hoppy1959
New Member
is there any way to check wear without having to use diver or lift boat out of water <span style="color:red"> </span>
anodes worn out is there any way to check
- Thread starter hoppy1959
- Start date
TheBoatman
Well-Known Member
Not that I know of. But experience should give you a guide ~ record when you fitted them new and when did they wear out.
Sorry if the post seems simplistic but IMHO it's what we all do.
Peter.
Sorry if the post seems simplistic but IMHO it's what we all do.
Peter.
damo
Well-Known Member
Borrow an underwater camera. Seriously - it's what a local marine engineer uses to inspect below the waterline.
One problem with anodes is that they may have developed a surface crust, which will crumble off when scrubbed or pressure-washed. Until then it may appear that they have had little erosion.
Others may disagree, but if they have been in the water for a year or so (and are working) it is time to change them IMO. If they are in good nick after that time they are probably not working. Depends on your boat of course, and where it is kept, but I think the above is true especially in a marina berth.
One problem with anodes is that they may have developed a surface crust, which will crumble off when scrubbed or pressure-washed. Until then it may appear that they have had little erosion.
Others may disagree, but if they have been in the water for a year or so (and are working) it is time to change them IMO. If they are in good nick after that time they are probably not working. Depends on your boat of course, and where it is kept, but I think the above is true especially in a marina berth.
colinroybarrett
Well-Known Member
No.
You may be able to rig up a complicated voltmeter/resistance checking system, but only if you have a GRP hull and separate cabling to each anode. You would have to take a benchmark voltage/resistance reading whilst all anodes were new and then regularly check this over time. I think megabucks would be needed to keep such a ‘database’ up to date.
Or do you know a diver who works for ‘sixpence’?
Just lift the boat out each year, or every two to three years in fresh water and compare size/corrosion effects against new ones, probably much cheaper in the long run.
In any case, surely we should check the underwater profile of our boats at least as regularly as this as a matter of safety?
CRB
You may be able to rig up a complicated voltmeter/resistance checking system, but only if you have a GRP hull and separate cabling to each anode. You would have to take a benchmark voltage/resistance reading whilst all anodes were new and then regularly check this over time. I think megabucks would be needed to keep such a ‘database’ up to date.
Or do you know a diver who works for ‘sixpence’?
Just lift the boat out each year, or every two to three years in fresh water and compare size/corrosion effects against new ones, probably much cheaper in the long run.
In any case, surely we should check the underwater profile of our boats at least as regularly as this as a matter of safety?
CRB
hoppy1959
New Member
thanks but im new to boating but have heard that if you dont know the marina or you have differant boats nearby that this can affect the time your anodes last and put your metal items at risk
Richard10002
Well-Known Member
[ QUOTE ]
Not that I know of. But experience should give you a guide ~ record when you fitted them new and when did they wear out.
Sorry if the post seems simplistic but IMHO it's what we all do.
Peter.
[/ QUOTE ]
Simplistic, but would take a few years to build up records.
with flippers, mask and snorkel, if you are reasonably fit, you can at least have a look at the anode for a few seconds. It may even be possible to wire brush it, over a few dives, to clear the crust.
Scuba diving is the best way, but you need to be fairly experienced to be both comfortable doing it, and aware of the risks of shallow diving, under a boat.
Of course, if you haul out annually, you would hope that would be fine.
Not that I know of. But experience should give you a guide ~ record when you fitted them new and when did they wear out.
Sorry if the post seems simplistic but IMHO it's what we all do.
Peter.
[/ QUOTE ]
Simplistic, but would take a few years to build up records.
with flippers, mask and snorkel, if you are reasonably fit, you can at least have a look at the anode for a few seconds. It may even be possible to wire brush it, over a few dives, to clear the crust.
Scuba diving is the best way, but you need to be fairly experienced to be both comfortable doing it, and aware of the risks of shallow diving, under a boat.
Of course, if you haul out annually, you would hope that would be fine.
