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Help! Metric prop shaft creating road block! 1972 Dufour Arpege.

10K views 26 replies 11 participants last post by  sony2000 
#1 ·
I can't seem to find any local shops willing to deal with getting a prop to replace the one I lost over two weeks ago! Help. I don't think I can afford a new prop shaft, cutlass bearing, stern gland and coupling just to switch to a 1" prop shaft. And no one wants to venture a guess as to the right diameter and pitch to the prop without seeing the old one. Well, if I hadn't have lost the old one, I wouldn't need a new one!

I want to go sailing again. HELP!
Lawson
 
#2 ·
To find the correct pitch and diameter of the prop, engine horsepower and reduction gear ratio, and the direction of the prop are needed. The diameter of your shaft is another problem, but a minor one. If it is metric and you measure it very close to an inch the diameter is probably 25 mm.
 
#4 ·
It is indeed a 25mm shaft. That I know. And I can find a prop with 1 1/8 inch bore that I can fit a bore reducer bushing to go from 1 1/8 inch to 25mm. The problem is also finding the prop nuts. Any resources? My local (Tampa Bay) prop shops won't discuss this option. Saying the bushing is of questionable durability and they have no clue where to get the prop nuts and anodes for my 25mm shaft.

Thanks,
Lawson
 
#9 · (Edited)
My local (Tampa Bay) prop shops won't discuss this option. Saying the bushing is of questionable durability and they have no clue where to get the prop nuts and anodes for my 25mm shaft
The marinas are full of boats with metric running gear. What kind of two-bit prop shop can't even supply 25mm zincs? I would say you should consider buying a new 25mm prop & nuts directly from the manufacturer. Here two of the best:

Campbell Sailer
West by North Enterprises - Campbell Sailer

Michigan Wheel
Homepage

Here's a great source for zincs online:

BoatZincs.com
Metric Shaft Zinc Anodes
 
#6 · (Edited)
Well

A 25mm shaft is .984 So the real issue is the angle of taper they CUT were the prop mounted which in all likelyhood is going to be different than and inch shaft and result in a bad fit if you cant find a metric prop

If you look around a BIT you will find the standard tapers are a LOT different

 
#11 ·
OK. I'm giving up on the local prop shops. Base on the e-mails, I'm going to buy a used prop and take it to a regular machine shop and have them bore the prop for a ISO Metric Taper 10:1 on a 25mm shaft.

Should that work?
Or do I need to give them more info?
Where do I buy the metric prop nuts?

I've managed to figure out that the prop should be a 12 x 7 fixed three blade.

Thanks for the help so far.
Lawson
 
#12 ·
Well

I would really take the time and find a metric prop as they will have the nuts also and there is NO saying for sure it is that taper it is just what shows up as a standard when searching.

Having spent most of my life in a machine shop its not that simple to change the taper in and existing part
 
#13 ·
#14 · (Edited)
What about the ones Beneteau uses
+1 on not using a non-metric prop. The correct solution to your problem is to use the right prop. Anything else is a band-aide.

Regarding the Beneteau prop nuts; these are not standard prop nuts and require a special washer to secure the prop and nut. It does not use a cotter pin. You could use this nut, but why? They are not superior to the usual double nut and cotter pin setup.

I find it hard to believe that you cannot find a metric-bore prop and the nuts to go with it. These are not uncommon items and any prop shop worth its salt should be able to provide them with no trouble.
 
#15 ·
FastBottom,

Me too. I've done everything short of begging. There are three "reputable" shops in our area. None of them want to mess with it. I can't figure it out. I mean Beneteau, Jeanneau, Bavaria and Dufour to name a few all have metric setups, right? Just so I'm reading you right, You are opposed to the bore reducer bushing, Yes?

Thanks,
Lawson
 
#17 ·
I mean Beneteau, Jeanneau, Bavaria and Dufour to name a few all have metric setups, right? Just so I'm reading you right, You are opposed to the bore reducer bushing, Yes?
Metric running gear is very common. Nothing unusual about it.

While the bore reducer will probably work just fine, I'd be concerned about it insulating the prop from the shaft and the protection provided by the zincs mounted there.

There is no compelling reason to not use a prop designed to fit on your 25mm shaft.
 
#18 ·
Fast Bottoms,

You say, "There is no compelling reason to not use a prop designed to fit on your 25mm shaft." I agree. But no one I've talked to yet (about 30 different shops) knows where to get metric prop nuts. A couple are looking into it. And I can't find any online. Do you have any resources? Also, the anode will have to mount on the prop nut as there is only about 1/2 inch of exposed shaft available between where the prop ended and the stern tube begins.

See pic at:
http://isurus.mote.org/~lmitchell/4DufourArpege/acc54db7bc88b567b2500d3768eb73d0.jpg

Lawson
 
#19 ·
I just got off the phone with the manager of Bay Propeller, which is one of the largest prop repair facilities on the West Coast. He told me that metric-bore props are not something they sell! :eek: I am shocked. He said that you will likely not be able to find a new, metric-bore prop and that the bore reducer is the best way to go. I asked him about new nuts and he said they also would be hard to find, although they could fabricate something if push came to shove.

Well, I guess you learn something new every day. Maybe your best bet is to go with a larger standard prop and a bore reducer. Regarding the nut, you can buy the Beneteau prop nut and the zinc that goes on that. For additional protection, Boatzincs.com does sell limited clearance shaft zincs that will fit in the very small length of exposed shaft your boat has.
 
#21 ·
Sounds to me like a used shaft in SAE (US demenisions) is your best way to go, as it will give you much more in options as far as props and hardware. It may not be what you want to do, but lets look at what went wrong in the first place;
1. You lost all the hardware that holds on the prop
2. The zinc is no longer attached ?
3a. The prop fell off while under way ?
3b. The prop is gone.
5. The prop shaft is damaged ?
6. The prop shaft threads are damaged ?

Buy a shaft and prop and move on, and perhaps increase your mantinence on the shaft/prop/zinc assembly in the future.
Good luck

Kary
SV Mariah #49080
 
#24 ·
OK. Here's where I stand. I've ordered the 25mm prop nut, lock washer, and anode from Beneteau. ($50.00) I've been advised they'll fit. When they arrive, I'll go swimming to confirm fit. If that works out, I've found a 12 x 8 LH with a 1 1/8 inch bore ($200.00) and a bronze reducer bushing ($86.00) to take the bore down to 25mm. If it all works (we'll see) then I'm back out sailing for $386.00. Less than an new prop, new shaft, new cutlass bearing, new stuffing box and new coupling... say $900.00-$1,000.00

Wish me luck!
Lawson Mitchell
 
#26 ·
can you help me do you think?

hello i hope your well i wonder if you can help me,
do you still have the dufour arpege 30? i am looking to change the cutless bearing as ours has worn out. can you give me any advice on this please, and might you have any pictures.

thank you in advance

Richard
 
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