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Hi to one and all from Island Girl
Just returned from a long cruise to the Baltic and back so if anyone wants any info please contact us.
Serious question re folding proppellors of any sort ,can anyone comment on the performance gains that can be realised.?
Island Girl is a 2000 37 with a Volvo 2030 with a standard fixed 2 bladed Volvo prop .
Points will be awarded!
Sue and Graham
Island Girl back in DoverHi Graham
I would be interested in hearing about your Baltic adventures as I’m sure would others. How about an article in the Magazine?
Regarding folding props, I have a 3 blade folding Volvo prop (replacing the original 3 blade fixed), coupled to a Volvo MD22 (50HP) on Playtime. One reason for fitting the folder was to stop the feathering prop rotating when sailing. It used to be quite noisy and it must slowly wear the gearbox bearings etc. Volvo recommend you don’t put the gearbox in reverse with the fixed prop as it jams and you have to start the engine to unjam it. There is no such problem with the folder; I sail with it in reverse and it slips back into neutral before engine restart without problem.
Regarding gains in sailing performance, I can’t quantify it but it is definitely a bit quicker. There is also no problem at all with reverse – it bites immediately and will do crash stops when berthing etc. if required.
If you do a lot of longer distance sailing I would recommend a folder. The Volvo one is good (but not cheap) but there will probably be others along shortly to recommend Brunton or Kiwi or, or . . . You pays your money and takes your choice!
Good luck
Roger
Hi Graham,
I have a volvo 2 bladed folding prop on my Bav 36 with a 2030D engine.
Sailing performance is greatly improved, in flat water I reckon it can put half a knot on boat speed.
The volvo 2 blader is probably one of the cheapest folding props on the market and is great when sailing however the bite when going astern is not particularly good so crash stops normally end up with a crash if you’re not careful.
Once going astern though it is fine and crash stops from going astern are as good as you can get.
It’s also very simple mechanically and all parts can be replaced individually if they break.
One other down side on the 2 blader is that the prop anode comes in 3 segments and can chorode very quickly. I can just last a full season between lift outs but some other owners have reported only going 4 to 6 months before having to replace the anode. I believe the 3 blader has a full single piece anode and is more durable.
Regards
RickRick has just reminded me about the anode problem. Unfortunately, the 3 blader has the same 3 small anodes as the 2 blader and they do corrode quickly.
One tip is to put a line of paint around the screw holes as they corrode around the screw heads first (best electrical contact, I guess) and then the rest of the anode just flies off.
With the paint trick they will just last 12 months.
The saildrive has a large circular anode inboard of the prop boss on the shaft but this lasts for 3 or 4 years.
I thought the Volvo prop was expensive but maybe I’ve lost touch. I fitted mine 7 or 8 years ago.
Roger
Roger
The 2 bladed prop is cheap compared to the 3 bladed. From recollection 4 years ago the 2 blader was a tad over £450 and the 3 blader was nearly £800 at the time.
I went for the 2 blader because the extra performance under power of the 3 didn’t justify the additional money on a sailing yacht.
And I forgot to mention also about the paint trick. That is something I have always done on the prop anode.
RegardsThanks for the tip about painting the screw holes, I’ve just purchased a Volvo two blade folding prop through ebay for a modest £95. With the boat just back into the water, it will have to wait until next dry-dock before fitting.
I have just fitted a Flexofold 2 blade to a 2030 in a 2001 B37. I carried out comparative tests for speed, stopping distance and bollard pull before and after and overall performance is virtually identical with the standard fixed 2 blade except it only reaches 3300 rather than 3600 – but the speed throughout the range is the same. There is a slight delay in reverse unless you give it a bit of revs to open the blades and there is a little bit of chatter at low revs if the blades are not fully open. Not able to comment on the sailing performance yet as only fitted on Thursday! The reason for choosing this particular prop is that it seems to be better made than the Volvo and does not need anodes.
I have just fitted a feathering Kiwiprop to my 2006 B33 and first indications are really good. The blades are composite, so anode corrosion is expected to be low. Performance astern is startling and something to get used to when manoeuvring in small spaces. I think I’m getting at least half a knot, possibly up to one knot extra ahead on engine and definite improvement under sail which has yet to be assessed but they do say one knot can be expected. Bit of noise when accelerating under engine which may be cavitation at the blade tips. When I’ve been out for longer, I’ll post again.
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