# Folding Prop: How do I remove?



## rbrasi (Mar 21, 2011)

I'm trying to remove this prop, but there seem to be no noticeable nuts/bolts/cotters or anything with which to detach it from the shaft. Does anyone recognize this thing? It almost seems like it's one piece, but it can't be.... right?
The picture on the right is the opposite side of the one on the left.


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## KeelHaulin (Mar 7, 2006)

There should be some flats on the sides that you can put a wrench onto. I think these just thread onto where the prop nut normally goes; and are held on with torque the rotation forces keep it tightening when in forward.

You will need something to brace the driveshaft when you are turning the prop with a wrench. You might ask the yard what they normally use; or wait for an answer here. I don't want to give you the wrong advice on this.


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## Faster (Sep 13, 2005)

IIRC you need to remove the blades to get at the keeper on the shaft, and you'll likely need a puller for the hub even after you undo all that.

See here for an idea:

install_eliptec.gif


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## JimsCAL (May 23, 2007)

That's a Martec prop. Here's instructions on how to take it apart.

refurbish 2

I had mine refurbished this winter. Worth doing if the blades are "floppy" in the pivot pin.


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## rbrasi (Mar 21, 2011)

Excellent stuff. I'll try this. Thanks!


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## olson34 (Oct 13, 2000)

*Correct Description*

It may be a Martec brand. What it is NOT is a feathering prop. Totally different animal.
Looks like a _folding_ prop.

L


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## Faster (Sep 13, 2005)

olson34 said:


> It may be a Martec brand. What it is NOT is a feathering prop. Totally different animal.
> Looks like a _folding_ prop.
> 
> L


You're right, of course.... I've fixed the title for the OP.....


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## rbrasi (Mar 21, 2011)

Thanks for the semantic correction. Enlighten me please- what's the difference between a 'feathering' and 'folding' prop?


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## overbored (Oct 8, 2010)

rbrasi said:


> Thanks for the semantic correction. Enlighten me please- what's the difference between a 'feathering' and 'folding' prop?


A feathering prop the blades can be aligned so they do not cause drag. aligned with the direction of water flow. folding props the blades fold back in trail to the direction of travel.


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## Fstbttms (Feb 25, 2003)

rbrasi said:


> Thanks for the semantic correction. Enlighten me please- what's the difference between a 'feathering' and 'folding' prop?


Not semantics. Apples and oranges.


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## rbrasi (Mar 21, 2011)

Fstbttms said:


> Not semantics. Apples and oranges.


If they were as different as apples and oranges, why am I still not clear? "Aligned with the direction of the water" and "fold back in trail to the direction of travel" sound pretty similar to me. I'm new to all this, so tell me- how many types of props are there that are not fixed that would be of use on a sailboat, and what are their characteristics?


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## olson34 (Oct 13, 2000)

rbrasi said:


> If they were as different as apples and oranges, why am I still not clear? "Aligned with the direction of the water" and "fold back in trail to the direction of travel" sound pretty similar to me. I'm new to all this, so tell me- how many types of props are there that are not fixed that would be of use on a sailboat, and what are their characteristics?


Sometimes it helps to see both types illustrated.
One vendor that sells both Feathering props and Folding props is Martec. (Other products are equally fine, FWIW.)

Martec Propellers · Products

L


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## Fstbttms (Feb 25, 2003)

rbrasi said:


> If they were as different as apples and oranges, why am I still not clear? "Aligned with the direction of the water" and "fold back in trail to the direction of travel" sound pretty similar to me. I'm new to all this, so tell me- how many types of props are there that are not fixed that would be of use on a sailboat, and what are their characteristics?


Folding prop- blades simply flip out to an open position when prop shaft spins and fold back to a closed position when it doesn't.

Feathering prop- blades rotate on an axis or "feather" to align with direction of water flow when prop shaft is not spinning. When it does spin, the blades move into a preset pitch position. The pitch is typically adjustable, however.

Self-pitching prop- somewhat similar to a feathering prop, blades are shaped so that they move into the optimum pitch position when the shaft is turning and this changes with RPM. When the shaft is not spinning, the blades fall into a feathered position.


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## Faster (Sep 13, 2005)

... not to mention the 2 to 3 times price factor of feathering vs folding!!

Here's another shot at the difference... A folding prop is similar to you either doing the splits or putting your ankles together. A feathering prop is like you holding your hand out the window on a fast drive down the road and rotating your hand to in-line (the point of least drag) with the breeze .


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## rbrasi (Mar 21, 2011)

Awesome! Thanks, all!


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## Hudsonian (Apr 3, 2008)

You may need to use a bearing puller to remove the prop hub. I've been unable to fit two and three jaw gear pullers between the prop hub and the strut. A bearing puller made a world of difference.


