxide in the way and the zinc is useless. I'm not trashing the idea of using old zincs, but you need to do it carefully.

A valid point! I think if I were to employ this method, I'd clean up the old anode with a wire brush, grind a flat, clean area and drill and tap a ~1/4-20 hole into the clean area. I'd then use a cable with a suitable eye terminal to be bolted to the block, using some conductive anti-seize on the threads and under the eye.

A lot of trouble, but IMO would work as well as a new one.

Jim

[Adrenaline]

Originally Posted by tkeithlu

Assumedly your shaft is already part of your bonding that connects engine, rudder, DC ground and the like. Make a good connection to any part of that system, for example cutting off the alligator clip, crimping on a ring connector, and putting it under an engine bolt or battery ground. If your boat is not totally bonded together, then that's a problem in its own right. Check your bonding with some long test leads and your ohm meter to various components in the system, looking for near zero ohms.

This is exactly what I did with a fish, I grounded anything not connected, cut the clamp off and crimped a ring on. Another thing was a added a "ground isolator".

I did this because you never know when your in a marina.

[tkeithlu]

[QUOTE=a64pilot;2260334]It will make the other zincs last longer.
Primary use for my fish is of course I look at it everytime I use the boat, so if it starts getting eaten away I know I have a problem hopefully before I lose my $4,500 prop.

a64pilot, if you're trying to protect a $4,500 (Wow!) propeller might I suggest investment in a silver chloride test electrode (sometimes called a corrosion reference electrode), available from most suppliers of zincs for $125 or so, by which you can keep a log on the effectiveness of your anode system?

[Nightsky]

Originally Posted by tkeithlu

Wow! 99% of what you would find lying around a yard is the same alloy of zinc. Only the few (the proud, the deluded) of us who own steel boats use aluminum, and if you can't tell the difference, ask someone who can. Let's not waste what we can recycle and which saves us money in the process.

Nothing wrong with using aluminum anodes on a steel boat. Aluminum will wear (sacrifice itself) faster than zinc, but will protect as well as zinc provided that it doesn't pacify and that you remember to replace them more frequently than you would zinc anodes.

[senormechanico]

Originally Posted by Adrenaline

This is exactly what I did with a fish, I grounded anything not connected, cut the clamp off and crimped a ring on. Another thing was a added a "ground isolator".

I did this because you never know when your in a marina.

Exactly WHERE is the ground isolator connected? I hope it isn't inline with the extra zinc. That would make the extra zinc completely ineffective.