Volvo Penta saildrive propeller advice

[haydude]

I have a Bavaria 42 Cruiser with D2-55 and 130S saildrive and fixed 3 blades 17x15 propeller.

The deep lead keel is absolutely fine, thank you for asking, not even an airline split on the hull joint (with a Dufour and iron keel I used to get a few millimiters on the aft).

I am replacing this propeller with a Volvo Penta folding. Why Volvo? Because it is the only folding prop I can afford right now, competitors are too expensive.

Since I stressed that I loved the performance of the fixed prop under motoring the yard recommended an 18x15 3 blades size to compensate for reduced blade surface (aspect ratio?).

I read in this forum that some owner complain about excessive anode wastage on these VP props.

Please could you advise around the sizing criteria and anode issues? Are the latter generalizable or rather exceptions? What is your experience if you own VP folding prop?

 

[Tranona]

not sure about the need to go up an inch in diameter - would look for some independent support for that. On my Bavaria my folding (2 blade) is the same diameter and pitch as the fixed one and performance is virually identical.

You are right to be concerned about rapid anode wastage, although I hear it is better now than when they first introduced folding props. I have a Flexofold, which is very good, but a little more expensive than the Volvo and it does not have (and I hope not need) an anode although i think their 3 blade one does. Anode wastage varies enormously from boat to boat and location to location. If you main leg anode lasts well that might indicate that the prop one will. If you connect to shorepower a galvanic isolator is a must.

 

[haydude]

If you connect to shorepower a galvanic isolator is a must.

Thank you Tranona. Is a galvanic isolator necessary even if I do not have any wiring at all going to either keel, engine and most obviously saildrive? Practically I have no 12V negative going anywhere but the batteries. Also the Mains earth is connected only to the shore power earth and nowhere else.

 

[Blue5]

We have a VP sail drive and folding prop and yes the wastage on the prop is significant, the leg anode lasts a couple of years but the prop anodes about 6 months.

At present we are testing a hanging anode as suggested by MG Duff and we are only using shore power when absolutely necessary, be interesting to see if these actions produce any better results.

 

[scottie]

Have you considered the kiwi prop ?

 

[Tranona]

Thank you Tranona. Is a galvanic isolator necessary even if I do not have any wiring at all going to either keel, engine and most obviously saildrive? Practically I have no 12V negative going anywhere but the batteries. Also the Mains earth is connected only to the shore power earth and nowhere else.

Galvanic isolator needed even if you do not switch shorepower on. Just being plugged in leads to the possibility of stray currents - nothing to do with corrosion between dissimilar metals. Google for further information - and saves me trying to (probably badly!) explain it.

 

[Tranona]

We have a VP sail drive and folding prop and yes the wastage on the prop is significant, the leg anode lasts a couple of years but the prop anodes about 6 months.

At present we are testing a hanging anode as suggested by MG Duff and we are only using shore power when absolutely necessary, be interesting to see if these actions produce any better results.

Will be interested to hear if you have any luck with the hanging anode. Difficult to see how it can do anything for the prop anodes as it is not possible to connect it directly to the prop, which is isolated electrically from the leg. The wastage of the prop anode is solely related to the metals in the prop.

 

[haydude]

Have you considered the kiwi prop ?

Yes and I decided against because it is a feathering prop. One of the reasons I want a folding prop is that my area is pestered with irresponsibly marked fishing gear and a folding prop would reduce the chances of entanglement, whilst a feathering would actually increase them.

 

[Blue5]

Will be interested to hear if you have any luck with the hanging anode. Difficult to see how it can do anything for the prop anodes as it is not possible to connect it directly to the prop, which is isolated electrically from the leg. The wastage of the prop anode is solely related to the metals in the prop.

Agreed, I am sort of sceptical knowing the prop is isolated but I am giving it a go, will post the results in about six months time.

