Stern gland packing

[Saltram31]

I removed my original 30 year old packing which was 3 rings of 8mm. I tried replacing with 3 rings of 8mm graphite but was near impossible to get the 3rd ring fully inserted in to the nut. (could not even see the threads.) After inserting each ring, i tightened the nut to push the packing to the back,but still no go. Would it be ok to use 6mm for the last ring or maybe 6mm altogether?
TIA.

 

[jerrytug]

I removed my original 30 year old packing which was 3 rings of 8mm. I tried replacing with 3 rings of 8mm graphite but was near impossible to get the 3rd ring fully inserted in to the nut. (could not even see the threads.) After inserting each ring, i tightened the nut to push the packing to the back,but still no go. Would it be ok to use 6mm for the last ring or maybe 6mm altogether?
TIA.

Hi, the packing you removed would perhaps have been of imperial size, and squashed down over the years. Do you actually need the third ring?
If you managed to get 2 rings of 8mm in there, and you can give them a gentle squeeze without running out of thread, I would go with that for the moment, and monitor, don't overtighten it!
I know it's difficult to see what's happening in there, what boat is it, and Vyv Cox's website has some advive I believe.

 

[Saltram31]

Hi, the packing you removed would perhaps have been of imperial size, and squashed down over the years. Do you actually need the third ring?
If you managed to get 2 rings of 8mm in there, and you can give them a gentle squeeze without running out of thread, I would go with that for the moment, and monitor, don't overtighten it!
I know it's difficult to see what's happening in there, what boat is it, and Vyv Cox's website has some advive I believe.

Jerry, that might be a possibility regarding the imperial measurement but I have an idea the flux was fitted with the ring off the prop shaft. The boat is a Saltram. I have a lot of adjustment with only 2 rings so you might be right. I'll have a look at Vyv's site. Thanks.

 

[vyv_cox]

I very rarely come to these pages but currently kicking heels waiting for the wind to die down, and on wifi, I noticed your question. It is quite common to hammer packing a little to get it to fit, usually using 8 mm for a 7 mm annulus, for which packing is not made. In your case you could maybe hammer 6 mm packing to make something like 8 mm in the annulus, but considerably shorter than 8 mm in length. This would allow you to get many more turns in.

Packed glands are a long way from being rocket science. I recently repacked one that was entirely made of of very short lengths, nowhere near the right section, just shoved in to fill the gap. It did leak a bit but nowhere near as much as you might expect.

 

[Saltram31]

Having just repacked my stern gland, I found this well illustrated info for those that have not done it before.

http://www.pbase.com/mainecruising/stuffing_box&page=2

 

[NormanS]

The more rings, the better, so you would be better with three rings of 6mm hammered out to 8mm, than two rings of 8mm. As Vyv says, it's not rocket science, but a good method and not prone to sudden catastrophies. As you say, your previous packing lasted for 30 years.