34' Californian Mystery part #2

So I spent a bunch of time a couple weekends ago just looking around in the Engine room and I found this. It was near a bracket that grounded the propeller shaft (broken) Any ideas what this is/was?

Don't have it on my boat but it looks like a bonding system contact brush for the prop shaft. I use shaft zincs instead.

The items I've circled in red are a shaft brush for bonding system. You can see where it rides in the shaft (also circled). This is an alternative or addition to a zinc in the shaft on the outside. I don't have room for a shaft zinc so have a brush similar to this.

But I think you're talking about the other item - the block that I've circled in orange. My guess is this was some sort of high water alarm sensor mounted on a block of some sort. I see another block on the other side of the shaft galley.

As an aside, bonding wire looks undersized if desire is any lightning protection.

Peter

FlyWright said:

Don't have it on my boat but it looks like a bonding system contact brush for the prop shaft. I use shaft zincs instead.

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So if there are shaft Zincs then I don't need to repair the shaft grounding?

mvweebles said:

The items I've circled in red are a shaft brush for bonding system. You can see where it rides in the shaft (also circled). This is an alternative or addition to a zinc in the shaft on the outside. I don't have room for a shaft zinc so have a brush similar to this.

But I think you're talking about the other item - the block that I've circled in orange. My guess is this was some sort of high water alarm sensor mounted on a block of some sort. I see another block on the other side of the shaft galley.

As an aside, bonding wire looks undersized if desire is any lightning protection.

Peter
View attachment 110868

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My boat definitely has shaft Zincs. Who knows how long the shaft brushes have been broken. The brush on the other side still rubs the shaft, but the wire to it has corroded and broke off, Ha! So if I have Zincs on the shaft, I don't need to repair this and can remove it?

I think it is a good guess about the high water alarm. There is an identical one on the other side as well. I purchased a new high water alarm to install so will probably pull those out as well!

I'll speak for my 43 yr old boat...it's got shaft zincs and never had shaft brushes, as far as I can tell.

FlyWright said:

I'll speak for my 43 yr old boat...it's got shaft zincs and never had shaft brushes, as far as I can tell.

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Same here. Except my boat is a spry 39 years old!

As to whether or not it is needed you can’t say unless you do a test with a silver half cell and see if you have enough anodes without the ground brush. Most likely not needed but I would check to make sure.

Comodave said:

As to whether or not it is needed you can’t say unless you do a test with a silver half cell and see if you have enough anodes without the ground brush. Most likely not needed but I would check to make sure.

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No idea what a silver half cell is. Guess I'll have to go research that!

It is used to tell what the potential of your boat is. Basically to see if you have adequate or too much anodes. This is from boarzincs.com website.

Our Corrosion Reference Electrode is the industry's leading silver/silver-chloride (Ag/AgCl) reference electrode for performing corrosion potential surveys on boats, yachts and docks. This is a professional-grade tool housed in high impact ABS Corrosion Reference Electrode and User's Guide
by ABYC-Certified Corrosion Expertsplastic that includes additional weight for controlled submergence, and attached by 25 feet of marine grade copper cable.

The Corrosion Reference Electrode is an extremely useful test and diagnostic tool that should be included within the toolbox of every boater and marina operator. When plugged into your digital multimeter you get answers to questions such as:

"Do I have enough zinc on my boat?"
"Are my shaft zincs still attached?"
"Is my bonding system working okay?"
"Are boats next to me eating my zincs?"
"Is my galvanic isolator working?"
"Is all of my electrical equipment installed correctly?"
"Do I have stray electrical currents either in my boat or at my dock?"
"Is my dock and/or marina operating at the correct corrosion potential?"

So, I was searching Google for what the Synchronizer that was installed on my Californian was used for led me back to the Trawler Forum here and forum member TG's post about the Telcor Synchronizer Model 166 . He posted the user's manual for this and BAM inside the user manual was a drawing of a shaft rotation sensor that looked remarkably like the small mystery part in the pictures above. Yay for knowledge! Yay for another thing to see if I can fix!

DBoat said:

So, I was searching Google for what the Synchronizer that was installed on my Californian was used for led me back to the Trawler Forum here and forum member TG's post about the Telcor Synchronizer Model 166 . He posted the user's manual for this and BAM inside the user manual was a drawing of a shaft rotation sensor that looked remarkably like the small mystery part in the pictures above. Yay for knowledge! Yay for another thing to see if I can fix!

Click to expand...

I have the same system with the same sensor on a similar bracket. The the shaft mounted portion of the synchronizer is long gone before I bought the boat. I assume it was just a magnet on a hose clamp. I'll be converting to digital gauges so I am removing it.