Richard10002
Well-Known Member
Should have read the question!!! I cant think of another way.
colinroybarrett
Well-Known Member
Sorry ‘Hoppy’
Didn’t realise you were new to the forum – Welcome – Anodic corrosion is a very complex science and, as you so rightly say can be a huge problem in a marina, however my experience, over 25years of boating is that it not as big an issue as you may be led to believe.
With a GRP hull, you just need to ensure that internally the ‘bonding’ that is the cable from anodes to engine to skin fittings etc are really very ‘sound’ and making good contact with each other. There really is no common ground point, to tie them to, but the engine casing is as good as anything.
On a steel hull bonding is not an issue, provided the anodes are properly bolted to welded points on the hull and ‘visible’ to ‘dissimilar metals’ i.e. the prop and its shaft etc.
In a marina, we tend to ‘worry’ about the electrical safety of our neighbours boat, however, almost all Marina’s have RCD’s fitted and these do trip if there is a problem, which should protect your boat from excessive anodic action.
Our boat is getting on for 12 years of age and has probably spent most of it life bolted to mains shore power alongside (God knows what) in Marina’s. I specifically asked our surveyer if he could see any evidence of such corrosion and he showed me (particularly) along the waterline area, that there was absolutlely nothing visible.
Check out the MG-Duff website for full information on Anodic protection.
‘Don’t Panic’ CRB
Didn’t realise you were new to the forum – Welcome – Anodic corrosion is a very complex science and, as you so rightly say can be a huge problem in a marina, however my experience, over 25years of boating is that it not as big an issue as you may be led to believe.
With a GRP hull, you just need to ensure that internally the ‘bonding’ that is the cable from anodes to engine to skin fittings etc are really very ‘sound’ and making good contact with each other. There really is no common ground point, to tie them to, but the engine casing is as good as anything.
On a steel hull bonding is not an issue, provided the anodes are properly bolted to welded points on the hull and ‘visible’ to ‘dissimilar metals’ i.e. the prop and its shaft etc.
In a marina, we tend to ‘worry’ about the electrical safety of our neighbours boat, however, almost all Marina’s have RCD’s fitted and these do trip if there is a problem, which should protect your boat from excessive anodic action.
Our boat is getting on for 12 years of age and has probably spent most of it life bolted to mains shore power alongside (God knows what) in Marina’s. I specifically asked our surveyer if he could see any evidence of such corrosion and he showed me (particularly) along the waterline area, that there was absolutlely nothing visible.
Check out the MG-Duff website for full information on Anodic protection.
‘Don’t Panic’ CRB
EdWingfield
Well-Known Member
Without using a diver or a crane your option is to dry her out on the tide (often a free option) To do this you will need appropriate technique. Come back to this group if you need advice on that.
By the way, my own boat devours its anode every six months.
By the way, my own boat devours its anode every six months.
Haven't-a-Clue
Well-Known Member
I wouldn't mind some advice re drying out method as part of the o/b mount on my Merryfisher is constantly submerged and has an anode on it about the size of two polos' stuck together. I can't remember exactly where it is and I'm sure it needs changing now. Help! Ta everso.
Mudplugger
Well-Known Member
Can't help in regard to question...but if you are worried about marina berthing, have a look at the adverc site and comments about Galvanic isolators. ( by the way Welcome) HTH
Pete7
Well-Known Member
[ QUOTE ]
I wouldn't mind some advice re drying out method as part of the o/b mount on my Merryfisher is constantly submerged and has an anode on it about the size of two polos' stuck together.
[/ QUOTE ]
Given your location I would dry out of the public slip next to Moodys boat yard on the Hamble. Take a look at it during low water then beach it at half tide so you don't have to long to wait for the tide to lift her off again. Bottom will be course sand and gravel. Old tyre or fenders underneath the chines will help.
Pete
I wouldn't mind some advice re drying out method as part of the o/b mount on my Merryfisher is constantly submerged and has an anode on it about the size of two polos' stuck together.
