Rudder Post Grounding

[drh1965]

On my boat, I noticed that the PO disconnected the ground wire from the rudderpost. I assume this was to avoid stray currents from surrounding boats eating anything but the rudder post. Is this common practice?

[knottybuoyz]

There are two basic philosophies, the "bonders" and the "isolationists". We're more than likely going to be able to settle the age old question of which is better, a mono-hull or a multi-hull sailboat before we answer that question.

My personal view? If the mfgr bonded the underwater hardware and a PO removed it, I'd put it back the way the mfgr designed and built it. IMHO

[David M]

So long as the stainless steel on the post is getting an adequate supply of oxygenated seawater to the metal, it should not go "active". My question is, what could the post possibly react with?

[Alan Wheeler]

My question is, what could the post possibly react with?

What are the bearing materials? What is the stearing mechanism and how is it connected or isolated from the Rudder/rest of the boat?

[DWT]

Any metal on your boat that is in the water should be bonded(wired together) to a sacrificial zinc.
Boy, I started something now!
David
69Morgan 30’
CarolAnn

[drh1965]

Originally Posted by Alan Wheeler

What are the bearing materials? What is the stearing mechanism and how is it connected or isolated from the Rudder/rest of the boat?

I really don't know.

[drh1965]

It sounds like there is no "cut and dried" answer to this question. I wonder if there is a way to retrofit a zinc on to the rudder post?

[knottybuoyz]

No there probably isn't a definitive answer. What I'd do is bond the post with a coiled 8ga (green) tinned marine wire to the vessels bonding system. This way your existing sacraficial zinc anode will do the work. If you choose to leave the rudder post isolated then you'll have to add another zinc anode. As to fitting a zinc to the existing rudder post, well you'd have to provide pics to see if there's room for one.

[David M]

I would just call a naval architect or a good boat yard and find out what most other boats of a similar configuration do.

[fastcat435]

Never ground your rudder stock to anything at all if you can avoid it My personal experience learned me that and it was a costly experience .
The Jefa Aluminium 6083 rudder stocks just eat away when grounded and if not they do not even show any corrosion at all.
We now insulate the Aluminium posts with basalt and epoxy from the salt water and they are anodized on top of that so even the stocks are insulated from salt water now.
I am sure the previous owner found out the same as me and took away the grounding
Greetings

Gideon

[donradcliffe]

Gideon,

I was surprised to hear that you are using aluminum rudder posts! Based on past problems like BoatUS.com: Boat Reviews by Jack Hornor, N.A. - Pearson 30, I would run, not walk away from a boat with an aluminum post.

Knowing that you are trying to save weight, I understand why you dont use stainless steel, but why did you chose aluminum over carbon fiber or fiberglass??

[fastcat435]

Originally Posted by donradcliffe

Gideon,

I was surprised to hear that you are using aluminum rudder posts! Based on past problems like BoatUS.com: Boat Reviews by Jack Hornor, N.A. - Pearson 30, I would run, not walk away from a boat with an aluminum post.

Knowing that you are trying to save weight, I understand why you dont use stainless steel, but why did you chose aluminum over carbon fiber or fiberglass??

It is all a matter of cost and chord thickness not to go carbon anymore
We did on hull number one and now these would cost us 6000 euro each in carbon fiber and that is just for the stocks without bearings and rudders
We have tested the solid aluminum 6083 stocks and they are as good as new after 3 years. With the Carbon stocks the chord thicknes was 50 % more so that gave us extra resistance .
Until something better comes along we will have to go this route

Greetings

[drh1965]

Interesting comments. I noticed that the aluminum steering pedestal was corroded and requires cleanup and paint. Is the rudder post isolated from the steering pedestal on most boats? I wonder if that is why one of the POs disconnected the ground?