My prop fell off... f.ck f.ck f.ck.

[FamilyVan]

I think trying to fit a prop and key underwater in 10 meters sounds like a nightmare.

Oops dropped the key, swim down get key, oops, dropped the prop, swim down get the prop, oops dropped the key, swim down, can't find the key...

Surely sailing into the marina would be less stressful than that?

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[hoppy]

Right now the fat that I found my flexofold does not make me feel lucky. I am lucky that it fell off after I anchored the 2nd time and that I am so close to Athens, the marina etc...

Is there a standard sizing for the key? After SWL first comment, I'm starting to think I should take the dinghy to shore (a couple of resorts) and grab a taxi to the marina to find the key.

If I refit myself, I think I will just fit the original prop

Is this all I need, the prop, washer and nut (plus the key)



What tools will I need. A spanner for the nut, but what do I use to stop the shaft from turning? A vice grip? or perhaps the shaft has somewhere for another spanner?

[noelex 77]

Try sending a PM to Fsbttms. He must fit a lot of props underwater and may have some helpful tips.

[a64pilot]

I'd take the original prop with me and get a piece of key, it usually comes in bulk lengths like a 1/2 meter or so, and is very inexpensive. Take the prop as it's the only way to be sure, some keys are in inches, some in mm of course.
You'll need a spanner and usually just a piece of wood keeps the prop from turning, just jam the wood between the hull, rudder and prop, wood is soft and won't hurt anything and is cheap.
I wouldn't use the transmission to hold the prop by putting it in gear.
If your worried about dropping stuff, hang a big bucket off of the prop shaft to catch anything you drop, but I attach tools etc to me with a piece of line, we call it dummy cord, you know for when the dummy drops the spanner it's on the other end of the line

[hoppy]

Originally Posted by noelex 77

As I understand squeezing the prop against the tapered shaft is the mechanism that prevents the prop slipping. The key is (mostly) a back up.

Thus the key is not critical. Aluminium is easy to cut with hand tools. Can you cut a suitable key from a scrap piece of aluminium. If it was slightly undersized I don't think this would cause a problem short term.

If you do this keep the revs low.

I have a dremel with various cutting blades.

If it as you say, then that might be the best approach. Fit the fixed prop with a bodge job key. Sail to the marina and hope it holds out during the bething. Then get it fixed properly at the marina.

[a64pilot]

It's unlikely, but possible you could damage the shaft with a bodge key, seeing as the proper key is just a taxi ride away, why risk it?

[autumnbreeze27]

I'd be concerned that aluminum, being soft, could distort and be a real PITA to get off when you get the proper key.

Since you appear to have a good anchor set, I'd try to go get the part.

If you could get somebody to help you, you could possibly use the dinghy to get the boat in to a slip in the marina.

I once had a shaft pull out of a coupler. Pushed it back in and just never went in reverse again that trip. I had the key in it though.

[Pete7]

Have you got a file, the metal shaft that goes into the handle is likely to be a square taper which would be a start and could be cut with the dremel. After all you are not motoring far, just low revs into a marina. Measure the cut out in the old prop and estimate the same in the prop shaft.

Put a hammer in the bucket to weigh it down . When I changed a prop anode for Dockhead, I put the screws into the bucket then lifted the new anode out and the bucket inverted due to the weight of the metal handle with the screws disappearing into the depths Thankfully they were sat on the mud in 6m of water and the vis just good enough to see them. All sorted and Dockhead didn't need to know of the minor drama underwater.

The alternative is very much a MacGyver solution if you are good at metal work. Take a large stone of the beach, heat a spoon up on the cooker red hot and fashion into the right shape. S/S is soft are easy to shape. Trim with a file and hack saw. Not up to this, well what else has a square shaft on the boat? how about a sea cock, the handle is likely to have a square end. Got one that is above water that could be plugged with a bung?



Pete

[Pete7]

Originally Posted by autumnbreeze27

I'd be concerned that aluminum, being soft, could distort and be a real PITA to get off when you get the proper key..

True, but he is only going to motor slowly into a harbour and its not like its holding a flywheel on. As Noelex says, the taper holds the prop on, the key is just a back up or to provide exact alinement on a flywheel.

Pete

[weavis]

Originally Posted by Pete7

Thankfully they were sat on the mud in 6m of water and the vis just good enough to see them. All sorted and Dockhead didn't need to know of the minor drama underwater.

Pete

He does now!

[Cheechako]

You should be able to find suitable key stock from the hardware store or other. Square brass stock is available in 1/4, 5/16 and 3/8 usually. Just cut to length and deburr the cut ends. Make sure you don't make the key too long... the keyway in the shaft has a rounded bottom up to the outside diameter often, you want the key only on the flat bottom of the groove.

[fryewe]

Why did the prop fall off?

Positive attachment is often done by preventing the shaft nut from backing off by

-double nutting it (use of a second "jam" nut,) or
-use of a cotter pin through a hole in the shaft nut and shaft.

If the prop nut isn't retained in one of these or a similar manner, it will fall off again.

Fix it right, or take a chance on losing the prop.

[Delancey]

The Flex-O-Fold design uses a set screw to lock the shaft nut in place. As Training Wheels mentioned earlier this set screw is delivered from the factory with a special locking compound that works underwater.

I would be very interested to know how the prop fell off in the first place. Whether is was installed in or out of the water, whether the factory supplied set screw was used or resused, etc.

[hoppy]

Originally Posted by fryewe

Why did the prop fall off?

Positive attachment is often done by preventing the shaft nut from backing off by

-double nutting it (use of a second "jam" nut,) or
-use of a cotter pin through a hole in the shaft nut and shaft.

If the prop nut isn't retained in one of these or a similar manner, it will fall off again.

Fix it right, or take a chance on losing the prop.

No idea why at the moment.

The anode is still on the prop, so I assume that the nut is still there inside. I haven't had the energy to look at it, feeling a bit stressed and happy to still have the original prop.

Does not look to be any pins or anything adding extra security

[hoppy]

Originally Posted by Delancey

The Flex-O-Fold design uses a set screw to lock the shaft nut in place. As Training Wheels mentioned earlier this set screw is delivered from the factory with a special locking compound that works underwater.

I would be very interested to know how the prop fell off in the first place. Whether is was installed in or out of the water, whether the factory supplied set screw was used or resused, etc.

It was installed out of the water. No idea if they did it right at the time.