Peter Birkett
2019-07-21T14:29:14Z
Hi everyone,

I am in my second season with Blakeney Seal - P325/20 - and, having moved up from the much simpler 235, am now getting to grips with some of the finer details. The user manual for my P325 contains an updated diagram of the keel assembly (see picture) dated June 1995. The only difference from the original diagram is a sacrificial anode which seems to be suspended by a copper wire attached to the keel lock up pin plates. The sacrificial anode itself is shown sitting just above the lower end of the hydraulic ram. In spite of the diagram, this does not seem to have been fitted on Blakeney Seal. Does anyone else have an arrangement like this? If so, does it help avoid corrosion at the lower end of the hydraulic ram?

Peter Birkett
P325/20
Blakeney Seal

Keel diagram.jpg

Click to View Image66 View(s)

johniow
2019-07-25T21:15:44Z
Hello Peter, I think every 325 has slight variations. Nosey 325-26 has an anode on the collar of the ram (picture to follow) but no wing anodes that I've seen! Suspending an anode seems a better idea than having to withdraw the ram to inspect and replace it.
Have a look at
http://www.parkerseal.or...s/modsmaint/p325ram.aspx 
Nosey - Parker 325-26
johniow
2019-07-25T21:53:48Z
And here's some pictures from when I had to replace the ram ..
Old ram with anode at bottom end.
Keel_ram_bottomend_features.jpg

Click to View Image46 View(s)


New ram awaiting anode.
Keel_RamsOldnNewAnode.jpg

Click to View Image49 View(s)


Nosey - Parker 325-26
Mike Lockwood
2019-07-28T16:59:52Z
Yes, we have a ram anode but still got startling corrosion on the exterior stainless steel upright part of the keel. We change our ram anode every other winter.

However, we inserted a stainless steel bolt through the deck hatch above the keel, connected this to the top of the keel with a coiled wire.

When not sailing, we connect the deck end of the bolt to an over-the-side anode (an old hull anode usually).

We measured a 0.5V potential between the keel and the over-the-side anode. Some battery!

Extracting the ram is not the easiest job but is essential. Three pairs of hands make it a little easier.

We also keep the keel up when on our mooring.

We also have disk anodes on the wings of the skeg and we found we had to connect one of these to the metalwork surrounding the prop shaft, initially with a wire, latterly with a stainless steel plate.

Also, a hull anode connected through to the shaft inside the boat with brushes.

No problems since we did this!

Hope this helps.

Mike Lockwood
Lucky Devil
Mike Lockwood
Lucky Devil
Parker 325/35
Peter Birkett
2019-08-24T10:47:49Z
Thanks John and Mike for your helpful comments. I have a hull anode on Blakeney Seal and hub anodes on the prop and bow thruster but nothing on the keel unless there is a ram anode fitted. I have not yet ventured to take out the hydraulic ram but this will undoubtedly be necessary in due course. In the meantime, the dangling anode whether alongside the ram or just over the side seems a sensible precaution. I will also try measuring the potential difference between the keel and the anode as 0.5V seems quite a lot!

Peter Birkett
Blakeney Seal P325/20
MartinH
2019-09-29T16:55:08Z
It's worth being aware that the partially enclosed "box" in the stainless fabrication of the keel which surrounds the lower end of the ram can fill up with silt. If this happens the anode becomes buried and ineffective. Making sure this is well washed out each time the ram is removed (most winters) seems to have kept us out of trouble with electrolytic corrosion.

Martin Hargreaves
Tringa 335/50