Shaft Anode Replacement

[TexSail]

This evening, I am planning on installing a new propeller shaft anode on my Hunter 33. It is in fresh water, so I am using a magnesium anode. I have already measured it and gotten an anode to fit (1"). It fits around the shaft in two parts and attaches with SS screws w/ hex heads.

1) Is it OK to leave the old anode on there?

2) Any tricks of the trade you could share (I am tying the allen wrench to my wrist with a string) to prevent dropping some parts?

Thanks.

[Blue Stocking]

I guess from your wrist tie comment that you are doing this change with the boat afloat.
I shudder whenever a hear this after almost losing a diver friend to electrocution in a marina.
Make sure that everything electrical is shut down and isolated. No shore current connection, no inverter, no battery charger.
1/2 Volt DC can cause diaphram spasm and drowning.
I may get lambasted for this post, but I want you alive for a long time.

[TexSail]

Thanks for the concern Blue Stocking. I intend to unhook all of the shore power and shut off the DC panel and inverter.

[Healer52]

Originally Posted by TexSail

This evening, I am planning on installing a new propeller shaft anode on my Hunter 33. It is in fresh water, so I am using a magnesium anode. I have already measured it and gotten an anode to fit (1"). It fits around the shaft in two parts and attaches with SS screws w/ hex heads.

1) Is it OK to leave the old anode on there?

2) Any tricks of the trade you could share (I am tying the allen wrench to my wrist with a string) to prevent dropping some parts?

Thanks.

If you have room for the old one, put two new ones on and that way you won't have to do it as often

[Hudson Force]

I have free-dived for this application, but I do choose to do this away from the marina. Stray currents in marinas can be deadly even if all on your boat is shut down. If you have space, you might wan't to practice fitting the zinc on your shaft in front of the stuffing box while holding your breath. You may want to loosely attach the zinc and then take a heavy bar down to tap the zinc with tightening to insure a good contact with the shaft. I don't like to dive with tools tied to my wrist without an easy release. There's not good in finding yourself tied to line that is snagged to the bottom of your boat! Take care and joy, Aythya crew

[Bash]

As far as tips, I always take a wire brush with me to clean the shaft before I attach the anode. I usually install a new anode and leave the old one on, but only if it's got enough mass left that I'm certain the shaft won't throw it while underway. They make quite the clunk if you leave them on too long.

[rebel heart]

Scuba diving it is a hell of a lot easier than free diving, at least on mine. I have maybe 1/8" clearance between the anode and the hull. Not the kind of thing you want to "sort of" be okay.

I keep a fine mesh ditty bag clipped to my bc when I'm down there to hold my parts and tools. Small enough mesh that the tiniest part you're working with won't go through it. The bottom is here ultrafine silt. Impossible to find anything that gets dropped.

You're not going to get electrocuted. It's a real risk in freshwater, much less so in salt (the salt water itself is much more conductive than you are). If you want to be sure, just unplug the shore power before you start. One of the guys I get a lot of scuba advice from is a bottom diver up in SF and won't dive a boat unless he can yank the shower power in advance.

[TexSail]

I got it done and I'm still here. The power was unplugged. Thanks for the advice everyone.

[redmirage]

One trick I have used is to take some sewing thread and tie the bolts in place to keep from droping them. Just use a little, it is not thick enought to stop the zinc from being tightened on the shaft. Also make sure the shaft is good and clean, you can use some wet or dry sand paper to clean it so your zinc will make good contact with the shaft.

Charles