[Public-List] Close tolerances for shaft and shaft log! - Shaft Packing & Teflon Grease

John Birch Sunstone at cogeco.ca
Thu May 27 05:37:43 PDT 2010


Jeff,

If you haven't reinstalled the stuffing box and are using flax packing, may 
I suggest you buy some Davis White Teflon Grease and slather it on the 
packing before you install it.

Adding Teflon Grease to packing prevents burning or glazing the packing if 
you have a mechanical transmission with a lot of creep and hard to get true 
neutral.

I glazed the packing when I started the engine on the hard, which I do each 
spring, to get any AF out of the system before it goes in the water and to 
confirm the putt putt will actually putt putt and no be a burden to the 
club's launch crews.

One year I forgot to drizzle water down the shaft onto the stuffing box and 
wet the cutlass bearing. When I started the engine, it was not in full 
neutral and a whine started. I quickly shut it off. But when we launched the 
stuffing box leaked like a sieve.

Teflon Grease has prevented that from ever occurring again, but I still 
drizzle water down the shaft and wet the cutlass before test firing the 
engine on the hard.

The packing also lasts much longer too.

Just a suggestion.

Best

John

----- Original Message ----- 
From: "John Birch" <Sunstone at cogeco.ca>
To: "Alberg 30 Public List -- open to all" <public-list at lists.alberg30.org>
Sent: Thursday, May 27, 2010 8:14 AM
Subject: Re: [Public-List] Close tolerances for shaft and shaft log!


> Yea, Jeff,
>
> I don't think you have a big problem at all.
>
> In fact, on my old A30 the factory installed tube caused the stuffing box 
> to offset a bit because they didn't do as good a job as you apparently 
> have.
>
> As I said, suggest you try it for the summer and haul in the fall and sort 
> it out then if you are dissatisfied.
>
> If the shaft hits the tube that would mean it had bent over half an inch - 
> remember, you are talking thousandths of an inch when aligning - so you 
> shouldn't worry.
>
> Best
>
> John
>
>
> ----- Original Message ----- 
> From: "Jeffrey" <fongemie at gmail.com>
> To: "Alberg 30 Public List -- open to all" 
> <public-list at lists.alberg30.org>
> Sent: Thursday, May 27, 2010 8:03 AM
> Subject: Re: [Public-List] Close tolerances for shaft and shaft log!
>
>
>> Thanks John,
>>
>> My engine/shaft is aligned to .002 so there shouldn't be much wobble,
>> just the diesel shaking on the mounts. I've not used any Sikkens
>> products, but went with 4200 instead of the Dolfinite because I wanted
>> some adhesion and a little structural integrity to the sealant. For
>> such a big hole in the hull, a couple of lag bolts into fiberglass
>> does not seem that robust. Although, yes seems like the record for
>> Albergs sinking because of failed stern tubes is pretty good!
>>
>> For the stuffing box, I was thinking that the fitting would self-align
>> to the shaft, since it is on the end of a rubber hose it has the
>> ability to float somewhat.
>>
>> -Jeff
>>
>> On Thu, May 27, 2010 at 7:53 AM, John Birch <Sunstone at cogeco.ca> wrote:
>>> Hi Jeffrey,
>>>
>>> If you "fussed endlessly" ; ) aligning the shaft and the tube, 
>>> presumably
>>> the shaft is in pretty good alignment with the engine.
>>>
>>> The only concern might be how the stuffing box fits into the picture and
>>> it's impact.
>>>
>>> A slower cure like the Sikkens LOT caulks might have been a better 
>>> choice,
>>> but I would suggest you try it as it is and see if there really is an 
>>> issue.
>>> Not sure why you pulled the shaft log in the first place - the gray
>>> Dolphinite last virtually forever and remains pliable. Dolfinite is 
>>> still
>>> available by the way.
>>>
>>> As the shaft is short, I wouldn't worry about it hitting the pipe, the 
>>> boat
>>> would shake apart if it bent that much.
>>>
>>> If you do elect to redo it, I would suggest using Dolphinite as it has 
>>> been
>>> tried and true for decades and I haven't heard of any Albergs sinking
>>> because of a Dolphinite bond or aging failure.
>>>
>>> You can always haul in the Fall, and if you are up anywhere North, you 
>>> will
>>> anyway.
>>>
>>> Best
>>>
>>> John
>>>
>>>
>>>
>>> ----- Original Message ----- From: "Jeffrey" <fongemie at gmail.com>
>>> To: "Alberg 30 Public List -- open to all" 
>>> <public-list at lists.alberg30.org>
>>> Sent: Thursday, May 27, 2010 7:35 AM
>>> Subject: [Public-List] Close tolerances for shaft and shaft log!
>>>
>>>
>>>> Hey everyone,
>>>>
>>>> What began as a simple cutlass bearing change grew into a drive system
>>>> overhaul!
>>>>
>>>> I've got a new coupling, shaft and prop.
>>>>
>>>> see:
>>>> http://picasaweb.google.com/lh/photo/rBUX3ltoRI_YWDpiM4lFvQ?feat=directlink
>>>>
>>>>
>>>> Quite a job getting the old caulking out to reinstall the shaft log.
>>>> One thing that bothers me somewhat are the close tolerances between
>>>> the shaft log and drive shaft. On my boat at least, the id of the tube
>>>> is only 1 3/16". Not much clearance for a 7/8 shaft! In reinstalling
>>>> the shaft log, I fussed endlessly to get the alignment perfect, only
>>>> to find the shaft slightly off center once the 4200 sealant had cured.
>>>> I'm about a 16th off.
>>>>
>>>> See:
>>>> http://picasaweb.google.com/lh/photo/pfwCm_WcyK5tlVhWRz_7ZA?feat=directlink
>>>>
>>>> At this point, the sealant has cured & I need to decide if I'm close
>>>> enough. One thing I was thinking I could do to try to correct the
>>>> alignment would be back the two bolts outside the boat, using an old
>>>> chisel slightly crack an edge of the outside stern tube, stuff a
>>>> sliver of bronze under one side to re-align the tube and smear some
>>>> more 4200 into the crack before tightening down the bolts.
>>>>
>>>> Or I might just leave it.
>>>>
>>>> Jeff Fongemie
>>>> #116 Seagrass
>>>>
>>>> http://picasaweb.google.com/fongemie
>>>> _______________________________________________
>>>> These businesses support your Association:
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>>>>
>>>
>>>
>>> _______________________________________________
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>>
>>
>>
>> -- 
>> Jeffrey Fongemie
>> _______________________________________________
>> These businesses support your Association:
>> http://www.alberg30.org/store/A30supporters.html
>> Please support them.
>> _______________________________________________
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>>
>
>
> _______________________________________________
> These businesses support your Association:
> http://www.alberg30.org/store/A30supporters.html
> Please support them.
> _______________________________________________
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