New prop advice

I've only ever had a Brunton (feathering) autoprop and a heavy long-keeled boat. I don't know how much is down to the prop and how much is down to the boat in general, but she is a pig to manouevre, but I always manage somehow. However, she is a *sailing* boat and when I lock the prop and the blades feather, I get another half a knot of speed, which is worth a lot to me and the family over multi-day passages. I used to get very nervous about manoevering in harbours, but really, it just takes some practice. If your boat won't reverse into your marina berth, go in forwards instead! If she won't stop promptly enough, when you hit reverse, engage reverse earlier!
 
roaringgirl said:
I've only ever had a Brunton (feathering) autoprop and a heavy long-keeled boat. I don't know how much is down to the prop and how much is down to the boat in general, but she is a pig to manouevre, but I always manage somehow. However, she is a *sailing* boat and when I lock the prop and the blades feather, I get another half a knot of speed, which is worth a lot to me and the family over multi-day passages. I used to get very nervous about manoevering in harbours, but really, it just takes some practice. If your boat won't reverse into your marina berth, go in forwards instead! If she won't stop promptly enough, when you hit reverse, engage reverse earlier!
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I dont think practice is the answer, I would rather address the problem
 
mrangry said:
I dont think practice is the answer, I would rather address the problem
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I say this with the greatest of respect, So please do not take offence. But the problem could be the bloke on the helm. Boats do not park themselves, or for that matter sail themselves. I am sure that you understand that. Many problems can be resolved with a bit of perseverance
Of course if you have tried- & failed- then other options have to be sought. But I tend to give it a good try first & think laterally for a while. .
Some boats are pigs to park, but their owners work out how to manage it & get on quite well in the end. It is just a case of knowing how. That takes practice.
For me boat handling in a marina is something of pride. To others it is just a means to an end- To each his own
 
Daydream believer said:
I say this with the greatest of respect, So please do not take offence. But the problem could be the bloke on the helm. Boats do not park themselves, or for that matter sail themselves. I am sure that you understand that. Many problems can be resolved with a bit of perseverance
Of course if you have tried- & failed- then other options have to be sought. But I tend to give it a good try first & think laterally for a while. .
Some boats are pigs to park, but their owners work out how to manage it & get on quite well in the end. It is just a case of knowing how. That takes practice.
For me boat handling in a marina is something of pride. To others it is just a means to an end- To each his own
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No offence at all. I have sailed in many boats owned both by myself and others and this is definitely not a case of poor judgement or helming. The boat simply has no power astern, taking forever to stop no matter what engine revs are applied. If it wasn't for the fact that i go astern when leaving the berth, albeit very slowly at high revs, I would say the prop is not engaging when going astern. But it does move albeit very slowly.

Once lifted out next week I will be able to identify the prop size and pitch and also whether it is fully engaging and take it from there.
 
The boat is now out on the hard and a cursory examination revealed no obvious issues with the folding prop. Before I decide on whether to buy a feathering prop I thought I would price a fixed three blade unit. The problem is, I cannot find out what the original prop diameter and pitch was. Any tips on where to look as my email to Beneteau has had no response?
 
Enter your boat data here

vicprop.com/displacement_size_new.php/?m=1

and that will give you a pretty good guide. If you are buying a prop then for a foxed prop go to a specialist such as T Norris or Lake Engineering, give them the data and they will calculate and supply an appropriate propeller. Equally if you want to invest in a feathering or folding propeller then go to one of the experts such as Darglow Engineering who will also supply you with the correct prop. There is virtually no risk involved in either approach. These people have decades of experience and have supplied props for thousands of boats so you can be confident you will get what you need.

As you have probably gathered a 3 blade folder or feathering prop will do what you want. There are pros and cons of each type which Darglow in particular will explain (they make or sell both types) but in reality either type will perform well. There is nothing out of the way about either your boat or your engine that would suggest you need anything out of the ordinary.
 