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## JimsCAL (May 23, 2007)

Hudsonian said:


> You may need to use a bearing puller to remove the prop hub. I've been unable to fit two and three jaw gear pullers between the prop hub and the strut. A bearing puller made a world of difference.


You will almost certainly need a puller of some kind. I removed my Martec prop last fall and was able to get a C-clamp to apply some pressure, then one tap with a hammer and it was off. A puller would have been better than the C-clamp but I didn't have one that fit. Follow the instructions on the Martec site. Only loosen the nut, don't remove it completely as prop may "pop" when it releases from the taper. Mine sure did.


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## rbrasi (Mar 21, 2011)

Got it!
I used a 1/2" socket wrench extender to unscrew the nut, and I had to take it out completely to put the bearing puller in there against the aft end of the shaft. It took some doing, but, it worked. The prop did not shoot off or anything. The hardest part was getting the cotter pins out and making the puller grab on. We had to grind the ends to sharpen them. BTW- Harbor Freight sells them for $18. 
Thanks, as always to the vast knowledge data base that is SailNet!!!!!

PS- Does anyone want a Martec Folding Prop? I'm going to try a trade in for a fixed.


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## WoobaGooba (Oct 16, 2012)

JimsCAL said:


> You will almost certainly need a puller of some kind. I removed my Martec prop last fall and was able to get a C-clamp to apply some pressure, then one tap with a hammer and it was off. A puller would have been better than the C-clamp but I didn't have one that fit. Follow the instructions on the Martec site. Only loosen the nut, don't remove it completely as prop may "pop" when it releases from the taper. Mine sure did.


Hey JC

Got any pics? Struggling with this exact situation. Shaft is out of the boat.


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## Hudsonian (Apr 3, 2008)

Autozone will loan you a gear puller for free


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## JimsCAL (May 23, 2007)

WoobaGooba said:


> Hey JC
> 
> Got any pics? Struggling with this exact situation. Shaft is out of the boat.


Didn't take any pics. I think my post describes things pretty well. Feel free to ask any questions you have. A proper puller will really help.


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## Sanduskysailor (Aug 1, 2008)

Martec-
1. Remove the 2 cotter pins. Order new Monel ones from Martec.
2. Use 1/2" extension and ratchet to unscrew locking barrel nut.
3. Use block of wood and tap with hammer to remove barrel from prop shaft. A puller will work also if you have one. Soak prop with Blaster or Kroil if you are having trouble. Mine came off easily after removing nut which was really the hard part.

Trick for making sure Martec is closed. With boat out of the water hand rotate prop so that is stays in locked position. Mark prop shaft in boat, also rotate 180 degrees and mark that spot too.

In my experience the Martec will close to the right position if you turn off the engine then placing it immediately in gear at boat speeds of 5knots or more.


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## rbrasi (Mar 21, 2011)

Here is a picture from when I did this five years ago. I had to combine two gear pullers to make it long enough. Look closely and you'll see that I used bailing wire to snug it to the prop. I ended up keeping the Martec and she still works great to this day. I also still have the pullers, collecting dust in my storage!


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## Fstbttms (Feb 25, 2003)

Sanduskysailor said:


> Martec-
> 1. Remove the 2 cotter pins. Order new Monel ones from Martec.
> 2. Use 1/2" extension and ratchet to unscrew locking barrel nut.
> 3. Use block of wood and tap with hammer to remove barrel from prop shaft. A puller will work also if you have one. Soak prop with Blaster or Kroil if you are having trouble. Mine came off easily after removing nut which was really the hard part.
> ...


BTW- all of the above is also quite easily done underwater by a properly equipped diver. FYI.


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## cmack003 (Aug 28, 2018)

rbrasi said:


> Got it!
> I used a 1/2" socket wrench extender to unscrew the nut, and I had to take it out completely to put the bearing puller in there against the aft end of the shaft. It took some doing, but, it worked. The prop did not shoot off or anything. The hardest part was getting the cotter pins out and making the puller grab on. We had to grind the ends to sharpen them. BTW- Harbor Freight sells them for $18.
> Thanks, as always to the vast knowledge data base that is SailNet!!!!!
> 
> PS- Does anyone want a Martec Folding Prop? I'm going to try a trade in for a fixed.


Not sure how recent your post is but I have a fixed prop off an Atomic 4 /Universal diesel engine with 3/4 shaft....I need a Martec 13 DX elliptical shaped prop..what is your Martec you are trying to replace?
Colin


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## rbrasi (Mar 21, 2011)

Post #23 details how I ended up sticking with the Martec. I sold the fixed one and took a bath on that.


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