Keith-i
Well-known member
In an attempt to reduce corrosion on my ‘bronze’ rudder I am proposing installing a small anode. Is there any advice as to where it should go? Top, middle or bottom? This is on a semi-d Channel Island 32’ motor boat.
Where to fit rudder anode?
- Thread starter Keith-i
- Start date
Jamie Dundee
Well-known member
Mine’s at the top, don’t know if it makes any difference.
Tranona
Well-known member
Why do you think you need an anode? What other metal is directly attached to it under water? Bronze is usually chosen for a rudder because it does not corrode on its own so does not need an anode. Have you experienced corrosion in the past?
Keith-i
Well-known member
Because it seems to be going a bit pink! Perhaps it is some form of brass rather than bronze, but the patches of pink have expanded over the last 10 years. I did have it bonded to the main hull anode but someone suggested a dedicated anode on the prop may help.
Tranona
Well-known member
Is the rudder stock stainless? If so then bond your hull anode to the stock. Have you "rung" the blade? if it sounds dull then it has dezincified, but that may be because it is a brass. However, that surface pink may not be a problem. Usually serious dezincification shows as crumbling on the edges and that does not seem to be the case. If that pink has taken 10 years to show doubt it is serious.
Personally if it is sound, I would clean it up and paint it with Velox following the instructions here antifoulingpaint.net Not only will this give you semi permanent antifoul, but will reduce (in fact eliminate) the exposure of the metal to seawater. Many who have used Velox on bronze folding propellers have reported significant increases in life of anodes.
Personally if it is sound, I would clean it up and paint it with Velox following the instructions here antifoulingpaint.net Not only will this give you semi permanent antifoul, but will reduce (in fact eliminate) the exposure of the metal to seawater. Many who have used Velox on bronze folding propellers have reported significant increases in life of anodes.
vyv_cox
Well-known member
I doubt very much that the alloy is bronze, the colour is wrong. You can find a guide as to the identification of copper alloys by colour on my website under Brass and Bronze. Bronze is known in USA as 'red brass'.
A zinc anode will not prevent dezincification. Zinc cannot protect zinc, which is what you are asking it to do. As suggested, painting it is by far the best protection. Hammerite Special Metals primer is excellent on brass, followed by whatever antifouling paint you prefer.
Keith-i
Well-known member
No, it is the same material as the balde.
Thanks Vyv, very informative and obvious when you think about it. I will paint it. Incidentally I did take a look at your excellent website.