Stern gland adjustment

[ChrisReid]

Hi everyone, long time sailor first time stern gland fixer here.
I have a new to me Colvic Atlanta and have just repacked the stern gland stuffing box.
(Two bolt type with a water feed from engine).

Checked and used the correct size PTFE packing rope, installed the 3 rings and made sure the links are at opposing angles, roll compressed and not hammered etc… all the usual stuff advised in the manuals I have followed.

Advised to tighten until you can turn shaft by hand but drip reduces to 1-2 times/min.

Boat is in the yard at the moment and pending launch so doesn’t drip at all as not in the water.
How do I know how much to tighten without being too loose and peeing in water/sinking as soon as launched and not too tight burning out the shaft/packing on the way to the berth?

All advice on adjustment is for when already in the water,
how do you know pre launch whether it’s too loose or not?
Having never done this before and struggling to find info online, I’m completely at a loss here.
Any advice welcomed,
Many thanks in advance.

 

[Refueler]

You adjust once in water ... the amount of water ingress is small ...

My way - I'm sure others will give their opinion as well .... - is to pack ... and nip up to the packing .. then about a 1/4 - 1/3rd turn more. That's enough to press the packing but not enough to 'sqeeeeze' it .... Run the engine in gear and check for water drip rate......

When adjusting in water ... do not be too quick to tighten ... take it in small steps ... what you do not want to do - is tighten so it all stops. If that happens - then it will take time for packing to loosen after slacking back - in that time will possibly overheat.

 

[mattonthesea]

Another way is to tighten until you cannot turn the shaft by hand; and then turn back until you can. Worked for me.

As above, water ingress minimal. You can change the packing when afloat if you have everything ready! With packing in it will never be more than a slow dribble.

 

[ChrisReid]

Thanks guys, this is very reassuring, had visions of the trevi fountain in the engine bay.

 

[Boater Sam]

It will not be a flood even if very slack. We used to change the packing and even the bronze stern bearings whilst afloat.

 

[Rappey]

Ive changed my packing afloat. The amount of water with no packing is not that dramatic.
I would go for a motor once afloat to allow all to settle and then fine tune how tight.
A dentist like pick is ideal for hooking out the old packing.

 

[Poignard]

 

[ChrisReid]

View attachment 173645

That’s an extractor tool, has nothing to do with adjustment what so ever.

 

[Poignard]

That’s an extractor tool, has nothing to do with adjustment what so ever.

Thank you, I am perfectly well aware of that.

Perhaps you were unaware that I was responding to Rappey's post, the one immediately preceding mine?

 

[vyv_cox]

Changing packings while afloat it is of course best to have everything ready beforehand but in the event that something goes wrong a rag wrapped around the unpacked gland will almost totally stem the flow of water.