Hot stuffing box, leaky stuffing box. Is there an in-between?

[laika]

I'm not an expert, but seems odd you only see 1L/min with the packing gland off. On my boat there's quite a bit of pressure and the water gushes in. The shaft log sits a couple feet down in the water and creates quite a bit of pressure to force the water up and in when it has the chance.

Just a thought, maybe there's something partially blocking the inflow of water thru the shaft log? Barnacles encrusted over a water inlet hole on the prop aperture?

Hard to see how just drip drip with the gland completely off would supply enough water once the packing is compressed.

[Ryban]

It seems strange to me, too. I expected a lot.more water. There really shouldn't be anything blocking the passage of water. The boat just splashed, and I had the shaft out while it was on the hard. All looked good to me!

There is a plastic-like ring on the male side of the stuffing box, that appears to create a partial seal around the shaft. Perhaps this is reducing thethe flow rate. One thing I can do is undo the hose clamps on the hose connecting it to the stern tube, and see how much water comes out of there.

[907Juice]

Sounds like you may have either the wrong size or type of packing. In my limited experience, I’ve found flax packing to be the best. One other thing that hasn’t been mentioned is, the tightness should be set with the shaft rotating. If you tighten it at rest, it will certainly be too tight.

Loosen the nut then tie that baby hard up on the dock and put it in gear. Crawl below and CAREFULLY move the nut till it is dripping every 10 seconds or so. Put a paper or something under it so you can see the drops better. When you’re done, shut down everything and lock the nut.

Hope this helps
Juice

[jt11791]

Went through the same thing once, drop down to 3/16" packing and you'll be good to go.

[darylat8750]

I wonder if you might be getting each ring tamped in too tight when first putting them in? I always want really good flow when first turning the prop shaft. After running at low rpm for at least 10 min. snug it down until the flow is still a stream but just barely. Run another half hour or so and snug it to the point that it is dripping at least a drip every 5 or 10 seconds. Run it like that at least an hour. Then very slowly get the drip down to one every 10 to 15 seconds while checking temperature . It should never get so warm that you can't leave your hand on it. At this point if the stars are aligned it may stop dripping after you shut down. If I ever get the packing box 190F I would replace the packing.

[Island Time O25]

Do they make packing only in SAE sizes? I noticed that OP's boat is Swedish AND neither 1/4 nor 3/16 fit completely so perhaps 6mm packing would do the trick, if it exists?

[Lepke]

I do packing differently than the group. If I understand your method, you're cutting the packing into single rings that just fit around the shaft. If the packing is cut too long you put too much pressure on the shaft and cut too short it leaks. I repack with a continuous spiral of packing with the ends cut sharp so the total packing is equally thick all the way around. The shaft has to be lubed or you stand a good chance of ruining the packing. I use waterproof grease. If I can't reach into the shaft housing to grease, I grease the inside of the packing as it's placed. New packing should last many years, hundreds of hours. Rarely have I ever had to repack my private boat more than once during ownership.

[stnick]

I only use the new GORTEX packing . Its a no drip packing !
I pay special attention to the shaft smoothness. A fine emery paper strip back and forth to polish that shaft. I have a set of dental picks to remove any packing caught up inside that i just cant see. Use the lube ! No sence paying for no drip and having it drip !!
I like it , Have a dry space under the shaft !!!

[Ryban]

So I slept on it to avoid making any rash decisions and tackled it again this morning, and I have good news to report -- the problem is resolved! (for now)

After reading the helpful posts here, and talking to a few people around the boatyard, I decided to remove the 1/4" packing (for the second time), and switch the 3/16". To make the 3/16" fit better, I did gently flatten it with a hammer before cutting the rings to size.

After one ring, the shaft seal leaked quite a bit. After two rings, it leaked a lot less. After three rings, I was able to fine-tune the dripping, and the packing nut only gets warm.

I will leave it like this for the time being, but I suspect I have room for 1 or 2 more rings in there.

[georgeg305]

Re: shaft packing leakage.

I use three rings.
First of all, I cut the length by using the stern rail which is also 1" diameter. I cut the ring on the diagonal. Space the rings so the cut is in a different place.
There is a new stuff on the market that is better than flax. Dont remember what it is called.

[a64pilot]

I have the Gore Tex packing myself, I have mine adjusted so that it never drips, when running it will keep a water ring if you will right where it normally drips, but no drip, and the shaft is barely warm, maybe 100 F in 85 F water.
If it stays this way, I don’t see the need for a dripless seal.
Maybe mine is an anomaly and will start leaking soon, but it’s been a year and a half with over a thousand miles of motoring on it.

[CarlF]

Has anyone using Gore packing seen it cause corrosion on an Aquamet or Aqualoy shaft?

MainSail scared me with his pictures of what the graphite in Gore packing can do to a bronze shaft in just a year. I guess this applies to any of the new packings with lots of graphite in them. He says he checks his Aqualoy shaft once a year for corrosion at the packing nut.

Also, has anyone running with Gore packing with "no drip" had problems with crevice corrosion on a stainless alloy shaft from the lack of oxygen?

I'd love to tighten my Gore packing to have no drip but not if it might corrode my shaft.

[sbmar]

This how we do it.. 25 yrs ++, 100's on high annual hour commercial & recreational vessels, Pure teflon, run them in at up to 1800 RPM, a grease fitting that injects grease someplace near the middle of the packing material, zero leak at the dock, close to dripless when running-------very long term and 100% reliable..



https://www.sbmar.com/articles/packing-a-packing-gland/

https://www.sbmar.com/articles/packi...winning-combo/

https://www.sbmar.com/articles/every...haft-packings/

https://www.sbmar.com/articles/best-...haft-packings/


Tony

[Bluejacket]

Hanging upside down over the engine has never been much fun.
I've looked at several of the the replies and at the risk of repeating what has already been said:
Tearing the old packing out is the first hurdle. Did it all come out or did a piece tear off inside ?
Cutting a little to short is not as bad as cutting to long.
Lastly, the joints need to be staggered. If you're putting in 3 rings each joint should be 1/3 the way around the shaft from the last joint.

[Twister]

Originally Posted by Ryban

....wonder if I did indeed use the right packing material size.

I used 1/4", it seemed to be the same size as of what was in there, and though it was a bit of a tight fit, I suspected it was supposed to be. The next size down is 3/16", which I can attempt to use.
.

An easy way to find what size you need is to try and insert a 3/16" or 1/4" drill bit into the gap. Whichever best fits is the right size.


I use PTFE packing in my sterngland. It doesn't drip or get hot and the the propeller will freewheel when sailing.