130s-a split anode

[Ziffius]

Having had the engine serviced and gaitor replaced plus new anode I was a bit shocked to discover half way across the med that the anode had come off and been bitten by the prop.
To my eye it looks like the damage to the prop is all down to anode coming off, we didn't wrap anything round the prop to cause the anode to get pulled off. The company that fitted it deny any responsibility citing they follow volvo fitting specs so it must have been anode failure or external cause. Anyone else experience new anodes falling off their sail drive (split anode with a fixed 3 blade prop on 130S-A leg) to cap it all the rubber fairing was hanging off completely - I had  told the engineers they hadn't glued it properly!

[Symphony]

It will only come off if it is not attached properly. The screws need to be really tight. The way it is built it will not become detached even if it is well eroded. Similarly the fairing piece does not normally come off easily - but not a disaster if it does.

[Ripster]

Would think that is incorrect installation of the anode.  Perhaps not seated home properly when bolts tightened up or bolts not tightened at all.  I bet they didnt use any thread-lock either.  As has been said, these do not fall off if they are correctly installed.

[Odysseus]

I agree with the above its a fitting issue they probably did not use any loctite.

They fitted it their fault.
Odysseus

[Symphony]

Just to add a little more having looked at your photos. The anodes are attached with M6 setscrews that run into stainless steel inserts cast into the zinc. so even if the anode erodes completely the screws wold still be there through the mounting holes on the leg. The screws would seem to have come undone for the complete anode to fall off.

[Ziffius]

That was my thoughts exactly - poor workmanship. Unfortunately boat is in Sardinia and engineering company is in East Anglia so no hope of proving it to them. Biting the bullet and having prop repaired and new anode fitted in Sardinia - thinking about getting spare prop and cone nut and anode to carry just in case!!

[Symphony]

Sensible to have a spare anode. It can be changed underwater as the prop does not have to come off. You will need to be sitting down when you see the price of the spare cone nut and washer! If you are spending money on a new prop, consider a folding prop and keep your old fixed one plus the cone nut as a spare.

[Ziffius]

Well I had the diver replace repaired prop and a new anode in Cagliari while I was home working. Picked the boat up for the voyage to Corfu, my new base, and checked the anode/ prop was OK 1 day out. First chance to recheck was a week later and anode was gone and same type of damage to prop!!!!

I have a new prop, cone nut and anode with me that I brought from the UK but wishing I had got a folding one now. Going to haul the boat when I get to Gouvia to have the prop replaced and the rubber fairing re attached. If this third anode comes off I will scream!

[Ripster]

Well I had the diver replace repaired prop and a new anode in Cagliari while I was home working. Picked the boat up for the voyage to Corfu, my new base, and checked the anode/ prop was OK 1 day out. First chance to recheck was a week later and anode was gone and same type of damage to prop!!!!

I have a new prop, cone nut and anode with me that I brought from the UK but wishing I had got a folding one now. Going to haul the boat when I get to Gouvia to have the prop replaced and the rubber fairing re attached. If this third anode comes off I will scream!

So you had the anode and prop put on under water.  Well, I wonder how he did the anode bolts up?  They should be inserted and tightened on the anode, then given a gentle but firm clout simultaneously either side with a pair of hammers - not too hard or heavy, just to seat the two parts.  Then the bolts are re-tightened.  In addition, thread lock should be put on the bolt threads as they are screwed in to stop any vibration rattling them loose.  I bet your diver could not do this.

[Symphony]

That is not how the anodes are installed. They do not need banging together. Just tightening up with an Allen key. Can't understand why they are coming off as there is no load or movement on them.

[Ripster]

That is not how the anodes are installed. They do not need banging together. Just tightening up with an Allen key. Can't understand why they are coming off as there is no load or movement on them.

No not all anodes but clamp together ones need to pinch tightly to seat together properly and this way ensures that.  I do not mean whack them very hard, just some gentle clouts to seat them, then retighten. The bolts should then be thread locked. 

[Symphony]

Think you must be referring to shaft anodes which have a steel core and do need banging to get them to seat properly. Can't see it being necessary on a 130 split anode as once the zinc is tightened up on the mounting lugs it can't go any further, the heads of the bolts are in a recess and the nuts are captive.