Packing Gland

[John Lewis]

This is an old stern gear, which we had out and cleaned up.

 

Putting it back I cut three packing glands I think 5mm and wrapped around shaft - then slid stuffing box back on.

 

A few people have said to me there should be an extra packing rope sandwiched between the stuffing box where it tightens on. Is this right?

 

pic of stern gear attached

 

 

[Alan de Enfield]

 

 

Did you apply the 3 packing ropes with the cut ends at 120 degrees to each other ?

[David Mack]

There is virtually no clearance between the pusher and the body of the gland. Looks like there should be another 2 or 3 rings of packing in there. Have you got the right sized packing?

 

It should look more like this.

Edited April 1, 2021 by David Mack

[John Lewis]

I put three wraps in there.. over the shaft cut individually.

 

I was trying to squeeze grease down to fill the tube but its squirting out the engine side.

[David Mack]

2 minutes ago, John Lewis said:

I put three wraps in there.. over the shaft cut individually.

 

I was trying to squeeze grease down to fill the tube but its squirting out the engine side.

That suggests the packing is not tight and the pusher has bottomed out. More packing needed.

[Alan de Enfield]

6 minutes ago, John Lewis said:

I put three wraps in there.. over the shaft cut individually.

 

Did you align the ends so that each coil was 120 degrees 'out' to the next one ?

[Jen-in-Wellies]

2 minutes ago, David Mack said:

That suggests the packing is not tight and the pusher has bottomed out. More packing needed.

Possibly also that the packing diameter was too small. How did you select the packing size? Did you measure the gap it was to go in?

[John Lewis]

I remember the packing I used was pretty thin stuff. I got it from a guy locally who had a roll of it, but that could have been for sea going boats. Possibly the stuff I need should be thicker?

 

The stuff I put in was only 2mm thick come to think of it but 5mm in depth to take up the gap..

is this the right stuff?

https://www.ebay.co.uk/itm/Stern-Gland-Packing-Containing-PTFE-Silicone-Boat-Propellor-Shaft-Freepost/264736131820?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20160908105057%26meid%3D214c21e674b0470580d01bfd9fb12c42%26pid%3D100675%26rk%3D1%26rkt%3D15%26mehot%3Dnone%26sd%3D264736131820%26itm%3D264736131820%26pmt%3D1%26noa%3D1%26pg%3D2380057&_trksid=p2380057.c100675.m4236&_trkparms=pageci%3Ad1237bd3-92c8-11eb-adc5-9ac11e06d164|parentrq%3A8caa55121780ad3966ab7faaff9e83ed|iid%3A1

[matty40s]

Probably best to use 8mm packing, Fitbit to size and then gently flatten with a hammer until it can slide into the gap.

Make sure you remove all the thin stuff, as if it gets trapped between the prop shaft and stern gear, could wear the prop shaft thinner.

[David Mack]

You need to measure what size packing is needed for this particular stern gland. Previous thread:

 

[Flyboy]

16 minutes ago, John Lewis said:

I remember the packing I used was pretty thin stuff. I got it from a guy locally who had a roll of it, but that could have been for sea going boats. Possibly the stuff I need should be thicker?

 

The stuff I put in was only 2mm thick come to think of it but 5mm in depth to take up the gap..

2mm is way too thin. 

 

 

Edited April 1, 2021 by Flyboy

[Jen-in-Wellies]

11 minutes ago, matty40s said:

and then gently flatten with a hammer

This instruction is applicable to so much in life, not just stern gland packing.
?

 

[Slim]

An easy way to measure the size of packing required is to use a drill bit. (shank end) as a go / no go gauge

[John Lewis]

Ok, cheers all.

[Bee]

The 'pusher' that squeezes the packing is right up against the body of the thing, I'm sure there are proper names for them, that would usually indicate no packing, i expect the packing is too thin, has been shoved down the tube and the grease is finding the easy way out. 

[bizzard]

I'd get that packing out NOW!! and fit the correct diameter stuff before it's shoved down into the bearing and jambs the shaft up solid, if it hasn't already.

[ditchcrawler]

1 hour ago, John Lewis said:

I remember the packing I used was pretty thin stuff. I got it from a guy locally who had a roll of it, but that could have been for sea going boats. Possibly the stuff I need should be thicker?

 

The stuff I put in was only 2mm thick come to think of it but 5mm in depth to take up the gap..

is this the right stuff?

https://www.ebay.co.uk/itm/Stern-Gland-Packing-Containing-PTFE-Silicone-Boat-Propellor-Shaft-Freepost/264736131820?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20160908105057%26meid%3D214c21e674b0470580d01bfd9fb12c42%26pid%3D100675%26rk%3D1%26rkt%3D15%26mehot%3Dnone%26sd%3D264736131820%26itm%3D264736131820%26pmt%3D1%26noa%3D1%26pg%3D2380057&_trksid=p2380057.c100675.m4236&_trkparms=pageci%3Ad1237bd3-92c8-11eb-adc5-9ac11e06d164|parentrq%3A8caa55121780ad3966ab7faaff9e83ed|iid%3A1

How long a piece do you get for £14  Look here https://www.asap-supplies.com/products/drive-force-ptfe-flax-sturntite-gland-packing-8mm-1-metre-coil-807541

 

[John Lewis]

Heres the stuff I had put in...

 

 

looks to be about 3mm or 3.5mm thick.. 5mm Deep

[John Lewis]

8mm seems to be the ticket.

[Slim]

27 minutes ago, John Lewis said:

Heres the stuff I had put in...

 

 

looks to be about 3mm or 3.5mm thick.. 5mm Deep

I think you're confusing depth and thickness. Looking at your photo the important measurement is the 'left to right', the bit your screw has gone into. Assuming the woodscrew is 4 mm that bit of packing is around 6mm. Think polo mint  the measurement between the hole and the outside edge would , in packing terms , be described as the thickness. 

 

Just read your latest post , good.  

 

     

Edited April 1, 2021 by Slim

[ditchcrawler]

An easy way to check is to slide an 8mm drill bit into the housing down the side of the shaft. You will soon see if its 6 or 8 mm

[D Ash]

On 01/04/2021 at 09:56, Alan de Enfield said:

 

Did you align the ends so that each coil was 120 degrees 'out' to the next one ?

In the video demonstration the guy cut at 90 degrees   Is this where you mean the cut to be 120 degrees?

 

[Tony Brooks]

9 minutes ago, D Ash said:

In the video demonstration the guy cut at 90 degrees   Is this where you mean the cut to be 120 degrees?

 

I think he means each ring of packing should be twisted through 120 degrees so the joints are not all in line. A scarfed cut might be better but a 90 degree one may be cleaner and less frayed.

[D Ash]

2 minutes ago, Tony Brooks said:

I think he means each ring of packing should be twisted through 120 degrees so the joints are not all in line. A scarfed cut might be better but a 90 degree one may be cleaner and less frayed.

Yes , I see what you mean.  Just re-read Alan's advice and that certainly seems what he is implying.

Would the "cut at +/-120 degrees" also be a good idea?  a bit like railway tracks 

[David Mack]

17 minutes ago, D Ash said:

In the video demonstration the guy cut at 90 degrees   Is this where you mean the cut to be 120 degrees?

 

The important point is that the joint in one ring of packing should not be anywhere near the joint in the adjacent ring(s). That way if there is a gap in the joints water can't just flow straight through. Whether the ring joints are spaced at 90 or 120 degrees is less of an issue. But most glands accommodate three rings of packing, hence the suggested 120 degree spacing.