Go Back   Cruiser Log World Cruising & Sailing Forums > Cruising Forums > The Bosun's Locker > Engines | Propulsion | Generators
Cruiser Wiki

Join Cruiser Log Today

Reply
 
Thread Tools Search this Thread Display Modes
 
Old 09-25-2009, 05:29 PM   #1
Admiral
 
atavist's Avatar
 
Join Date: Jan 2007
Vessel Name: Persevate
Posts: 548
Send a message via Yahoo to atavist
Default

I've been doing a lot of motoring lately and within the last week I noticed that my stuffing box, which is of fortunately easily visible in the bilges under the V drive has started to leak, about 1 drop every 5 seconds....

Theoretically I know how to fix this. Back off the lock nut and tighten the packing nut a bit till it stops dripping run the engine make sure it stays cool, is dripping maybe a drop every couple minutes tighten the lock nut back down...

but on initial inspection there does't appear to be a lock nut... just one nut with two seperate purchases (Picture posted) I use a pipe wrench and a packing nut wrench and tried to break it apart as if it's two nuts but no luck... it does appear to be one nut (strange... or isn't it??)... so I tried to get a purchase on the threaded b it and turn the nut as one nut... no luck... although I didn't try to hard, it's hard to get a purchase on the threaded section and the bit with the pipe and clamps twist when I do this which makes me uncomfortable (I don't want to break the pipe clamps loose or anything, then I'd have a much bigger problem on my hands).... after fiddling with it the stuffing box is now leaking a bit faster, about a drop a second...

any advice/recomendations appreciated.
Attached Images
File Type: jpg DSC00089.JPG (100.7 KB, 150 views)
__________________

__________________
“The world turns aside to let any man pass who knows where he is going.” (Epictetus 55 - 135 AD)

"To see new things, and live day to day, is better than wine or poppy, and fitter for a man." (Theseus)
atavist is offline   Reply With Quote
Old 09-25-2009, 09:48 PM   #2
Retired Mod
 
Lighthouse's Avatar
 
Join Date: Mar 2007
Home Port: Durban
Posts: 2,984
Default

Related topic HERE
__________________

__________________


The World Cruising & Sailing Wiki

Help to build this free, online World Cruising Guide.

"Built by cruisers, for cruisers''

I've Contributed to the Cruisers Wiki: Most sections
Lighthouse is offline   Reply With Quote
Old 09-25-2009, 11:03 PM   #3
Lieutenant
 
Join Date: Sep 2008
Posts: 41
Post

You most definitely have 2 nuts there, one to lock the other. If you look closely you see that the flats on the hexagons are out of line with each other, no way could that be manufactured as one nut. Problem is to unlock these, you might like to apply heat, not too hot, try an elecric heat gun for stripping paint, works well and is useable in confined spaces such as where your stern tube is. Dont forget: unscrew in anticlockwise direction. also apply WD40 or similar, though not at the same time as heating! Put an extention tube on your wrench handle for extre leverage. Good luck, it is 2 nuts so go for it!
__________________
alan is offline   Reply With Quote
Old 09-26-2009, 02:24 AM   #4
Admiral
 
MMNETSEA's Avatar
 
Join Date: Oct 2004
Posts: 3,067
Default

What is equally important is to prepare what you MAY need (or WILL need) once the outer cap nut is removed.

What packing will you find ? What size and section is it ?What's it made of ? what's it lubricated with?

It might be useful to to measure the O/D of the shaft, the O/D of that part of the Cap-Nut that contains the packing ? the answer will give a rough measurement of the packing Diameter -= - a pure guess 5/16" square section need about a foot long with 3 turns , each of around 3"1/4" long.

What packing material ? One has to consider dissimilar Metals :- S/S Shaft, Bronze Cap-Nut etc.

Will the packing need a lubricant? If so, this will depend on the packing material.

Once the Packing cap nut is loose and moved forward on the shaft, then prepare to stem the sea invading the bilge, Long length of cloth wound tightly round the shaft aft of the cap nut and clamped with vice grips or hoseclamp etc, while the old packing is removed ( a long sharp nail with hook on the end to pick out the packing carefully)

NB. sometimes the old packing can be used again by taking it out carefully . the laying it straight out then tapping it with a soft hammer until it takes on a new shape - then replacing it on the shaft with teflon grease.

