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09-30-2015, 11:54 AM
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#1
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Guru
City: Inside Passage Summer/Columbia River Winter
Vessel Name: Alaskan Sea-Duction
Vessel Model: 1988 M/Y Camargue YachtFisher
Join Date: Jul 2012
Posts: 8,046
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RePack or Dripless Shaft Seals?
I have 2 1/4 inch shafts. They are packed with rope style seals. I was thinking of installing dripless seals. There is a significant cost associated with DSS.
My packing need replacement as the adjustment is almost bottomed out and my stbd side drips while parked and increases in flow when underway.
What are the pros and cons with DSS or should I just repack them?
I have never repacked the shaft seals and those I have talked too say it isn't hard job. I was worried about the amount of water when I back off the gland. No big deal? Should I pull the boat to do the job?
What say the TF experts?
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09-30-2015, 12:19 PM
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#2
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Guru
City: Sarasota/Ft. Lauderdale
Join Date: Apr 2014
Posts: 5,438
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Repack with real GFO packing and run dripless.
https://www.emarineinc.com/categorie...-Shaft-Packing
Re packing isn't a big deal. Just have someone who knows what they are doing help you the first time.
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09-30-2015, 12:20 PM
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#3
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Guru
City: Pender Harbour, BC
Vessel Name: Gwaii Haanas
Vessel Model: Custom Aluminum 52
Join Date: Sep 2013
Posts: 3,791
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Personally, I would do a quick-lift. If you have never re packed a shaft before, you will be a bit slow. If you've never packed it you should probably remove the old stuff first. The amount of water flowing in can be alarming and distracting. Also, if you haven't packed or serviced them the shafts might be scored.
Good luck!
__________________
Don't believe everything that you think.
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09-30-2015, 12:20 PM
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#4
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Guru
City: Everett
Vessel Name: LIBERTY
Vessel Model: TOLLY 48
Join Date: Mar 2013
Posts: 502
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Well, I'm far from an "expert", but here's my experience with exactly your conundrum.
My previous boat had 2" shafts, with conventional packing glands. It was easy-peasy to back off the packing nuts, twist out the old packing (using a purpose-made packing removal tool), and re-pack. Not positive of the exact product I used, but believe it was GTU Graftex Ultra-Shaft packing from Western Pacific Trading, which allows almost a leak-tight seal, both underway and at rest. All this while in the water.
Yup, water floods the boat while you work. Not as much as you'd think, and easily controllable with your bilge pump, assuming it's properly sized and working. Make sure you have the correct packing on hand before you start. Pre-cut the new packing to size before you begin, so you are ready to install ASAP the old stuff is reefed out. And have all your tools close at hand also.
If you haven't done this before, you may want to get a boatwright to do the first one while you watch, to glean any tricks of the trade I haven't mentioned. It should take about one hour per shaft, so you'd invest whatever the boatwright charged, but might be cheap insurance for your peace of mind.
My current boat has a PYI dripless seal on a single shaft, as well as the rudder post. No leaking on the driveshaft to date, but basically unserviceable in the water, either. My rudder shaft is leaking, and will have to wait for my next haulout to remove and R&R.
In my opinion, I would not replace conventional packing glands with dripless. They cost far more than they're worth.
Regards,
Pete
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09-30-2015, 12:52 PM
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#5
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Guru
City: Powell River, BC
Vessel Name: Northern Spy
Vessel Model: Nordic Tug 26
Join Date: Feb 2012
Posts: 4,073
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If the adjustment is just about bottomed out, why not just add another ring and snug back up? Approximately 70% of the sealing comes from the two rings closest to the gland follower anyways. The bottom rings are more or less spacers as they see very little compression.
Use a square braided yarn made of GFO or ePTFE.
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09-30-2015, 01:02 PM
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#6
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Guru
City: Sidney
Join Date: Feb 2015
Posts: 2,258
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Two things to be comfortable with for in the water repack are accessibility of the gland, which dictates time involved and reliability of your bilge pump.
How easy it is to get at the shaft area is up to you to decide but make sure your pump is capable of running near constantly for an hour without kicking out for some reason. You don't want the urgency of a failing pump in the middle of it all. Run a hose in the bilge for a while to see how it's handled.
