Shaft Log--CD36 redux

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M. R. Bober
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Joined: Feb 6th, '05, 08:59
Location: CARETAKER CD28 Flybridge Trawler

Shaft Log--CD36 redux

Post by M. R. Bober »

I just had a survey on a CD36. The aft end of the shaft log "disappears" into the fiberglass. The surveyor and I are concerned about the apparent absence of hose clamps on the aft end of the hose. The hose deflects under pressure so it would seem that there is not solid tube under it.

A quick search of this site show a few variations on the shaft log theme. CD must have secured the shaft log somehow. Does anyone know how they did it?

Thanks in advance,
Mitchell Bober
Sunny Lancaster (currently in the state of confusion), VA
CDSOA Founding Member
MFC
Posts: 405
Joined: Jun 3rd, '07, 07:53
Location: 1986 CD330
Hull No.128

Post by MFC »

Hi Mitchell -
Here's a shot of my old shaft log:

[img]http://lh4.ggpht.com/_2Lg5unxPjB8/Sm9zM ... %20028.JPG[/img]

You can see the marks from the buried hose clamps.


In this pic, you can see where the trailing edge broke out when the shoe was removed:

[img]http://lh5.ggpht.com/_2Lg5unxPjB8/Sm9zB ... %20027.JPG[/img]

That is in part because of the way this whole contraption went together. The shaft had no interior tubing -- simply the hose. At the aft end, it tied onto (by hose clamp) a bronze shoe that extended partway into the hull and accepted the aft end of the hose. That shoe is bolted onto the hull -- but poorly so IMO. It was done with lags on my 330. I replaced one of them with a carriage bolt and big washers inside. The lower bolt remains a lag for now because there is no good interior access (below the shaft) and I couldn't convince the yard to do this job as I wanted it done

By way of context: when I purchased the boat, I immediately hired the yard at the p/o's marina to replace the cutlass bearing. This grew into a reshaft, shaft log, etc etc etc. In the process numerous issues with the engineering of this part of the boat were revealed. That combined with the fact that the yard's work was atrocious -- despite its stellar reputation -- has left me with a number of nagging issues in this area. i suspect I will dig in there myself sooner rather than later to rework the entire job.

Hope some of that is useful. Good luck!

Matt
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Bill Cochrane
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Joined: Feb 5th, '05, 13:42
Location: Cape Dory 36 #114
s/v Phoenix

Post by Bill Cochrane »

Last year I had the yard install a dripless seal in place of the Spartan stuffing box. This was a bit of a major job...the shaft, shaft log, and cutless bearing were all replaced in the process.

<img width ="540"src="http://i52.photobucket.com/albums/g37/w ... oxBA-1.jpg" >

Before the change, the stuffing box hose was very tight against the aft end of the space, but there were double clamps on both the shaft log end and the stuffing box end. The aft end did sort of "disappear into the fiberglass"...not sure where else it would go!

<img width = "540" src = "http://i52.photobucket.com/albums/g37/w ... oxBA-2.jpg" >

The new shaft log is fiberglass; I'm not sure about the old one but would guess it was the same. Edit: after reading Matt's post, I can't be positive that the stuffing box hose was not connected to the bronze fitting, but on the new installation a fiberglass shaft log is clearly visible.

There are also two bolts, visible above and hidden below the shaft, that hold the bronze fitting on the outside of the hull which secures the cutless bearing. I believe both the shaft log and cutless bearing are friction fit; there is also a screw port and starboard, running athwartships, that penetrate the afore mentioned bronze fitting and secure the cutless bearing in place.
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M. R. Bober
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Location: CARETAKER CD28 Flybridge Trawler

Post by M. R. Bober »

Thanks to both of you.

Bill the aft end of the hose has no visible hose clamps nor is there room for any hence the "disappeared into the fiberglass" remark. Sorry I have no photos.

When I had to replace the shaft and cutlass bearing on RESPITE (CD330) the yard noted difficulty in the process due to a "hidden flat hose clamp" at the aft end of the shaft log.

Mitchell Bober
Sunny Lancaster (where adders can multiple on a log table), VA
CDSOA Founding Member
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Matt Cawthorne
Posts: 355
Joined: Mar 2nd, '05, 17:33
Location: CD 36, 1982
Hull # 79

Post by Matt Cawthorne »

Mitch,
There is no rubber hose on my boat. The stuffing box is threaded directly onto the bronze tube that holds the cutlas bearing. There just isn't room for the rubber hose, and the transmission and cutlass bearing are so close that there is not much opportunity for the shaft to wobble much. What this means is that if your engine is out of alignment, or the shaft is bent, the stuffing box will leak. Whether the engine shaking is enough to be a problem is up for debate. It does not seem to be for me. My boat is hull number 79. I am not certain why they never put a rubber hose on it. Perhaps they ran out of hoses that week and delivered it that way. My boat has more room between the coupling and the stuffing box than the pictures above.


Matt
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David van den Burgh
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Joined: Feb 5th, '05, 18:54
Location: Ariel CD36, 1979 - Lake Michigan
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Ditto

Post by David van den Burgh »

Matt Cawthorne wrote:Mitch,
There is no rubber hose on my boat. The stuffing box is threaded directly onto the bronze tube that holds the cutlas bearing. There just isn't room for the rubber hose, and the transmission and cutlass bearing are so close that there is not much opportunity for the shaft to wobble much. What this means is that if your engine is out of alignment, or the shaft is bent, the stuffing box will leak. Whether the engine shaking is enough to be a problem is up for debate. It does not seem to be for me. My boat is hull number 79. I am not certain why they never put a rubber hose on it. Perhaps they ran out of hoses that week and delivered it that way. My boat has more room between the coupling and the stuffing box than the pictures above.


Matt
FWIW, ditto Matt's reply. Ariel is hull #7.
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vjasinski
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Location: CD 33 #71
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Post by vjasinski »

When we replaced the hose on our CD 33, we found that the hose was connected to the stern tube with hydraulic style clamps. We had them installed at a shop that makes custom hydraulic hoses. The clamps were buried in the glass, and not visible until we removed the stern tube / hose assembly.
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