 

[Tranona]

Yes and I decided against because it is a feathering prop. One of the reasons I want a folding prop is that my area is pestered with irresponsibly marked fishing gear and a folding prop would reduce the chances of entanglement, whilst a feathering would actually increase them.

If that is a concern then fit a rope cutter. Think it is a bit of a fallacy that you won't catch ropes etc with a folding prop. The danger is when you are motoring if you are worried about getting things round the prop. Not suggesting a folding prop does not have advantages over a feathering prop, but doubt it makes any difference to getting entanglements.

 

[VicS]

Thank you Tranona. Is a galvanic isolator necessary even if I do not have any wiring at all going to either keel, engine and most obviously saildrive? Practically I have no 12V negative going anywhere but the batteries. Also the Mains earth is connected only to the shore power earth and nowhere else.

If your shorepower earth is definitely not connected to the 12volt negative or the anode system or any other part of the boat apart from the mains power sockets you do not need a galvanic isolator.

BUT the current best advice on shower power systems is that the shorepower earth should be bonded to the DC negative .. then of course you do need a galvanic isolator unless the shorepower connection is seldom plugged in.

 

[Sans Bateau]

Before we fitted a galvanic isolator, the leg anode barely lasted a season, now with one we could just get 2 years at a push.

The Flexofold that Tranona mentions is our choice too. If you didnt know it came out very well in the Yachting monthly prop test. Have you tried 'doing a deal' with them?

 

[Quandary]

I have had a VP 3 blade folder on a 130s leg for four years now. We rarely use shorepower and the boat is in fresh water more than half the summer. The fitted Navix shorepower set up is claimed to include galvanic isolation but with no power on our berth and the majority of places we visit it does not really matter too much, the shorepower is mainly to see the batteries through the winter when ashore. I have been using a hanging anode connected to the top of the leg for all that time and it is hung as close to the prop as I can get. The leg has never been antifouled but is coated with Propshield lanolin wax every couple of years, I do not waste time putting it on the prop any more but it gets polished well.The hanging anode protects the leg anodes which is good, for with a rope cutter they are twice the normal price and half the weight, it also allows me to remove fresh water passivation if I am not in salt water for a couple of weeks.
The prop anodes are just about there after 6-7 months and would not last 10. At first I was concerned that the hanging anode may have been speeding their demise but it seems to be the normal lifespan as far as I can determine. The rope cutter has not visibly affected anode life. I am comforted that the anodes are effective as with all the other metals in the leg and prop. it could be very expensive if they did not.
Its a great prop though driving well ahead and astern with not too much walk and no clunking when changing gear, I would use one again even if it does mean drying out every autumn and spring.

 

[youen]

propshield

I have had a VP 3 blade folder on a 130s leg for four years now. We rarely use shorepower and the boat is in fresh water more than half the summer. The fitted Navix shorepower set up is claimed to include galvanic isolation but with no power on our berth and the majority of places we visit it does not really matter too much, the shorepower is mainly to see the batteries through the winter when ashore. I have been using a hanging anode connected to the top of the leg for all that time and it is hung as close to the prop as I can get. The leg has never been antifouled but is coated with Propshield lanolin wax every couple of years, I do not waste time putting it on the prop any more but it gets polished well.The hanging anode protects the leg anodes which is good, for with a rope cutter they are twice the normal price and half the weight, it also allows me to remove fresh water passivation if I am not in salt water for a couple of weeks.
The prop anodes are just about there after 6-7 months and would not last 10. At first I was concerned that the hanging anode may have been speeding their demise but it seems to be the normal lifespan as far as I can determine. The rope cutter has not visibly affected anode life. I am comforted that the anodes are effective as with all the other metals in the leg and prop. it could be very expensive if they did not.
Its a great prop though driving well ahead and astern with not too much walk and no clunking when changing gear, I would use one again even if it does mean drying out every autumn and spring.