These nasty duck billed 2 blade folders are always totally pants in reverse. Frankly they are pretty rubbish in forward too! My advice would be a 3 blade Brunton. They are expensive but absolutely wonderful bits of kit. The blades are "self pitching" which means they adopt the best possible pitch to transmit the power available related to sea state, wind, tide etc and you will DEFINITELY gat better speed under any conditions than that nasty 2 blade thing. They do exactly the same in reverse although you need to give the throttle a quick burst astern to reset the blades so there is a delay of several seconds when you "put the brakes on" but once you get used to this they are very efficient in astern too. Couple this with the fact that they "feather" when sailing giving almost no resistance and its win /win/win . I don't know anyone who has fitted one that has not been delighted with it. The only downside is that every year it is wise to inspect and clean the bearings to maintain optimum performance but if you haul out every winter that's not a problem.
 
The original prop size would be nice to have but is not essential any reasonable supplier or calculator will manage without it but aperture will be required
the comment about the inefficiency of clam type 2B folders is little bit unkind but the do probably get near to that state eventually
 
scottie said:
The original prop size would be nice to have but is not essential any reasonable supplier or calculator will manage without it but aperture will be required
the comment about the inefficiency of clam type 2B folders is little bit unkind but the do probably get near to that state eventually
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This is a bit of an old wives tail now. Certainly some of the early simple 2 blade folders aimed at the racing market were pretty lousy for propulsion, not helped by some being fitted to engines of marginal power. However as the YM review showed, that is clearly not the case with more recent properly designed folders which are at least equal to fixed equivalents or sometimes better.

One of the problems with these props is that there is a large choice and they are expensive so difficult to decide if you don't have experience of them. The Bruntons ffor example which has been suggested has particular characteristics which make it attractive for particular types of boats and modes of usage. it is popular on larger boats that spend a lot of time motorsailing, for example in the Med where its ability to increase the pitch and run at lower revs for a given boat speed is valuable. However, some people find its low speed characteristics with delays and hunting for the right pitch a bit difficult to live with.

Undoubtedly the most popular choices are either the mechanical feathering type such as a Maxprop or a Featherstream or good folders like FlexoFold or Volvo (although the latter has an appetite for anodes!).
 
I wouldn’t hesitate to recommend a darglow feather stream for cruising.

its my go to for fitting on pretty much everything. Well engineered and well priced.

that said I have a old twoblade folding gori on my boat. Can’t seen any need to change it works perfectly adequately abs in fact the boats probably a little overpowered in fact!
 
mrangry said:
The boat is now out on the hard and a cursory examination revealed no obvious issues with the folding prop. Before I decide on whether to buy a feathering prop I thought I would price a fixed three blade unit. The problem is, I cannot find out what the original prop diameter and pitch was. Any tips on where to look as my email to Beneteau has had no response?
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I might be mistaken but if you keep your boat at Clyde Marina why not have a word with the guys there? They are Beneteau agents and I'm sure would be able to get the info for you.
 
I have decided to purchase a featherstream prop from Darglow, however upon trying to remove the old folder the hub is stuck on the shaft. Trying to locate a puller locally has met with a dull thud. I dont suppose anyone localish to Paisley or Ardrossan has a puller I can borrow?
 
mrangry said:
I have decided to purchase a featherstream prop from Darglow, however upon trying to remove the old folder the hub is stuck on the shaft. Trying to locate a puller locally has met with a dull thud. I dont suppose anyone localish to Paisley or Ardrossan has a puller I can borrow?
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Quite easy to make a propeller puller

puller_3.jpeg
 
The Clarke hydralic pullers quite good for the money if your treating yourself.

But as indicated in post 57 you can make your own pretty easy.

You can also drill and tap the boss of the prop in three places then one flat plate with matching holes is all you need. It’s how we deal with 5 blade props I drill and tap those from new.
 
If you want better prop response and better power/grip astern, then 3-balde Featherstream every time.

I changed out my 3-blade fixed prop for one and the difference was incredible.
 
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