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?

Repack with real GFO packing and run dripless.

https://www.emarineinc.com/categories/GFO-Marine-Shaft-Packing

Re packing isn't a big deal. Just have someone who knows what they are doing help you the first time.

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!

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

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.

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.

Northern Spy said:

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.

Click to expand...

Good point. So with 2 1/4 shafts, do I also need to know the gland size to get new packing?

Alaskan Sea-Duction said:

...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.

"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?

FF said:

YES! When next hauled install a full set of the modern packing and it will be dripless.

Click to expand...

I agree with new over old if it is all going to be replaced at next haul out.

Alaskan Sea-Duction said:

Good point. So with 2 1/4 shafts, do I also need to know the gland size to get new packing?

Click to expand...

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.

Greetings,
Mr. ASD. Re-pack. I don't care what anyone says or claims, those "dripless" shaft seal do-dads are plum dangerous.

Alaskan Sea-Duction said:

...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...

Capt.Bill11 said:

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.

Click to expand...

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.

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?

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.

...and let us know how you make out?

Hawgwash said:

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?

Alaskan Sea-Duction said:

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.

Capt.Bill11 said:

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.

Click to expand...

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.

Tom, I'm going to PM you with the name of a Portland mechanic who I had come down to the boat one time when were down there for a few days. He's quick, he's good, and I felt he was reasonable.


Mike

Hawgwash said:

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.

Click to expand...

Not really meaning to argue, but many industrial pumps with deep packing glands have the first four or five rings retrofitted with a throat bushing made out of a plastic or resinous material because the packing really doesn't do anything but create drag and provide a minimal radial restriction.

I agree that if it is overcompressed and riding on the shaft, then it may cause wear.

If you get a mechanic to come to the boat, the apprentice idea is a good one. Packing maintainance is a good owner skill set to have.

I love drip-less shaft seals and who recommend installing them, BUT........

I would only take on their installation in conjunction with a known yard and with plenty of time to allow for things to go wrong or if the job expands. When you start digging into a drive line, you could easily find yourself replacing cutlass bearings, replacing a pitted shaft, rebalancing props, realigning engines, etc. etc. etc.. I'd want to be in a place and have time to deal with that if needed. You are on the move if I remember correctly, so I would NOT do it now, but rather wait until a better time/place.

For now, I'd just repack and keep going.

Capt.Bill11 said:

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.

Click to expand...

What is the expected life of Gore Tex GFO? That is if one were to repack with it, how long before repacking is again required?

Northern Spy said:

Not really meaning to argue, but many industrial pumps with deep packing glands have the first four or five rings retrofitted with a throat bushing made out of a plastic or resinous material because the packing really doesn't do anything but create drag and provide a minimal radial restriction.

I agree that if it is overcompressed and riding on the shaft, then it may cause wear.

If you get a mechanic to come to the boat, the apprentice idea is a good one. Packing maintainance is a good owner skill set to have.

Click to expand...

Aw, spy yer not arguing and I agree with you in the industrial setting where usually the mechanical people have a higher level of learning and experience than the average unknown bilge wrencher on a forum...not you Jim.

What's left of that little mill down the road from you, once had a million glands and I bet I packed every one up to #9 machine.

Professionally: I would just hire a local mechanic to repack the rings (and look over his shoulder on how to do it.)

Personally: I would install DSS. But the caveat with DSS is you MUST maintain the hose(s) and the rubber collar(s) every couple years. If you let the rubber seals go then the benefit of DSS is mitigated.

The original wax.ptfe rope shaft packing is just about goof proof. But it requires some maintenance. But the DSS requires less maintenance but more set up. The subject of repacking is about comfort and confidence in your ability to repack a bearing. If you loosen the packing locknut and nut and remove the gland, you may see a sudden flow of water. BUT you may not see an appreciable increase. If you have packing precut and stuff it into the gland, with one or two rings you will see the water inflow drop precipitously. If you are uncomfortable with the possibility, then hire a mechanic to assist you as mentioned.

I have used a diver to stuff wax rings around the cutlass bearing or through hull to stop the water inflow to ease the water pressure on the stuffingbox. BUT..... your confidence is what determines how you proceed.

The thread drift is indicative of another topic. If your packing gland is getting pretty close to bottoming out, then you should (prior to bottoming out) loosen and add more packing to bring the packing collar back out to flush. These packing glands are pretty basic in that they just need more rows of packing added prior to "NO" packing left.

Donsan said:

What is the expected life of Gore Tex GFO? That is if one were to repack with it, how long before repacking is again required?

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Don't know an exact number. But it's good for years and years. I seen it 5 years old and still looking and working just fine.

Donsan said:

What is the expected life of Gore GFO? That is if one were to repack with it, how long before repacking is again required?

Click to expand...

Who cares how long it lasts. The stuff is sold by the pound. You can stock up for YEARS for short money , if you are going to remote parts.
I think I would go for the Duramax instead , but that is only a personal choice.

Thanks. Got it. Will give him a call

I expected GFO on pumps to last 35000 hrs (4 years) running at shaft speeds of 1413 fpm.

So virtually forever on a recreational boat. Mines been in for over 7 years. Pre-engine swap, so a few hundred hours.