The drip tiime, as little as possible, check the temperature of the nut and shaft after say 15 minutes running.

the open
__________________
MMNETSEA is offline   Reply With Quote
Old 09-26-2009, 03:06 AM   #5
Admiral
 
MMNETSEA's Avatar
 
Join Date: Oct 2004
Posts: 3,067
Default

Agree very hard to discern from the photo that we have 2 separate wrench faces. Just in case there are not, it might be better to use a Large pipe wrench - green arrow and ajustable on the Red. Note the mild corrosion blue arrow : the shaft should be cleaned off and very fine (1000 grit) waterproof paper used to polish the shaft before replace packing Stuffing_Box_2.jpg
__________________
MMNETSEA is offline   Reply With Quote
Old 09-26-2009, 04:05 AM   #6
Lieutenant
 
Join Date: Jan 2008
Home Port: Hull
Vessel Name: Tadpole
Posts: 63
Default

I repacked my stuffing box 3 years ago whilst hauled out ... as well as size/thickness there are choices of material ... a. wax-lubricated hemp-type or b. teflon ... the wise old man of the boatyard said that "the wax/hemp option was the preferred choice as it can cope better with heat (most stuffing boxes run warm) the wax simply re-solidifies when drive is disengaged & the propshaft stops turning - thus doing double duty as both lubricant & sealant" ...

Loud cheer & round of applause for the previous post informing all of the method used whilst afloat ... although if tackling the job afloat I would humbly advise, before opening the stuffing box, a check of your existing bilge pump(s) & possibly adding to your pumpout capacity by renting or borrowing a gasoline/petrol-powered pump - or two) ... just in case ?

Also noticed in your pic that your propshaft appears to be rusting & showing signs of pitting just where it goes into the top nut ... when you have the stuffing box open reach for a wire brush to remove the rust & possibly a strip of emery cloth to ensure a return to shiny bare metal before reassemby ... if the pitting has bitten deep into the metal it may make it impossible to get an effective seal ...

Good Luck
__________________
svtadpole is offline   Reply With Quote
Old 09-26-2009, 08:40 AM   #7
Lieutenant
 
Join Date: Sep 2008
Posts: 41
Question

Atavist, reading your post again I see that the drip was 1 every 5 seconds, to my knowledge that is quite acceptable as the shaft does need some flow of water to remain cool. In my opinion your packing need not be removed, just tighten the nuts to regain 1 in 5 sec drips, or make it 1 in 8 or 10 secs if you like. I would not go to the extreme of removing packing while afloat and risk flooding for no reason. Remember, the packing is inside the body of the stuffing box, pick that packing out and nothing stops the water!

Logic tells me there is no way to stem the flow of water while removing old packing unless you do some shaft wrapping OUTSIDE the hull at the cutlas bearing.
__________________
alan is offline   Reply With Quote
Old 09-26-2009, 09:25 AM   #8
Admiral
 
MMNETSEA's Avatar
 
Join Date: Oct 2004
Posts: 3,067
Default

The photo shows a large Rubber Hose in which cold sea water is introduced via the cutlass bearing to ensure that this type of packed gland (not strictly "stuffing box") is kept cool. There are many types of prop shaft seals that exclude sea water totally - this one may also be designed to do that.

Dried salt is very slightly abrasive and may therefore scour the S/S shaft over time.
__________________
MMNETSEA is offline   Reply With Quote
Old 09-27-2009, 07:31 PM   #9
Admiral
 
atavist's Avatar
 
Join Date: Jan 2007
Vessel Name: Persevate
Posts: 548
Send a message via Yahoo to atavist
Default

Thanks for all the replies...

I'll try the WD40 and some more elbow greese and see if I can get them apart.... as recommended I'll probably not try to repack her afloat at the moment I'll just tighten it up a bit to slow the leak and then do a full disasembly/repacking when I get her on the hard in probably just a couple months.
__________________
“The world turns aside to let any man pass who knows where he is going.” (Epictetus 55 - 135 AD)

"To see new things, and live day to day, is better than wine or poppy, and fitter for a man." (Theseus)
atavist is offline   Reply With Quote
Old 01-13-2010, 05:05 AM   #10
Ensign
 
Join Date: Dec 2009
Posts: 39
Default

If you are going up on the hard soon anyway, consider a 'sure seal', an entirely dripless seal that we have used for years, they last nearly indefinitely and are very cost effective. We actually store crackers in the bilge, since there is never any water in it now. I change them every four years (we have 'copper coat' on the bottom and only haul out to check the skin fittings, rudder and cutlass bearings, etc. I hate haul outs as the risk to damage to the boat is so great while getting lifted and being out of the water) Tides Marine sells them, http://www.tidesmarine.com/shaft-seals.html and I have found them to be completely satisfactory and I am really picky and do not say that about much boat gear.

all the best!
__________________

__________________
Louiesails is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Installing Through-hulls & Repacking A Stuffing Box Lighthouse Repairs & Maintenance 20 09-14-2010 03:37 PM
Stuffing Box Sailboatman Repairs & Maintenance 7 05-08-2008 04:21 AM
The Yacht's Black Box Lighthouse General Cruising Forum 9 10-01-2007 05:37 AM
Furuno Radar Cable Junction Box? YachtVALHALLA General Cruising Forum 6 05-18-2006 07:55 AM

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

RV & Travel Trailer Communities

Our RV & Travel Trailer sites encompasses virtually all types of Recreational Vehicles, from brand-specific to general RV communities.

» More about our RV Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities


All times are GMT. The time now is 01:58 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.0