The other important thing is staggering the packing ring joints as they go in.
I agree with the others that a knowledgeable helper who knows the tricks is a good idea, first time around. He will know from looking at what comes out, what might be left in and will also know how to "feel" the shaft with the removal hook. If it's been in there a long time I would definitely pull all the old stuff out.
Otherwise, not a big chore. Just damn cold on the hands at this time of year in our area.
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09-30-2015, 01:07 PM
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#7
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Guru
City: Inside Passage Summer/Columbia River Winter
Vessel Name: Alaskan Sea-Duction
Vessel Model: 1988 M/Y Camargue YachtFisher
Join Date: Jul 2012
Posts: 8,046
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Quote:
Originally Posted by Northern Spy
If the adjustment is just about bottomed out, why not just add another ring and snug back up? Approximately 70% of the sealing comes from the two rings closest to the gland follower anyways. The bottom rings are more or less spacers as they see very little compression.
Use a square braided yarn made of GFO or ePTFE.
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Good point. So with 2 1/4 shafts, do I also need to know the gland size to get new packing?
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09-30-2015, 01:34 PM
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#8
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Guru
City: Sidney
Join Date: Feb 2015
Posts: 2,258
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Quote:
Originally Posted by Alaskan Sea-Duction
...do I also need to know the gland size to get new packing?
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Measure the space between the shaft and gland nut (or chaser). If you do that, measure opposite sides as the shaft might not be centred perfectly. Or simply measure shaft OD and nut ID.
If you need to, go bigger on the packing and pound it a bit to fit rather than smaller hoping for compression to fill the space.
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09-30-2015, 01:59 PM
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#9
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Guru
Join Date: Oct 2007
Posts: 22,553
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"If the adjustment is just about bottomed out, why not just add another ring and snug back up? Approximately 70% of the sealing comes from the two rings closest to the gland follower anyways. The bottom rings are more or less spacers as they see very little compression."
YES!
Measure the packing by backing off , no the boat wont flood ,and use a back end of a drill to measure the packing size.
Then purchase Duramax or similar and install one or two rings.
When next hauled install a full set of the modern packing and it will be dripless.
The horror of the old style "dripless" packing was a thin bellows that could rupture and pass more water than any combination of pumps could handle.
They claim to have a new product , but there is ZERO danger with Gore or any of the new creations.
Why put the vessel at risk, when there is no need to?
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09-30-2015, 02:08 PM
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#10
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Guru
City: Sidney
Join Date: Feb 2015
Posts: 2,258
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Quote:
Originally Posted by FF
YES! When next hauled install a full set of the modern packing and it will be dripless.
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I agree with new over old if it is all going to be replaced at next haul out.
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09-30-2015, 02:29 PM
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#11
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Guru
City: Sarasota/Ft. Lauderdale
Join Date: Apr 2014
Posts: 5,438
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Quote:
Originally Posted by Alaskan Sea-Duction
Good point. So with 2 1/4 shafts, do I also need to know the gland size to get new packing?
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Use drill bits as feeler gauges to figure out the size packing you need.
I would just pull out all the old packing, repack with GFO and get it over with. Use the real Gore Tex GFO. There is a difference from all I've seen.
It's not a big deal and there is no reason to cheap out and just replace one ring of the old packing.
All the old, hard packing I've ever replaced all looked equally compressed. So I don't buy that the first rings get the most compression. Maybe in the beginning. But over time as the box gets re-tightened it seems they all get crushed and worn out.
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09-30-2015, 02:35 PM
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#12
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Enigma
City: Slicker?
Join Date: Oct 2007
Posts: 16,541
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Greetings,
Mr. ASD. Re-pack. I don't care what anyone says or claims, those "dripless" shaft seal do-dads are plum dangerous.
__________________
RTF
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09-30-2015, 02:39 PM
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#13
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TF Site Team
City: Jacksonville
Join Date: Nov 2008
Posts: 11,671
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Quote:
Originally Posted by Alaskan Sea-Duction
...I was thinking of installing dripless seals...
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I'd stick with what you have. It sounds like you're going back to AK. Haul out yards aren't as accessible as they are in the lower 48. It's hard to beat the old style stuffing box for reliability and with the new packing material...