[/ QUOTE ]
Given your location I would dry out of the public slip next to Moodys boat yard on the Hamble. Take a look at it during low water then beach it at half tide so you don't have to long to wait for the tide to lift her off again. Bottom will be course sand and gravel. Old tyre or fenders underneath the chines will help.
Pete
johnb2
Member
I'm sure you'll get lots of advice - here's my two penn'orth.
Drying out for a tide is a common and easy way to check underneath your boat. Many people do it regularly to scrub off their hulls.
You don't say where you are based but most harbours will have a scrubbing grid or a point on the harbour wall where you can dry.
Get local knowledge - it's worth a hundred messages like this. Your local harbour master or a local sailing club is the best source.
Done properly it is a pain free experience. You'll have time to nip up to the chandlers for a new one if you need it and you'll have time to get rid of the weeds as well.
Good luck!
JB /forums/images/graemlins/wink.gif
Drying out for a tide is a common and easy way to check underneath your boat. Many people do it regularly to scrub off their hulls.
You don't say where you are based but most harbours will have a scrubbing grid or a point on the harbour wall where you can dry.
Get local knowledge - it's worth a hundred messages like this. Your local harbour master or a local sailing club is the best source.
Done properly it is a pain free experience. You'll have time to nip up to the chandlers for a new one if you need it and you'll have time to get rid of the weeds as well.
Good luck!
JB /forums/images/graemlins/wink.gif
EdWingfield
Well-Known Member
Just to add to that already said.
Find a flattish bottom pref sand or shingle.
If you have a fin keel then you must prevent the boat from falling over outward from the wall. While still afloat move weight to the 'quay' side of the boat so that she now heels toward the wall. Then tie a rope from the mast to a strongpoint on the quay when she touches bottom.
Find a flattish bottom pref sand or shingle.
If you have a fin keel then you must prevent the boat from falling over outward from the wall. While still afloat move weight to the 'quay' side of the boat so that she now heels toward the wall. Then tie a rope from the mast to a strongpoint on the quay when she touches bottom.
MarkGrubb
Well-Known Member
...in the mean time, if you're worried that it may be wearing thin, then you can buy anodes that hang over the side. If you've got a GRP boat, then you probably just need to hang it at the back near your prop, to prevent interaction between the prop shaft and prop. Make sure you have it correctly connected up to the boats internal bonding system. Its my understanding that the bonding for sacraficial anode protection should be kept seperate from the electrical system.
When I brought my boat, it had one tear drop shaped anode amidships. The prop had some brittle spots which the surveyor commented had been caused by reduction of the zinc due to electrolysis. He thought the anode was to far from the prop to be of any benefit, so i put a collar type one on the prop shaft. It had erroded quite a lot after 4-months in the water, so I changed it in July. Boat is on a mooring bouy.
I imagine if you keep your boat in a marina then its more of a problems because there is so much more metal close by.
When I brought my boat, it had one tear drop shaped anode amidships. The prop had some brittle spots which the surveyor commented had been caused by reduction of the zinc due to electrolysis. He thought the anode was to far from the prop to be of any benefit, so i put a collar type one on the prop shaft. It had erroded quite a lot after 4-months in the water, so I changed it in July. Boat is on a mooring bouy.
I imagine if you keep your boat in a marina then its more of a problems because there is so much more metal close by.
Skylark
Well-Known Member
Why not contact your nearest British Sub Aqua Club branch and ask for some help? I'm sure that someone would be delighted to help. As both a diver and a sailor myself, I have no doubt that it could be turned into a interesting underwater recreational project, for neither hire nor reward. Of course, you could always learn to dive and then do your own mid season scrub, wire brush the prop and check the anodes!
actionoptics
Well-Known Member
If your boat has twin keels, take a trip to Benbridge and dry out on the sands. Turn left when you see the yacht club to port. If a fin keel, then quite a few places along the south coast have scrubbing places. You go along a wall at highish tide and rest on a flat , usually wooden sleeper, base as the tide goes down. There's one at Itchenor - see the harbour master first.
