Author Topic: Folding Prop  (Read 6656 times)

tckearney

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Folding Prop
« on: June 10 2016, 22:04 »
Hi I have a 2000 B42 with the Volvo MD22 37KW engine.  I am considering fitting a folding prop but funds are tight.  I do a fare bit of motor sailing if on long passages.  Could anybody advise the best value for money.  I do not race or intend to, but would like less drag when sailing.   Has there ever been a YM article about these with a YM best value recommendation.  I also go astern into most moorings. 

Craig

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Re: Folding Prop
« Reply #1 on: June 10 2016, 23:21 »
Having sailed a Bavaria 38 ( 2009) with a 3 blade folding prop and also one with a fixed, 3 blade prop the only difference I noticed was when going astern.

The folding prop does not "Grip" in reverse and I estimate you need around 50% more revs in reverse for the same result. I would not worry about this unless you need to tie-up against a strong current.

It is hard to estimate but I can't see any difference in forward gear and appear to get similar fuel consumption to most other boats.

My folding prop was purchased with the boat and, I'm sorry, I don't know the model. It may be a Volvo prop.

Craig
"Shirley Valentine"
Gold Coast
Australia

njsail

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Re: Folding Prop
« Reply #2 on: June 11 2016, 12:48 »
regarding props im sure you will see everyone has their favorite.  Look at past folding prop threads as well.   Many years ago we put a kiwi feathering prop on our bavaria 40 ocean.  It wasnt as expensive as some of the bronze folders as this would feather and has composite blades.  Simple design and worked great.  Really rough estimate is we gained between .5 and 1kt depending on conditiion. i could really feel yhe differemce withlit the prop drag and on the bav 40 ocean the prop is directly under the podium.   Easy to maintain and you use regular bottom paint on the blades.  i had the opposite experience from craig where the prop in reverse flips around and gives an even bigger bite/more grip to stop quicker.   I have aeveral friends with the kiwi prop and they all say the same thing...reverse stops quicker than a fized blade because the way the prop changes blade angle in reverse.  Just my 2 cents.  There are plenty of good folders/fearhering props out there.   Good luck in your quest.  I dont miss the tail cone asse.bly on the fixed aluminum prop the boat came with.   Ive heard more stories of thw cone spinning off.   Loc tight can be your friend.

Symphony

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Re: Folding Prop
« Reply #3 on: June 11 2016, 15:32 »
You may find you are better off with a feathering rather than a folding propeller. You need a 3 blade and a folder is similar price to a feathering prop. Suggest you look at the Flexofold and the Featherstream, both available from Darglow in the UK. You will get good advice from them on the pros and cons.

geoff

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Re: Folding Prop
« Reply #4 on: June 11 2016, 17:58 »
My vote goes to the Kiwi, better speed in forward and terrific in reverse. Its like hitting a wall!! Geoff

Aquila

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Re: Folding Prop
« Reply #5 on: June 12 2016, 09:38 »
I know you have a budget but I fitted a Darglow feathering prop this year and it's amazing.  I was out last weekend and she went so well and much faster.  I went for the feathering after much research because I didn't want a delay in reverse gear and also i didn't want the folding prop fouling should you ever pick up a rope.  This happened to me once when my mate picked up an illegal pot which sliced through with rope cutter but then weight of rope held folding prop shut!  Feathering prop workings are all enclosed and geared to actions in drive is immediate.  I am amazed difference compared to my old two bladed fixed Volvo prop.  They are a lot of money but I think it's worth it.

Skipperwales

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Re: Folding Prop
« Reply #6 on: June 12 2016, 18:51 »
I fitted a flexofold to my 39 and gained about half a knot when sailing. Speed under power is unchanged and the she stops just as quickly. What did change was that there was much less prop wash, especially in astern and that made turning her in marinas much more troublesome so I ended up fitting a bow thruster, so the costs just multiplied. Bill.

Craig

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Re: Folding Prop
« Reply #7 on: June 13 2016, 00:13 »
I agree with most of the above comments. If I had a fixed prop today, I would change to the Kiwi Feathering prop, no worries.

Reverse Thrust is a feathering props main advantage.

The last time I checked, the price of the Kiwi Props were about 1/2 the price of other folding or feathering props and very easy to fit.

I am a bit confused about the comments that a feathering prop is better than a folding prop in regard to snagging crab-pots.  I would have thought that a feathering prop is more likely to snag as the blades stick out much further and the folding prop is more streamlined when folded. 

I've run over numerous lines over the last 6 years and around 15000nm in the Med and Australia and never had a line foul the prop. I've had rubbish foul the keel and rudder. I don't have a rope cutter installed and never felt I needed it with a folding prop.

Craig
"Shirley Valentine"
Gold Coast
Australia

Salty

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Re: Folding Prop
« Reply #8 on: June 13 2016, 07:36 »
................so the costs just multiplied. Bill.

Just an aside Bill, but owning a boat must be almost as effective at separating a man from his money as getting divorced !!

Jackho

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Re: Folding Prop
« Reply #9 on: July 12 2016, 21:27 »
I would simply purchase the Volvo folding prop, as sized and recommended  by Bavaria. It is also the cheapest and apparently made by I think flexifold .   I followed this advise and it simply transformed my sailing / motor sailing performance and astern handling greatly improved.
Bavaria publish a prop. sizing data sheet for their range of boat and engine combinations.  I have one on the boat if you can't source.  Hope this helps .

Salty

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Re: Folding Prop
« Reply #10 on: July 12 2016, 23:34 »
Hi ................. I am considering fitting a folding prop but funds are tight............. Could anybody advise the best value for money.................I also go astern into most moorings.

I fitted a folding prop at the beginning of this season, and now that it's been on and in use for a while enough for me to get a feel for it, herewith my comments.
It was purchased second hand through eBay, and is an early Volvo bronze folder that had seen some use where a little corrosion was evident on the ends of central part where it fits to the saildrive shaft. That aside the rest of the prop was in excellent condition and was exactly the same diameter and pitch as the old fixed aluminium prop that it replaced. It gives good bite both ahead and astern, and the only difference in use has been a more conscious allowance of a moment or two between going from ahead to astern or vice versa.
Regarding funds being tight and best value for money, the seller on eBay had advertised the prop under the wrong heading such that mine was the only bid, and he had started the bidding low such that I got it for £100, and I thought that was really good value. Does it work £100 better than the aluminium prop it replaced, - yes I think so where as much as anything there is less drag with the prop folded, but I don't have any definitive data to be able to say it does this or that by this amount better than the prop it replaced. As for going astern, it really does seem to bite well such that overall I'm pleased with the result of the change and particularly that I didn't have to shell out loads of money for it. I don't know why the previous owner of the prop chose to sell it, but so far there have been no regrets, only a little concern that I didn't use any locktite on the threads of the grub screws that secure parts of it in place. So the best value for money in my opinion was a pot luck bid on eBay.