Packing Size?

[Tink]

I have a 43 Gulfstar MK I and I need to know if any of you know what size packing goes in a 1 1/4" packing gland. Mine is in shreds and hoped one of you has done this recently. Thanks!

 

[eyschulman]

If boat is on hard use a ruler or caliper and measure the space.

 

[Alaskan Sea-Duction]

I used a piece of cardboard. Measure a 1 inch space and cut it out, them 1 1/2 cutout, then 2 inch and so on. Use your new gage to find out what size shaft you have and then cut buy the packing for that shaft diameter and follow the instuctions on how to cut it.

 

[Irish Rambler]

My boat had a standard packing gland but the po had just kept tightening it up and there was some slight wear on the shaft. I was able to turn the shaft end over end and I fitted a PSS seal, were very pleased with it and highly recommend it.
You can see the photo's at the start of my blog 'Windmills and Wine'.

 

[alormaria]

You can use a set of metal drill bits to determine the size of your packing. One will just fit, the next size won't.

 

[psneeld]

Make sure you lift or move the shaft a little to insure one measurement is the same all the way around.

If in doubt, go one size bigger in packing. Then before you install it, beat it flatter with a hammer, it will still slip in but plump up nicely when the gland is tightened.

 

[kapnd]

If your packing is in shreds, you need to do a careful inspection of the shaft in the area beneath the packing, it could well be damaged.
This often happens to boats left unused for long periods, in or out of the water.
Another good example of the benefits of regular fresh water flushing!

 

[CaptSteve53]

Do above checks, but the standard packing size for a common 1 1/4 shaft and accompanying bronze stuffing box is 1/4"size

 

[LaBomba]

Do above checks, but the standard packing size for a common 1 1/4 shaft and accompanying bronze stuffing box is 1/4"size

I agree, this is what I have, and is normal, but not guaranteed. I changed this year to Gore 100% GFO packing and adjusted it just once after installing and haven't had to adjust it since. At rest the packing does not leak at all and running almost nothing and it does not get hot. Great packing.

 

[Tink]

Thanks to everyone for the guidance. Ended up using 1/4" Teflon packing (PFTE?) since it was the only type available in Demopolis, AL. I put 3 strands in and still had plenty of threads remaining. There was a little shaft wear but nothing serious. Maybe I'll remove the shafts and have them reworked at the next bottom job in a couple of years.

 

[firstbase]

put 3 strands in and still had plenty of threads remaining.

If there are plenty of threads remaining, sufficient room, is it wise to put a fourth strand in or do benefits end at 3? Seems I remember reading somewhere on TF that an additional ring was a good idea if there was room...?

 

[psneeld]

If the water drip is where you want it (and the required amount of drip is often overstated with todays packing and slow turning engines).....

Really no need for another ring, but no harm either.

You can always add a ring later if you cant get rid of the drip while at the dock.

 

[LaBomba]

If the water drip is where you want it (and the required amount of drip is often overstated with todays packing and slow turning engines).....

Really no need for another ring, but no harm either.

You can always add a ring later if you cant get rid of the drip while at the dock.

I agree, good advice.

 

[CaptSteve53]

The normal recommendation by numerous packing gland manufacturers is 4 to 6 rings depending on the actual stuffing box design, only three quite often means you have to compress the packing's more to create a good seal, which can lead to premature shaft wear

 

[psneeld]

Assuming a few things like how much you had to tighten it with only 3.

 

[CaptSteve53]

Fully agree with that, the more packing's is more for the larger shafts, the smaller shafts are happy with 3-4 rings, it can also depend on how the rings are cut (square or taper cut),

These days with cheap laser temp guns it is a good idea to do a test run before tightening to much at all , then once happy with your results check with temp gun to be sure your running temp in the stuffing box is with in the "normal " range (which is approximately 30-40 f over the average sea temp) any more runs the risk of melting the lubricant out of the packing (dependent on type used),

As a side issue here I have been corresponding with Duramax company re an technical issue regarding their graphite packing, as many are aware ABYC recommend not using any thing Graphite in under water applications (packing/grease/ etc) as it's one of the most noble elements around ,Duramax's reply was is that the graphite is basically held in suspension and only in minor amounts therefore wont cause any issues,also noting the shaft zinc should take any negative effects away, They supplied technical data in way of an actual test report basically stating MINOR HEADLINE of whole report: Quote: the shafts were rotated at 25 RPM for eight hours each day and remained static for the remaining sixteen hours.?The samples were removed from the tank after 60 days and evaluated for corrosion. Under static and dynamic conditions, with zinc anode protection, both the Duramax Ultra-X® and the Flax packing exhibited the same degree of superficial corrosion «0.01 mm depth).

My only query would be the 25 RPM used as the test speed and was any stray electrical currents induced possibly inducing elevated Galvanic Corrosion issues, this has been a relevant issue for me as one of our 30 meter vessels using a graphite type packing developed a serious issue with in the Bronze stuffing box,TO BE CLEAR, I'm not saying it was Duramax how ever as our records are not that precise, Duramax them selves raised the point that there are numerous FAKE products out there trying to present them selves as the normally very respected Duramax products.

Just Saying, pays to be diligent!

Cheers Steve