Are you happy with Propshield why dont you apply it to the propeller.Yesterday I tried to put some on my propeller with a brush after having warmed the Propshied I was not happy with the result which was not very smooth

 

[Quandary]

Are you happy with Propshield why dont you apply it to the propeller.Yesterday I tried to put some on my propeller with a brush after having warmed the Propshied I was not happy with the result which was not very smooth

Because the rotation wears it off in no time, the exposed parts of the prop are bronze and do not need protection as much as the teeth which you can not really coat anyway. I polish it and it stays clean, perhaps we motor too often?
Having tried to extend the life of bronze two blade folders in the distant past by epoxy painting, I soon realized that the important bits that wear are the bits you can not coat. A folder depleted until it was pink after losing a shaft anode years ago persuaded me that the anode was the vital part of protection.
I use a gas blowlamp with a soft flame to smooth the finish on my propshield but you do need to be careful and keep it moving. It is easiest to apply if really well warmed but put on a cold surface on a freezing day, easier for me than you perhaps?

 

[aluijten]

I have experience with volvo and non volvo folders and to me it is clear that the three bladers from volvo have excellent performance but the alloy they are made from leaves something to be desired. It really eats through anodes (only the ones actually on the propeller) and wears out faster then others (play on the hinges). I'm pretty sure the bronze they've used is of lesser quality then for example Gori.
Because of the wear it becomes noisy at idle speeds and switching gears. Nothing really problematic though.
All in all I think it's an okay propeller but not the best. I do like the simplicity of the whole mechanism and locking of the blade pins. There is little that can go wrong there.

 

[billmacfarlane]

Volvo replaced my folding prop after 1 season of use when the boat was new as the anode deterioration was that bad. I switched to a Kiwi which I've had for 5 years. I'm getting rid of it and buying a Flexifold 3 bladed folder as the performance of the Kiwi isn't all that great. You might be interested to know that Darglow are offering 20% discount at the moment. I've just ordered mine.

 

[PeterR]

We have a VP sail drive and folding prop and yes the wastage on the prop is significant, the leg anode lasts a couple of years but the prop anodes about 6 months.

At present we are testing a hanging anode as suggested by MG Duff and we are only using shore power when absolutely necessary, be interesting to see if these actions produce any better results.

This is typical for Volvo saildrives. A hanging anode (attached to the pushpit) was completely ineffective for me. A galvanic isolator helped. A lot of people say they lose there prop anodes after a few months. That is because the thinnest part of the anode is where the bolt passes through it, as the anode weakens centrifugal forces shed the rest of the still viable anode. You can improve matters by antifouling a thin stip of the anode around the bolt. This preserves the middle of the anode and the rest will then continue to function for about a year.

 

[Neil_Y]

On my Bav 40' (390) the twin bladed volvo folder was almost as good as the two bladed fixed, only difference was the slight delay and and grunt going quickly astern. The folder felt like it was slipping.

Never an issue with the anodes, only problem was one blade fell off the folder so went back to the fixed.

 

[Quandary]

Volvo claim that the design of the leg/ prop combo is such that the prop is electrically isolated from the leg, unlike shaft drive where there is contact. This is necessary because of the mix of alloys that make up the components but it means that the prop is entirely dependent on the small anodes screwed to it. My hanging anode is easily wired back to the leg to give it extra protection but you can not do anything similar with the prop. I do not understand the post about hanging an anode from the pushpit, how does that work?
I do not accept the 'inferior bronze' notion or that undue wear occurs in the moving parts. While I have only had 2 blade folders of different makes before this one, I recall wear between the ss pins and the bronze blades as being more rapid than on the three blade which so far feels exactly as it did when new. No waggle at all.
A solution might be to turn a wider slot in the boss if it were possible to source or cast heavier anodes but unfortunately I suspect there are not enough of these props around to encourage anyone to offer a modification. However I like my prop, it is well engineered and an elegant piece of design so I will just happily continue to renew the anodes, at worst it means lying against the pier wall on a spring tide for a few hours once a year.