Odd Anode deterioration

[TheOrs]

Some light reading:

The Boatowner's Guide to Corrosion

Everett Collier

ISBN13 9780071475440

https://www.bookdepository.com/Boat...ent=order-details&utm_campaign=Order-dispatch

I bought three different books on marine corrosion. The above was what looked to be the most 'D.I.Y' or least technical but after reading all three I found it to be the easiest to read and also the most in depth treatment of the subject. Very interesting read (if you like that sort of thing). It won't answer your question though...

 

[jon and michie]

Ok, I had the same on mine and the SS props are specced to be electrically isolated from the rest of the drive which happens between the hub and the prop, there are some plastics that goes between the cone and the prop as well to keep it isolated.
Over time stuff gets in there and creates a connection or for me the prop repair man did not understand this so after the refurb I got the same on one of them.
If this is your problem there is an easy test and that is to ohm meter between the hub and prop and sometimes it will help cleaning around the hub and making sure the ring sitting there don't touch the prop. With the props on the drive you can easure between the drive and the prop blades.
Interestingly I did the same as you beefing up with lots of anodes and after a few years I learned about this, fixed the props and suddenly the anodes lasted a lot longer.

Thank you for sharing your experience this could be a big help
I will look at mine and test out -funnily you mention the cone which bolts up last as I don't recall any sort of washer between the cone and prop.
jon

 

[jon and michie]

I am happy to just beach the boat mid season just before the low water slack and quickly change the ring anode.

Thanks BruceK - I bet that was fun the first time you did it

jon

 

[BruceK]

Thanks BruceK - I bet that was fun the first time you did it

jon

We are blessed with a very soft sandy beach (ankle deep when you walk) just 200 yards from the mooring if you dont want to wait an entire tide cycle at the drying wall. Makes it very easy and safe and it's a great place to picnic while you work too

 

[BruceK]

The local Volvo dealer recommended these to me. I have a Mercruiser system from OEM on my boat but have no idea if mine are working or not. Dont know how good these Volvo equivalents are. Might be worth putting to the board to see if they are effective?

 

[Sailorsam101]

I've not seen you mention how you moor up? Stbd or port side to and what to?

I used to be at deacons on the Hamble..port side to stern in but with a very large steel pile very near to my stbd stern quarter. I had just the wear you had on my Stbd outdrive anodes.

I've moved to eastlands and it's not happened again. Do you have anything large near you stern?

 

[TheOrs]

I have a Mercruiser system from OEM on my boat...

I have the MerCathode system also. Mine wasn't working; made a huge difference when I fixed it.

 

[BruceK]

I have the MerCathode system also. Mine wasn't working; made a huge difference when I fixed it.

Do you have an instruction manual for it? I dont even know if mine is broken, on, off or what. It doesn't help that to access it I have to strip the engines down for access but as I am doing that this season I may as well get in there and have a gander.

 

[TheOrs]

Do you have an instruction manual for it? I dont even know if mine is broken, on, off or what. It doesn't help that to access it I have to strip the engines down for access but as I am doing that this season I may as well get in there and have a gander.

Kind of. I have 'Mercruiser Service Manual no. 11 - Section 7A - Corrosion Protection' in .pdf form, which contains trouble-shooting advice for the MerCathode. To fully troubleshoot you need the Reference Tester 76675A1. I bought one (about £100 from the USA) because it was worth it to me but you can do a lot of troubleshooting without it.

I can't see any way to attach something to a PM but you could PM your email address or http://www.boatfix.com/merc/Servmanl/11/11a7r5x.pdf...

 

[BruceK]

Got it thank you. Mine is a earlier or at least a different version. Hopefully it will be largely similar in operation

 

[TheOrs]

Got it thank you. Mine is a earlier or at least a different version. Hopefully it will be largely similar in operation

View attachment 74716

Your type is transom mount. The other type mounts in the leg itself but obviously that's only going to work if you have a Mercruiser leg. The service manual covers transom mount: page 7A-20.

 

[jon and michie]

I've not seen you mention how you moor up? Stbd or port side to and what to?

I used to be at deacons on the Hamble..port side to stern in but with a very large steel pile very near to my stbd stern quarter. I had just the wear you had on my Stbd outdrive anodes.

I've moved to eastlands and it's not happened again. Do you have anything large near you stern?

Hi Sailorsam - I moor up next to my finger which would be starboard fwd the same as I have done last season the nearest pile is on my port fwd and a distance Away.
Jon

 

[jon and michie]

BruceK - I am not sure if volvo discontinued that protection box
Jon

 

[BruceK]

My local Volvo dealer was trying to flog it to me a couple weeks ago and its on marinepartseurope.com for less than a full compliment of annodes so I guess its still about.