Anode studs

[Jokani]

I tried to replace an anode yesterday:

Without out too much pressure applied to the nut, the stud started to rotate.

I checked the stud on the other side:

I'm surprised that the studs are only secured sealant, washers and nut, is that the norm? I can see why the stud turns easily, I should have checked this first, but in my naivety, thought it 2 minute job removing two nuts

As the stud turns, do I need to replace the existing studs? What is the best way forward?

PS. Yep, anti-fouling and bilge cleaning are on the list, just saving the fun jobs until last ;-)

 

[VicS]

I tried to replace an anode yesterday:



Without out too much pressure applied to the nut, the stud started to rotate.

I checked the stud on the other side:



I'm surprised that the studs are only secured sealant, washers and nut, is that the norm? I can see why the stud turns easily, I should have checked this first, but in my naivety, thought it 2 minute job removing two nuts

As the stud turns, do I need to replace the existing studs? What is the best way forward?

PS. Yep, anti-fouling and bilge cleaning are on the list, just saving the fun jobs until last ;-)

Are they the correct type of studs

http://www.mgduff.co.uk/mgduff-product-catalog/Ancillaries/Ancillary+Item+Studs/

Should have integral flange on the outside and be secured to the hull with nuts and lock nuts inside (Sealed in hull of course)

Andes then fit separately outside with own nuts

http://www.mgduff.co.uk/leisure-craft/fitting-instructions/fitting-bonding.html


Looking at the photo I think I'd fit new studs. They will certainly need resealing if they turn
Dont forget the backing pads.

.

 

[NormanS]

Looking at the photo, I would say that there's lots of life left in that anode.

 

[VicS]

Looking at the photo, I would say that there's lots of life left in that anode.

Looks like its been antifouled

 

[vyv_cox]

Looking at the photo, I would say that there's lots of life left in that anode.

Cannot say as much for the electrical connection though

 

[RichardS]

Looks like its been antifouled

It's a great way to make your anodes last! :encouragement:

(joke)

Richard

 

[Len Ingalls]

What is the purpose of a zinc on a grp hull? Not bolted to any underwater metal,what does it protect.
Since it has a small wire conn. to it,it appears to be used as a ground plate?
Just wondering. Thanks/Len

 

[vyv_cox]

What is the purpose of a zinc on a grp hull? Not bolted to any underwater metal,what does it protect.
Since it has a small wire conn. to it,it appears to be used as a ground plate?
Just wondering. Thanks/Len

In some cases it protects the stern gear, assuming an electrical connection through the shaft coupling, which in this case appears to be a solid one. However, it would appear that the anode cannot 'see' the prop so is probably not doing a lot.

 

[Sinbad1951]

If it were my boat this is what I would do. Remove or grind off the external nuts beside the anode. Using a hammer and drift knock the bolts through to the inside of the hull. (They are badly corroded internally so knocking them from the inside may distort the hole drilled thru the hull) Next purchase new McDuff anode fixing bolts and replace the bolts having cleaned out the holes and used new sealant. Replace the old anode on the studs as it has lots of life.
Once you have tidied the mess up you need to attach a wire from the inside of one of the studs to your prop shaft. Yes the shaft! This is easily done by purchasing a brush which runs on the shaft and is wired back to the anode.
The end result is a direct electrical connection between the anode/shaft/prop.

 

[NormanS]

If it were my boat this is what I would do. Remove or grind off the external nuts beside the anode. Using a hammer and drift knock the bolts through to the inside of the hull. (They are badly corroded internally so knocking them from the inside may distort the hole drilled thru the hull) .

That won't work if they are the proper anode studs, which have a square flange on them, on the outside of the hull.

 

[Jokani]

I have new studs on order, I'll remove the old (some how) and see if I can make a proper job of it.

This was also an interesting read http://www.ybw.com/forums/showthread.php?196097-Anyone-using-a-prop-shaft-brush-for-anode-connection

 

[Billjratt]

I've just spent an interesting couple of days with a stud that wasn't there. http://www.bluemoment.com/forum/viewtopic.php?f=3&t=9132