Bonding skin fittings

[ghostlymoron]

I know that this has been discussed before on this forum but I can't find it using the search facility. The question is should one bond skin fittings to the anode?

 

[Tranona]

If the pipes are non metallic, then no bonding is required as they are not in contact with any other metal. Make sure they are DZR or bronze (or plastic) if you are replacing them.

 

[Kelpie]

+1
No need to bond as all you are doing is connecting dissimilar metals.
I found ASAP Supplies very helpful in getting me sorted out with the right materials when I replaced all the through-hulls, valves, and tails.

 

[vyv_cox]

There is a fascinating and totally opposed point of view on this subject between USA and Europe, even though the norm for USA fittings seems to be bronze, not a modified brass. Every USA source of information and the ABYC advocate bonding throughout, whereas on this side of the Atlantic we say just the opposite, as Tranona and Manavier say. I have looked into this at some length and conclude that the USA advice is based mainly on an intention to dissipate lightning strikes and has nothing to do with corrosion.

There have been quite a few examples of serious corrosion caused by bonding of seacocks, in which one becomes anodic relative to the other. It might be thought that having an anode connected to the bonding circuit would prevent this, but if the anode is somewhere astern as is often the case it cannot 'see' skin fittings forward and its effect is not felt.

 

[jwilson]

The bonding/not bonding skin fittings is a constant source of discussion/argument. As a broker i see quite a few surveys. Some UK surveyors will report that skin fittings are not bonded and should be. The owner will then argue strongly that the surveyor is wrong. The buyer says his surveyor must be right: he is the expert.

You could be right about the lighting issue in USA. More there than here, particularly in the south. Perhaps the US favouring bonding is also because so many US boats are in marinas on shorepower, and many are also in fresh water lakes - does that make a difference?

 

[prv]

Perhaps the US favouring bonding is also because so many US boats are in marinas on shorepower

I'd say that's pretty common here too, at least in this part of the country.

Pete

 

[nigelmercier]

Some UK surveyors will report that skin fittings are not bonded and should be...

Time to find a new surveyor then.

 

[Keith-i]

I completely follow the logic about not bonding isolated bronze (or other resistant) fittings to the anode, but thinking of my boat with a bronze rudder I wonder whether I need an anode at all? The shaft has it's own and I can't think of any other underwater metal which would need protecting. Currently my rudder and engine water intake fitting are bonded which are also therefore connected to dc negative and the engine.

 

[macd]

The only trouble with that reasoning, Keith, is that many (probably most) so-called bronzes used on boat fittings are actually modified brass -- hence anodes on "bronze" propellors, which if they were true bronze would not need them.

 

[jwilson]

Time to find a new surveyor then.

As brokers we don't choose the surveyor - that is entirely up to the buyers, and few have much to go on when choosing one. All we do is provide a long list subdivided by area showing just about every Uk based marine surveyor. We will absolutely not recommend a surveyor. There is just one surveyor we won't put on our list - but not for reasons of anodes/bonding etc.

 

[oldsaltoz]

TIP:

To search the forums use Googlr or other engines, just start with the following: ybw.com/forums

If you type:-

ybw.com/forums/bond skin fittings

You get:
https://www.google.com.au/search?q=...hannel=sb&gfe_rd=cr&ei=SCnVU7WGFKeN8QegxIHoCQ


Good luck and fair winds.