Stuffing Box--No Water Through the Shaft Log

[Departing2017]

I'm helping friends repack a stuffing box with the boat in the water. From what I can gather, they tried to adjust the packing nut. When they ran the engine in gear, the stuffing box got hot. They saw at least 160F/71C with an IR thermometer before they shut down.

Following the overheating incident they tried to remove the packing nut, and it became stuck (I think what was left of the flax actually folded over on itself and wedged the nut to the shaft), so they asked me for help. I managed to work the nut free of the packing gland assembly and slide it up the shaft so I could clean the old packing material out. The packing was pretty much destroyed, and we had to pick it out of the nut one tiny piece at a time.

So here's the weird part. With the packing nut completely removed from the stuffing box there is no water coming through the shaft log. Am I having a brain fart here? Shouldn't the boat be sinking?

We don't know whether any water was getting to the packing before the incident; I assume not, which explains the overheating. Has anyone else run into this? What would plug up the shaft log so thoroughly that no water could come through? I dove the boat and the shaft orifice looks clean (the cutlass bearing rides in separate a strut). The shaft turns smoothly by hand. I'm at a loss.

I appreciate any shared wisdom here.

Thanks

[Sailmonkey]

It’s possible that some of the packing was shoved into the void between the gland and the shaft. Especially if the old broken down packing wasn’t removed prior to putting more material in.

[tkeithlu]

Sailmonkey speaks with wisdom. There really isn't any other place for the blockage to occur. Sounds like they badly overtightened the packing nut.

But, next:
Does the shaft overheat when run with just the stuffing that is jammed in that small crack? If not, you may be able to loosely fill the stuffing box, add the nut, and protect the boat against a major leak should the small stuff comes loose unexpectedly. If it does overheat, then it's got to come out, and it is hard to imagine any way to do that other than lifting the boat and pulling the shaft. The stuff is going to be too tightly in there and in too small a space to push or pull with the shaft there.

I did something almost this bad to a fire engine pump in the 1980s. Fortunately, it all came out when I used a tool like a miniature corkscrew to grab it. It's darned easy when tightening a stuffing box, if you are as inexperienced as I was, to tighten it too much. You want it to leak, just not very much, and it's a difficult balance to achieve. I've moved on to shaft seals. If you have to pull the shaft, consider a seal such as these to be a good investment:

https://www.deepblueyachtsupply.com/...MaAizJEALw_wcB

Good luck with it. Your friends are fortunate to have your help.

[Manateeman]

I agree with Sailmonkey. Sometimes little tube worms grow in that space and they leave a hard shell stuck on the surface of the shaft and the shaft log and it will sort of grab the packing. Kinda like the packing is between two rasps.
Can you can move the shaft forward or back ...so you can see what’s going on in the area where the packing sits? Then you might be able to polish the shaft and clean the shaft log. Silly question but the right size packing?
I have a last drop but for regular packing I use the Teflon stuff.
For tools, I use Stainless TIG rods. Don’t break anything inside!
Does the shaft sit correctly inside the shaft log. Once I saw a fiberglass shaft log that was improperly laid up with not enough resin actually start to self destruct and wound itself around the shaft and break loose from the hull. That almost sunk us. You have got to get water to the packing.
Remember the weight of the prop pushing down. Any chance the shaft got bent.
Can you get the stuffing box off the shaft log. What’s the hose condition. Anything jammed in that space or is the stuffing box tight against the shaft log.
In some cases, there is a lot of space and between the interior of the hose and the shaft and the space is filled with old packing and rubber.
Any more info?
Happy trails to you.
Captain MARK and his ‘we ain’t orcas’ manatees.

[tkeithlu]

"Captain MARK and his ‘we ain’t orcas’ manatees."

Sad but true. Orcas are honorable marine mammals. Manatees are species Blubberius butti and make cows look hyperactive.

[sailormed]

Try moving the shaft by putting the gearlever in FW and AFT with the engine running. Be prepared for the water inrush.
If your friends are fedup with stuffing boxes you could try to install one of these from Volvo.

[Jack C]

Originally Posted by sailormed

Try moving the shaft by putting the gearlever in FW and AFT with the engine running. Be prepared for the water inrush.
If your friends are fedup with stuffing boxes you could try to install one of these from Volvo.

I love the Volvo seal. Common in Europe but not so much in the USA. My boat in the USA has a stuffing box. Lots of work, water spraying in bilge etc.

The dripless can fail catastrophically.

I replaced a 15 year old Volvo seal, was easy once the coupling was free.

