I am looking to replace my 2 blade fixed prop with something different.
A 40ft 8 tonne boat with a 40hp Volvo penta and 130s sail drive.
I am thinking 3 blade folding or feathering.
Would be interested to hear peoples opinions and any good or bad experiences.
Cheers riffraff
Hi RiffRaff-Our last yacht had a 120s sail drive with a two blade folding prop fitted. The situation was we used to cruise @ 5.5-5.8 knots under motor but it had little bite when going astern. Big problem negotiating the mooring or when docking somewhere.
We retrofitted with a three bade Volvo folding prop and as promised, it did have the same thrust going astern as it did going forward.
Cruise speed was also up from the previous to around 6.2-6.5 knots.
The additional drag for us was hard to notice and I figured maybe 0.2 of a knot penalty there, at worst.
Certainly did not cost us racing around the 'cans'.
Our yacht was only 4.8 tonne displacement and it will be interesting to see what else may be out there that really works.
All the best on this Australia Day!-CR.
I replaced my 3 bladed fixed prop with a varifold 2 blade folding prop, There is very little difference in forward although it struggles a little more into a headwind. Reverse is fine.
The difference in light air sailing is massive. Its well worth doing.
Probably not quite as flash as the gori 3 blade but at $1500 much better fir the budget.
I've got a Seahawk self-feathering propellor on my boat. Goes well in both forward and reverse and prop walk never seems an issue (but that could have more to do with hull shape). You can adjust the pitch separately for forward and reverse and when not in use the blades feather flat (once the engine is off, move gear shift from Neutral to reverse and back to neutral).
I've stripped it right down and rebuilt (nothing wrong but just checking it's internals) it but it helps if you put a few centre pop marks in first so you know which bit goes where, when reassembling. It can be greased while in the water and also the blade pitch can be adjusted easily when in the water. Just need an alien key and ring spanner. (Also helps if you can hold your breath)
As far as recommending it, well I've had a good run out of it but since I've never had any other type of prop on my boat, I can't say if it's better than something else. But being able to change the pitch is a real bonus.
www.seahawk.com.au/
I have a Seahawk feathering prop also, and although I haven't spent a great deal of time onboard yet, I was amazed how positive the feedback was to the helm when I first took the yacht for a spin using the motor - forwards or reverse.
Yacht weighs 14t with 65hp motor.
After reading the manual, the options for adjusting pitch (if you know what you are doing or course) are a real bonus.
Best of all - Aussie made and invented!
I fitted a 3 blade volvo folding prop soon after installing a new D1-30 and S130SD previously I had a fixed 3 blade aluminum i think the new one works just as well and has heaps of thrust in reverse. So i would tend to say a lot will depend on your docking abilities. There is a hub for a Volvo sail drive on gumtree at the moment you would only need to buy the correct blades to suit then.
I replaced my 3 blade fixed aluminium prop on my Volvo 120SD with a Flexofold folding prop about 5 years ago. Under power there's little difference in performance from the fixed prop. I reverse into my berth without any problems, I just have to give it a few more revs to get the prop to bite, then back off.
Under sail there was a significant improvement in boat speed. The folding prop was the best money I've spent on the boat as it gives you improved performance on every point of sail without any additional effort.
Well talk about bring on another thousand.
I dropped the oil in the sail drive today and there was signs of water contamination.
I removed the bottom gear to replace the seals and noticed a couple of wear rings where the seals sit.
$900 for a new shaft and a couple more for seals and bearings.
Anyway i have a quote of $2300 for a 3 blade stainless steel folding slipstream. Does anyone have any experience with them.
hes a great fellow to deal with ........... as he has probably told you the folder will only open to about 3/4 size in reverse ,so less power in reverse .
if you want good reverse power you will need to go feathering in slipstream props
That's prop porn I'm not happy with my fixed prop but I can't put a a new one on the list just now!
Hey Sands
When you say 3/4 in reverse how would that compare to a 2 blade. Would you say it would still be better.
Problem is I live in a state that gives crap service and keeps nothing in stock and everything comes from east and costs double.
The slipstream is the only folding prop i have been able to find on short notice. I guess i could haul out again or look at a diver later.
Select to expand quoteRiffRaff said..
Well talk about bring on another thousand.
I dropped the oil in the sail drive today and there was signs of water contamination.
I removed the bottom gear to replace the seals and noticed a couple of wear rings where the seals sit.
$900 for a new shaft and a couple more for seals and bearings.
Anyway i have a quote of $2300 for a 3 blade stainless steel folding slipstream. Does anyone have any experience with them.
Just looked at the slipstream folding system, it seems very similar to my Flexofold prop. The blade shape looks a little different to the Flexofold.
If you decide to go with the folding prop don't grease the folding gear during installation. I did that once and it caused the prop to start to fold when turning under power as the grease allowed the prop to fold too easily. It took about 2 months before the grease wore off and it return to normal operation.
While sailing I put it in gear which stops the prop from spinning and assists the folding
Im wondering. ...if somehow.
You could leave your prop turning ( at the risk of increase drag) but than use that force to turn a turbine that than creates electricity I can store or top up batteries with ?
Does that sound plausible or am I dreaming up another stupid idea ( Ive dreamt up a few stupid ones in my time 
)
A very good article from Yachting Monthly comparing folding and feathering props. I lean towards feathering props.
www.yachtingmonthly.com/gear/folding-and-feathering-propeller-test-29807
