Gland packing size?

I assume that you are doing it out the water
Basically yes that is the required measurements
With great difficulty may well be the answer without stripping it but you could narrow it down some what and buy more than one size

Do you need to completely repack or would adding an extra ring work
 
Out of water indeed!

It seems to have been replaced at least once by a previous owner, but it's been a decade more since so i think it's wisest to replace. I'll try to get someone experienced to do it.

I think the rubber coupling may need doing too. Way beyond my pay grade...

Shaft log B-107.jpg
 
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There are only a few sizes in use.

You could order a length of each and return what you don't use.

But why not remove the packing nut and take a meaurement? Easy to measure by inserting drill bits and seeing which one fits best.
 
'remove the packing nut'
Nice idea, but wouldn't that flood the boat? :oops: It's currently in the water. South Dock's lock, which has a crane, is closed from Nov 9, so it's only out for a few days, and I'd like to have everything ready.
 
'remove the packing nut'
Nice idea, but wouldn't that flood the boat? :oops: It's currently in the water. South Dock's lock, which has a crane, is closed from Nov 9, so it's only out for a few days, and I'd like to have everything ready.
Very unlikely. But if you slowly remove the packing nut and water did start to come in in sufficient quantity to worry you, simply screw it back in.
But gland packing is usually firmly held in place and has to be extracted with a suitable tool .
 
You do not say what size the prop shaft is, for example if they are 25 mm dia the stuffing will probably be 6 mm or if 1" dia 1/4", however whatever you do I do not recommend you even think about doing it whilst afloat, as its not a five minute job and so may things can go wrong as Poigard above says you need to get ALL the old stuffing out before re packing which also takes time.

One tip is to count the number of stuffing ring you take 'out' so you know how many to put back 'in' and any joint cuts to the stuffing should be at 45 deg.and each stuffing ring joint offset to the next one
 
If you are going to get the hose assembly done at same time leave the gland packing it to the experts and and ask them to leave some extra packing
The rubber itself is not complicated but you will have to remove the gearbox coupling to get the hose over the shaft
 
Don't know your boat but there's another alternative and that's ditching the packing and going for one of the self-sealing rubber boots.

I forget the name/model of them. Volvo do one.

Think there are limits for use where overly flexible drives are involved. Would be interested in feedback as am considering myself.

volvo-seal-243x200.png
 
Radice also do them which I think are better - no need to 'burp' them when refloated, easier to grease them, and cheaper! Never leak either, much better than a traditional stuffing gland - imho...
 
If you use gland material that is too thick so that it engages the threads in the 'barrel' and has to be rammed in you will find it difficult to adjust and terrible to remove .Use a calliper to measure the shaft and the inside of the thread diameter.Squeezing the packing to reduce its thickness is no substitute.
As suggested on a You tube video you can cut a short length (2 -3 inch) of smooth bore flexible pipe (e.g. 1'' id ) with a square end ,slit and fit it over the shaft,and use it to push the rings in.
 
If you use gland material that is too thick so that it engages the threads in the 'barrel' and has to be rammed in you will find it difficult to adjust and terrible to remove .Use a calliper to measure the shaft and the inside of the thread diameter.Squeezing the packing to reduce its thickness is no substitute.
As suggested on a You tube video you can cut a short length (2 -3 inch) of smooth bore flexible pipe (e.g. 1'' id ) with a square end ,slit and fit it over the shaft,and use it to push the rings in.

I haven't come across a packed gland which has threads on the inside, they've always been plain surfaces. Altering the shape of the packing for easier clearance is fine, when it compresses it moulds to the space. Easy enough job to do afloat but maybe not for the first time, just cut and prepare new before removing old, push into place with a screwdriver, no need for a tool.
 
Remember to cut the rings of packing on an angle rather than butt joints. Normally more than one ring so stagger the joints. With my stuffing box a few shots of grease before removing the old packing allowed me to do it afloat. Getting the right compression to keep out water without the friction causing heat took a few adjustments over time. A good resource is Vyv Cox's website that taught me all I know about it, followed by having a go.
 
ChasB - I can't find the video giving the tip about this simple tool to push the rings in but here it is if you want to try it.I happened to have this 25mm id soft tube in the shed which matched my shaft.You can of course use any implement but having carefully cut my rings it made sense to push them in squarely rather than risk damage.IMG_20201029_105714420_HDR.jpg

There are numerous You Tube videos showing the repacking process although as mentioned above there is very clear guidance on VYV Cox's website ,including details of the variety of glands other the simple screwed version which I have.
 
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