Drill a whole in my shaft

[HarrisonM]

Hello:

I have a Beneteau and I recently lost my prop. Another is on order, but I am concerned due to they don't use a cotter pin. They use a folding over lock washer. I would feel much better if I had a cotter pin... The boat is in the water. I guess I would have to get a diver to do it, but can you drill a whole in the shaft while the boat is in the water to fit a cotter pin to it?

Thanks

[MikeHoncho]

I think I would consider if the previous system was installed correctly or not before that. Lifting it out, leaving it in the lift while you drill it must be cheaper than having someone dive on it with the right equipment to drill a hole underwater.

[steve77]

I'll jump in.

Offhand, I would say this would be very difficult to do in the water. In my opinion, drilling a hole in a prop shaft is a job for a machine shop. If it were my boat I would haul out, remove the shaft, and give it to a quality shop for the drilling. I wouldn't drill it myself on land, much less in the water. But that's me.

You can check around and see if any professionals offer this service. Maybe you'll find someone that can do it for you.

All the best.

Steve

[fstbttms]

Originally Posted by HarrisonM

Hello:

I have a Beneteau and I recently lost my prop. Another is on order, but I am concerned due to they don't use a cotter pin. They use a folding over lock washer. I would feel much better if I had a cotter pin... The boat is in the water. I guess I would have to get a diver to do it, but can you drill a whole in the shaft while the boat is in the water to fit a cotter pin to it?

I have done it underwater once (while installing a very old Max Prop) and vowed never to do it again. In your situation, it's an even worse idea. You have no exposed shaft in which a cotter pin could be run. You'd have to drill not only the shaft but the prop nut as well. These two holes would have to be perfectly aligned to insert the pin, any time it was replaced.

There is nothing inherently wrong with the French system. Your prop was likely lost due to a lack of maintenance, not because your boat doesn't use a cotter pin though the shaft.

[HarrisonM]

Thanks for comments guys

[Wotname]

Originally Posted by fstbttms

...........
There is nothing inherently wrong with the French system. Your prop was likely lost due to a lack of maintenance, not because your boat doesn't use a cotter pin though the shaft.

This ^^

Lock tab washers were quite common in older engines and vibrating mechanisms - they work.

[Compass790]

Originally Posted by Wotname

This ^^

Lock tab washers were quite common in older engines and vibrating mechanisms - they work.

Yes agree with Wottie.
Locktab washer seems to hold the flywheel nut ok on our single cylinder yanmar & that little engine can shake anything loose.
Its a bear to drill an ss shaft, hate to try it underwater.

[Jim Cate]

Finally, consider that there are literally thousands of Bennies happily motoring around with intact props. I am pretty sure that your loss was due to the tab(s) not being properly bent over whenever the prop was last installed, not a basic fault in the system.

Jim

[RaymondR]

There is one thing about drilling it under water. Whoever you find to do the job is not going to have a problem keeping the bit cool.

[taxwizz]

Hi Harrison;
Do you mean a "hole"?
Just wondering.
Are you drilling a whole hole, or just a part hole?

[Pitchondesign]

A prop needs to be lapped to the shaft to insure a tight fit. Properly lapped, even a modestly tight nut and wing washer will never come off.

[HarrisonM]

Thanks again all. I am hoping to pull the boat out next year some bottom work. I will deal with the shaft then.

[wholybee]

About 2 months ago my diver noted that my cotter pin was damaged, photographed it, and replaced it.

Point being, cotter pins fail too. Whatever you use needs to be inspected and maintained.

[double u]

Originally Posted by taxwizz

Hi Harrison;
Do you mean a "hole"?
Just wondering.
Are you drilling a whole hole, or just a part hole?

(we'd have been the laughing stock of the whole (sic!) highschool with such a spelling mistake - & this NOT in an English speaking country...)
a well, explains some things about the USofA...

[sailingchiro]

I am not sure drilling a hole would be worth the trouble. It is next to impossible without a drill press. And if your arms get tired and wiggle alittle-then you risk breaking the drill bit and that is a pain to remove.

If you would like, take a stainless steel bar and try to drill through it with a cordless Dewalt. I have tried it once and vowed never to drill stainless without a drill press.

Much less time and expense to have a good diver check the prop nut and washer each month during cleaning.