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09-30-2015, 03:38 PM
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#14
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Guru
City: Powell River, BC
Vessel Name: Northern Spy
Vessel Model: Nordic Tug 26
Join Date: Feb 2012
Posts: 4,073
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Quote:
Originally Posted by Capt.Bill11
Use drill bits as feeler gauges to figure out the size packing you need.
I would just pull out all the old packing, repack with GFO and get it over with. Use the real Gore Tex GFO. There is a difference from all I've seen.
It's not a big deal and there is no reason to cheap out and just replace one ring of the old packing.
All the old, hard packing I've ever replaced all looked equally compressed. So I don't buy that the first rings get the most compression. Maybe in the beginning. But over time as the box gets re-tightened it seems they all get crushed and worn out.
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I would just pull it out and replace it too.
But as he expressed concerns in his abilities, it is a simple thing to gain confidence to add a ring which may very well fix his immediate problem. This will defer the maintainance of replacement until he is on the hard.
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09-30-2015, 04:00 PM
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#15
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Guru
City: Inside Passage Summer/Columbia River Winter
Vessel Name: Alaskan Sea-Duction
Vessel Model: 1988 M/Y Camargue YachtFisher
Join Date: Jul 2012
Posts: 8,046
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OK I am now convinced to repack. Should I seek out a yard to pull me out and repack it or have someone come to the boat and repack while in the water?
Can someone recommend a mechanic in the Portland OR area that would be willing to come out to the boat?
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09-30-2015, 04:15 PM
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#16
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Guru
City: Sidney
Join Date: Feb 2015
Posts: 2,258
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If it is easy to get at and the gland nut(s) moves easily, just leave it in the water. Pre cut the packing to length, pull the old, all of it, stick in the new one at a time and that's it.
If you want to pay someone else to do it just insist on being his apprentice for it to learn how and what tools to buy with the money you saved on no haul out.
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09-30-2015, 04:22 PM
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#17
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Guru
City: Pender Harbour, BC
Vessel Name: Gwaii Haanas
Vessel Model: Custom Aluminum 52
Join Date: Sep 2013
Posts: 3,791
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...and let us know how you make out?
__________________
Don't believe everything that you think.
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09-30-2015, 04:24 PM
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#18
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Guru
City: Inside Passage Summer/Columbia River Winter
Vessel Name: Alaskan Sea-Duction
Vessel Model: 1988 M/Y Camargue YachtFisher
Join Date: Jul 2012
Posts: 8,046
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Quote:
Originally Posted by Hawgwash
If it is easy to get at and the gland nut(s) moves easily, just leave it in the water. Pre cut the packing to length, pull the old, all of it, stick in the new one at a time and that's it.
If you want to pay someone else to do it just insist on being his apprentice for it to learn how and what tools to buy with the money you saved on no haul out.
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My gland nuts are easy to access and good suggestion on being an apprentice. Any recommendations for the Portland OR area?
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09-30-2015, 05:10 PM
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#19
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Guru
City: Sidney
Join Date: Feb 2015
Posts: 2,258
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Quote:
Originally Posted by Alaskan Sea-Duction
Any recommendations for the Portland OR area?
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Sorry no. I used to know a couple guys around Kelso but have lost touch.
There's probably a few old fishermen around there will do it for a dozen of their favourite.
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09-30-2015, 05:29 PM
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#20
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Guru
City: Sidney
Join Date: Feb 2015
Posts: 2,258
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Quote:
Originally Posted by Capt.Bill11
I would just pull out all the old packing, repack with GFO and get it over with.
It's not a big deal and there is no reason to cheap out and just replace one ring of the old packing.
All the old, hard packing I've ever replaced all looked equally compressed. So I don't buy that the first rings get the most compression. Maybe in the beginning. But over time as the box gets re-tightened it seems they all get crushed and worn out.
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I agree, Bill.
My concern with leaving any packing in there is that stuffing boxes tend to be forgotten about, until...
Who knows how long ago the existing packing was done and if it was all replaced and I've seen old packing get hard enough to score shafts.
It's a cheap fix, do it right. Right? Right.
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