anode replacement ?

[paulburton44]

My boat has an anode about 10 inches long, bolted through the grp hull.
The anode is a far bit corroded ?
Should i just clean it up with a wire brush (still plenty there)
or
Replace.?
I do have a replacement but i am unsure about removing the existing one and getting a good seal on the new ones bolts ?
Would i seal it with epoxy or a flexable sealer like sikaflex ?

<hr width=100% size=1>www.withamsailingclub.co.uk

 

[Sea Devil]

You need to replace it - normally annually or when they become 25- 30% ish used - Just undo the the two bolts - one at each end on the outside of the hull - the anode and plate will drop off - you might need to wire brush the thread on the bolt.

Just check the bolt on the inside is not turning or too rusted. If it is loose or heavily rusted just replace it with similar and sicaflex it in with underwater sicaflex but this in not useually required.

<hr width=100% size=1>If you have time please visit my web site -
<A target="_blank" HREF=http://www.michaelbriant.com/sailing>http://www.michaelbriant.com/sailing</A>

 

[branko]

You can isolate anode with paint or seal but be shure that have connection with metal part (which is protected) thrue anode screw.


<hr width=100% size=1>skipp

 

[Piers]

The norm is to replace it when it's half gone. When replacing, make sure the bolts are clean and make good contat with the anode. In other words, don't use anything that could insulate the bolts from the anode.

As a last check, check the wire connections on the bolts on the inside of the boat are in good condition, and not themselves coroded and about to come loose.

<hr width=100% size=1>Piers du Pré
http://www.dupre.co.uk

 

[tcm]

It's said that a good guide is that if over 50% is still remaining, leave it on. Compare with the replacement new one to see how it's doing.

Sikfles is often used on/around the nuts to holdem, epoxy mite make it a bit tough to get off when corroded. Note that the holes/studs should make a metal-metal contact with the anode when you do replace, praps sikflex on the final nut to ensure it doesn't unscrew. Of course, the surface of the anode must remain raw unpainted.

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[Kurrawong_Kid]

A surveyor warned me not to wire brush them. Said to clean the anode off with a cold chisle. Something to do with leaving small particles which then accelerate the wasting away. Can't remember the exact reason but it sounded plausible at the time

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[mdrifter]

You shouldn't have to remove bolts provided they've been installed correctly and are not wasted...The flat plate should be on the outside of the hull and not inside - just have a look around any hard to see many incorrectly installed. Don't forget the serated washers.

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[paulburton44]

Well been on the boat this morning.

removed the anode and bolts.

They were bolted from the outside, with 2 nuts on the inside. There were 2 wooden spacers between the hull and nuts on the inside.
Looks like they were sealed with sealant.
Now left with 2 holes in the bottom of the boat ?

<hr width=100% size=1>www.withamsailingclub.co.uk

 

[Sea Devil]

Really you should not have removed the bolts! Not necessasary unless wasted or very tired...

Either use the bolts again with the washers that were on them and perhaps some underwater sicaflex or get some new ones of the same dimensions and sicaflex them in - There are normally washers on the outside between the anode and the hull...

The hole is normally tight so you have to screw the bolt in and frequently there is a washer on the head of the bolt on the inside.

I have sometimes changed anodes with the boat in the water - by swimming underneath - diving - but not in UK waters

<hr width=100% size=1>If you have time please visit my web site -
<A target="_blank" HREF=http://www.michaelbriant.com/sailing>http://www.michaelbriant.com/sailing</A>

 

[Sailor_pup]

I know what an anode is but what purpose does it serve on a boat?

Where is it placed on the boat?

<hr width=100% size=1>My brain is a sponge, your advise is the water.

 

[BrendanS]

The anodes on boats are 'sacrificial'

The idea is that they erode rather than any expensive metal bits that are in the water like shaft, props or outdrives when exposed to electric currents in the water which can be caused by the different metals in the water and attached to the hull, or due to stray currents in the water frequent in marinas etc

Depends on the boat and it's propulsion gear, but anodes are usually on the shaft assembly, saildrive, or outdrive and sometimes on the hull etc

<hr width=100% size=1>Me transmitte sursum, caledoni

 

[towzer240]

you could try looking at the duff web site.
www.mgduff.co.uk.
sorry can not do a link

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