For stuffing box or Volvo the shaft must be smooth. With the Volvo you can adjust the seals position by moving the seal on the shaft tube.

The seal should be burped of air when the boat is put in the water.

[donradcliffe]

Typically 3 rings of packing. Did you get them all out?

[mvweebles]

Depending on how deep into the water the shaft log sits, it's pretty common for only a very modest amount of water to come through the stuffing box - barely a gallon a minute would not be unusual. But to have zero is indeed unusual. Stuffing is pretty stout stuff - hard to believe it was pushed-down unless it was some of the Play-doh style. Depending on the diameter of your shaft, you may be able to slide a thin piece of metal such as a slender putty knife around the shaft.

If your friends over-heated the stuffing box, the shaft may be scored which exacerbates future over-heating. You can field-dress the shaft with a strip of 400-grit wet/dry paper craddled around the shaft while it's running.

Regardless, I'd re-pack with GFO-style synthetic packing and see how it goes. It doesn't take much water to lubricate.

Good luck!

Peter

[Sailorlady323]

Originally Posted by mvweebles

Depending on how deep into the water the shaft log sits, it's pretty common for only a very modest amount of water to come through the stuffing box - barely a gallon a minute would not be unusual. But to have zero is indeed unusual. Stuffing is pretty stout stuff - hard to believe it was pushed-down unless it was some of the Play-doh style. Depending on the diameter of your shaft, you may be able to slide a thin piece of metal such as a slender putty knife around the shaft.

If your friends over-heated the stuffing box, the shaft may be scored which exacerbates future over-heating. You can field-dress the shaft with a strip of 400-grit wet/dry paper craddled around the shaft while it's running.

Regardless, I'd re-pack with GFO-style synthetic packing and see how it goes. It doesn't take much water to lubricate.

Good luck!

Peter

Think you miswrote. Barely a drop a minute not a gallon a minute. You would be sinking

[aqfishing]

I am a commercial fisherman and own a few vessels with shafts ranging from 60mm to 110mm. We have systematically replaced all our stuffing boxes with a Tides Marine Seal.

https://www.tidesmarine.com/shaftsea...l_overview.php

This is a fantastic system super reliable and comes in all sizes.

Does your stuffing box not get an additional water feed from a small seacock? This could be blocked as well.

[Sailorlady323]

Think you miswrote. Barely a drop a minute not a gallon a minute. You would be sinking

[Cheechako]

I think you need to haul that boat and rebuild the entire area.
-The shaft may be corroded or at least rough deposits in there.
-If the boat sits a lot, the water in the gland becomes low oxygen and corrodes a SS shaft. I've seen them look like worms ate trails in them! TWO of my boats over the years had this issue.
-It's not leaking so packing is jammed in there where it shouldn't be.
-You'll need to slide the shaft back enough to see what it looks like.
-You may need to replace the cutlass bearing and or shaft.

[Cadence]

My wasg is someone got over zealous tightening the packing. The packing has been shredded and is in the cutlass flutes or something has grown in them. Maybe running a fine wire through the flutes probably from under water, easier to find, with no packing. For what it is or isn't worth?

[ussvdharma]

Originally Posted by Departing2017

I'm helping friends repack a stuffing box with the boat in the water. From what I can gather, they tried to adjust the packing nut. When they ran the engine in gear, the stuffing box got hot. They saw at least 160F/71C with an IR thermometer before they shut down.

Following the overheating incident they tried to remove the packing nut, and it became stuck (I think what was left of the flax actually folded over on itself and wedged the nut to the shaft), so they asked me for help. I managed to work the nut free of the packing gland assembly and slide it up the shaft so I could clean the old packing material out. The packing was pretty much destroyed, and we had to pick it out of the nut one tiny piece at a time.

So here's the weird part. With the packing nut completely removed from the stuffing box there is no water coming through the shaft log. Am I having a brain fart here? Shouldn't the boat be sinking?

We don't know whether any water was getting to the packing before the incident; I assume not, which explains the overheating. Has anyone else run into this? What would plug up the shaft log so thoroughly that no water could come through? I dove the boat and the shaft orifice looks clean (the cutlass bearing rides in separate a strut). The shaft turns smoothly by hand. I'm at a loss.

I appreciate any shared wisdom here.

Thanks

please NOT ' BRAIN FARTS' THIS IS A FAMILY SITE, USE THE TERM 'CEREBRAL FLATULENCE|" INSTEAD. hAVE YOU CHECKED THE CUTLASS BEARING TO SEE WHAT IS GOING ON BACK THERE...THATS THE ONLY THING LEFT BETWEEN YOU AND THE WATER.