[Amel Yacht Owners] Re: Prop Shaft Electrolysis

Kent Robertson

Thanks Gary,
The pic will be of some help, I'm sure.  I've got a request in to Maud at Amel for help with the repairs.

Joel called me today, as always very helpful and a vast reservoir of all things Amel.  He suggested that the entire C drive should probably be replaced, since what ever caused the prop shaft corrosion would be electrically connected to the rest of the drive.
When the input shaft to the CDrive broke, there was nothing to suggest that galvanic corrosion was involved.

I have a LOT to learn on the subject...as in why didn't it destroy the brass prop before the stainless shaft????
In over my head ...again
Thanks again for your concern and suggestions.

On Mar 29, 2014, at 10:03 AM, amelliahona <no_reply@...> wrote:


Dear Kent:

I too am shocked at the state of  your prop shaft.  I looked for the diagram of the C-drive in my files, as I too have seen a drawing of it recently, but I can't find it.  Here is a link to a photo of the C-drive (I think you may have posted it) if that will help. 
 It appears there is access to the shaft and bearings of the C-drive from the forward end but probably this is glassed in and I am not sure how you remove the C-drive housing.  I think you are going to need to have a serious discussion with Amel as to how to proceed.  I will continue to look thru the photos and files sections of this forum as I am pretty sure the diagram is on this forum somewhere. 

As for zincs, mine last about two seasons (only in the water for 6 months at a time due to hurricane haul out annually.  Whenever I leave the boat in a marina I DO NOT leave it plugged in to shore power.  I have the caretaker plug it in once a month for 6 hours to really top up the batteries, but otherwise depend on some small solar panels to keep the batteries trickle charged.

One time I asked Amel why they used the red plastic cap on the auto prop rather than placing a zinc there.  Their reply was that it was un-necessary and that you can "over-zinc" the boat.  I wasn't really sure as to the logic behind either of those answers but seeing as they were the experts and I was the novice I didn't press for more details.

I wish you the best.

Gary Silver
s/v Liahona   currently at Jolly Harbor