loch mooring antifoul and anodes

ColleyV8

ColleyV8

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About to organise a mooring for my colvic 20, it is going in loch etive, its mostly freshwater with some salt coming in later in the year.

I need to get the boat anti fouled and new anodes fitted ready, is there any specific type (antifoul and anodes) for the location?

I have two rudder anodes, a large one on the hull bonded to the engine and one on the skeg, its powered by a VP MD11ç, are there any inside the coolant system?

Regards
 
I have heard, anecdotally, that Micron 66 is not so, or not at all, effective in fresh water - even though it is superb in salt water. But it is also one of the most expensive AFs. Why is would not work in fresh water I have no idea.

I cannot help with anodes and I'm not that much help with AF either.

Jonathan
 
John, that's something I'm learning about boats with metal bits in the water. I bought the boat like that, presumably to protect the shaft and prop as they have no anodes.
 
The anode that is most effective in both salt and fresh water is Aluminium. Magnesium is good if only fresh but will disappear quickly in salt, Zinc will become inactive very quickly in fresh water. My boat is moored in fresh water but we sail at sea. I have a Al hull & shaft anodes but use a hanging Mg anode when berthed in fresh water. Used this regime fror 6 years with boat afloat all year round and it works fine.

As for an AF, the one that works for me is Jotun Seaforce although it is difficult to get now.
 
Magnesium anodes may need to be replaced about every 4-6 weeks in Loch Etive unless you do not go out to sea much, I think it should be salty enough to use zinc but aluminium is probably the best compromise. Our boat is in fresh water about 12 weeks venturing to sea for as similar time broken in to some day sails and 3 or 4 3-4 week cruises. We use zinc (saildrive, so aluminium not available) supplemented by a zinc hanging anode which we clean the passivated coating off about every three weeks. Zinc shaft and prop anodes are self cleaning if the engine is used enough. In the fresh water of the Canal some boats with ss shafts and bronze props seem to get without any anodes at all.
For antifouling I used Shogun which was good but now use the cheap Flag sold by Gael Force as their own brand, it keeps the hull clean but loses its dark blue colour very rapidly but our boat come out for nearly 6 months every winter, (because the prop anodes would not last a year) if you are able to stay in for two years I would recommend Shogun.
 
ColleyV8 said:
About to organise a mooring for my colvic 20, it is going in loch etive, its mostly freshwater with some salt coming in later in the year.

I need to get the boat anti fouled and new anodes fitted ready, is there any specific type (antifoul and anodes) for the location?

I have two rudder anodes, a large one on the hull bonded to the engine and one on the skeg, its powered by a VP MD11ç, are there any inside the coolant system?

Regards
Click to expand...

I too would suggest aluminium anodes for the reasons already given together with hanging magnesium anodes if necessary in fresh water but they must be electrically connected to the items they are to protect.

I'd suggest a good paint system should be the primary protection for the rudder.

The hull anode connected to the engine is there to protect the stern prop and shaft. It must be near to them and there must be a good electrical connection which will involve bridging any flexible shaft coupling there may be.

Don't know what the skeg anode is for unless the skeg is steel and it is there to protect that. If so a good paint system should be the primary protection for that as well

There are no internal anodes in an MD11C
 
DSC00505_zpscqhalwbv.jpg


This the structure, will order the aluminium anodes. The entire skeg is steel, the rudder looked like stainless , I have wire brushed and sanded the metal work and given it a coat of Internationals primocon, I was going to antifoul over that.

The two anodes fasten to the rudder where no have left the primer, the skeg one fixes where the small hole is under the rudder

Will have to research hanging anodes. Thanks for the all the advice.
 
Re hanging anodes, you can buy specially made ones but what I have done is to buy a narrow boat anode like this:

View attachment 42223

http://www.ebay.co.uk/itm/Magnesium...-cruiser-/251345367154?_trksid=p2054897.l5658

I cut it in half and connect the end to a wire that then connects externally to a stud that passes through the transom. This is in turn attached internally to the hull anode connection and so to other things being protected. At the end of the year, the surface will be very rough and pitted. At this point I replace it with the other half. The pitted one can then be filed down to clean smooth metal ready for use again in the future. I reckon that one of these anodes used in this way should last for several years.
 
Every boat appears to react differently. Like you, I read lots and spoke to lots of people when we moved a Jeanneau SO into the Crinan Canal. I bought a magnesium anode to suspend on a wire when in the canal. 9 years later, I have still to use the magnesium one. It gets lifted every three years and the standard zink shaft anode (only one used) is replaced with about two thirds used. As for anti fouling, I use cheapest Seagoing crushing which lasts three years and comes out as clean as it went in with w tiny amount of slime at the water line. Best thing is to speak to local boat owners and see what alchemy they use!
 
I did some experimental work in Loch Etive a few years ago and measured the salinity. it came out about 28,000ppm, and that was above the narrows at Bon Awe/Taynult. Seawater is nominally 35,000ppm, so it may be more saline than you think, although the surface layers may well be less saline during periods of high rain fall.
 
I must admit, anode type is something I haven't considered when mooring my steel ketch in Airds Bay, Taynuilt, from later this month. I think the zinc ones should be okay - the tidal limit is way further up the loch and rainfall will only have a temporary effect.
Ian
 
ColleyV8 said:
Going to talk to owners already there as suggested, Ian, are you one of the new moorings the committee mentioned?
Click to expand...

Yes. North West Marine were up on friday laying mine and a couple of other moorings. Next job is a trip up from Ardfern and scrape under Connel bridge at slack water on a neap tide. That can wait until a nice warm sunny day as its a 5-6hour trip: hopefully we'll get some in about 2 weeks. Dugie from the ABMA said they only had a couple of moorings left when I applied so if you haven't got one sorted, don't delay.
Ian
 
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