What's wrong with folding props ...

[Scott T-Bird]

I've talked about my need to change props to get a better match for the boat and have the ability to work the engine at higher rpms. I have a 2-blade fixed prop and want to exchange it for a 2-blade folding prop. In this forum, I've heard disparaging remarks about folding props (something about not working in reverse).

At the boat show, I decided on a Flexofold prop. I few comments from bystanders were nothing but raves for a folding prop. Is there any downside? It doesn't bother me to spend a few extra bucks for better performance, I just need to know that I will still have reverse!

 

[kloudie1]

Yup, you will still have reverse but you have to be agressive in the use of the throttle.. It will not reverse as well as it does now with the fixed prop, but once you learn that you need a good bit more RPM and need it fast, you'll be OK. They work fine in forward gear and while sailing.. They don't catch crab pots as well as a fixed or feathering prop either.

 

[Rick D]

Ditto, just a question of RPM. I have a geared Slipstream 2 blade. Reverse is not noticeably different than the fixed prop, except you need more RPM for a given thrust. And, make sure to pause in neutral between shifts to not 'bang' the folder.

BTW, I'd do it again in a flash. Huge difference in light air and improved pointing. What's not to like?

 

[saltygator]

I love my Martec! It does take a little more throttle in reverse, but the gain in sailing performance is huge! And I sail alot more than I back-up!

 

[Ross]

If you consider the mechanics involved a folding prop is fine but it opens by centrifugal force and running it in reverse will try to fold it so you must apply a bit more throttle. I like my fixed three blade but that is a preference based on my wants not on any advantage of one versus the other.

 

[Johnb]

I have a 3 blade flex-o-fold and consider it a big improvement.

1 It is a lot heavier than the fixed prop so I take a lot of care not to slam it from forward to reverse or vice versa. I figure you can shear the key and lose the prop that way.
2 The centrifugal force is amazing. If you go from motoring to sailing and just put it in neutral the prop will keep spinning until you either stop in the water or briefly put it in gear. Once it folds it satys stopped.
3 Aside from performance the whole debate about in gear, in neutral, less resistance spinning or not goes away.
4 Performance in reverse seems about as good as my old fixed prop. Prop walk is about the same.
5 I laid in a stash of zincs and re order when I have used the last one - you can't get them off the shelf.

 

[Paul Mermelstein]

I have the 3 blade Gori and have noticed major improvement while sailing (point higher and sail about a knot faster). The motoring experience is about the same as it was with a fixed prop. Reverse is not a problem. BTW, I echo everything said by Johnb.

 

[Ed Schenck]

Just goose it to make sure it unfolds and grabs in reverse. My prop walk actually was reduced with my 2-blade Flex-O-Fold. I now have the 3-blade on the new 3YM30.

 

[Larry14133]

Buy It!

I put the three bladed Flex-o -fold on my boat two seasons ago. The boat sails faster, motors faster and backs better than with the fixed two bladed prop. It will go from hull speed to a stop in one boat length.

Regards,

Larry

 

[Don12364]

No Brakes??

If motoring ahead and you wish to stop then, as soon as the engine is put into neutral the water flow over the prop immediately causes it to fold. Then, as astern is engaged, this same flow tends to prevent the blades from opening again. Centrifugal force is minimal when the prop is closed and only comes fully into play after the prop has opened - and when it does open it often does so with a bang.
To get round this they try to make the blade tips heavy.

I had one which appeared to be good in normal maneuvering until I tried stopping suddenly - like when heading straight for the quay wall! That was when its vice showed and it did nothing more than make a froth which emerged from under the stern as we carried on forwards towards our eventual doom.

I bought a feathering prop and have never had anything else on any of my boats since then (and damn the expense).

If motoring in open water and an emergency stop is urgently needed - forget it.
I am sure that others will tell you otherwise.

I guess its your call.

 

[Scott T-Bird]

Thanks for the comments!

I am happy to hear all the pros and cons!

 

[Paul Mermelstein]

Re: Thanks for the comments!

Interesting comment from Donalex about folding props not opening in a panic stop. I have not experienced that. Maybe it depends upon the specific prop design (2 versus 3 blade, or geared versus plain hinged, etc.).

 

[Tim R.]

The 2 blade flexofold on both my Pearson 28 and my Ericson 35 improved performance in reverse over the fixed 2 blade.

I highly recommend them and Chuck Engel is great to work with.

 

[Ed Schenck]

Donalex is wrong, at least about the Flex-O-Fold. In neutral the prop will remain open. And you will know it because, if quietly sailing without the VHF or tunes blaring, you will hear the shaft turning. It won't fold until you go into reverse without power applied.

 

[Gail R]

I love my Martec! It does take a little more throttle in reverse, but the gain in sailing performance is huge! And I sail alot more than I back-up!

We have a two-blade folding martec on our Pearson 30. Well worth it to have better sailing performance and we can make the boat go backwards on the few occasions it's necessary.

I'm intriged by the one post indicating you'll have "no brakes" with a folding prop. The hard and fast rule on our boat, especially when manuervering in tight quarters, is "don't go any faster than you'd want to hit something." IOW, learn to manuver your boat, keep your speed down, and you don't need "brakes" for an "emergency stop." Following this mindset, we rarely hit something and on the occasion we do, it's just an incidental tap and nothing to get panicked about.

 

[mark_swart]

Scott -- don't think twice about the cons of a folding prop. You just have to give it a little more throttle in reverse. I've had them on my last two boats and love them.
Don't know if you've purchased yet but you can sometimes find great deals on them on ebay too if you know your size and pitch. Martec sells new pins for them so you can basically recondition a used one yourself. And they also offer the service.
Hope you enjoy the extra 1/2 knot of boatspeed!

 

[Blitz]

Donalex is wrong, at least about the Flex-O-Fold. In neutral the prop will remain open. And you will know it because, if quietly sailing without the VHF or tunes blaring, you will hear the shaft turning. It won't fold until you go into reverse without power applied.

I've never heard my prop shaft turning, but can see it if I open locker. Not sure if it is supposed to make noize.

 

[Clark]

Something I didn't see mentioned is that two-blade folders (in my experience) vibrate more. Also, as the pivot pins on mine wore, the vibration got worse. I loved how 'slippery' my geared Martec was when sailing but gave it up for a Campbell Sailor. The pin wear may have been a design issue since Martec no longer makes that prop. they now import a geared SS folder that is supposed to hold up better.

 

[Tim R.]

Both of my flexofolds would not fold until I engaged reverse. I usually hear it spinng when I acidentally left the tranny in N.

 

[Ron20324]

Both of my flexofolds would not fold until I engaged reverse. I usually hear it spinng when I acidentally left the tranny in N.

I get the same thing with my geared Gori 2- blade.