Packing Gland Adjustment

I've just had my port engine removed, rebuilt, reinstalled. That's a story unto itself. My question is, what is the proper drip rate for the packing gland, and how do I adjust it if it's not dripping enough?

Thanks in advance

Many of the packings today you can get to be dry st rest and just barely oozing moisture at cruise rpm and it will stay cool enough.

The rles of thumb from 50 years ago are long dead but some still abidr by them. The only rule is that the packing gland and shaft stays cool to warm.

The only reason to have drips at all in some peoples mind us to keep oxygenated water in tbe packing to prevent crevice corrosion.

Ok, thx........I think.........so you're saying if it's dripping at all, it's probably ok? Or feel the shaft while underway?

Its OK if running warm to cool, the drips are meaningless...but with just plain old teflon packing I still get an ooze that I can see and feel... but no visible drips for manny, many minutes or wet spots in the bilge....but after msny hours I may get a tiny pile of "ooze" right under the packing.

wyoboater said:

Ok, thx........I think.........so you're saying if it's dripping at all, it's probably ok? Or feel the shaft while underway?

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Just be certain the shaft is not moving when you get around it. Much potential for very nasty injuries if moving. Best bet, use a non contact thermo. Harbor freight has them for around $25. Much less than an ER visit

John

Adjusted our a few days back as it had been leaking more than I'd like underway but stopped when not spinning.

Stuffing box temp is 20c at start and after an hour gets to about 35c.
I'm guessing that not defined as hot?

Our point of reference is 17f above ambient. After two hours we run +2f, after 40 hours we level off to +17f. We run a 2.88 reduction gear and we usually run around 1800 engine rpm. Our shafts are 2” diameter. No drip at rest, 3-6 / min underway.

If you have 3-6 drops per minute while running and temps are stable, you're good. If temps keep rising you risk overheating the packing that scores the shaft or destroys the packing.
Lets say you are dripping 60 drops/minute. Adjust the packing to cut drips in half then run it in an hour. Cut the drips in half again and run in another hour. Don't try to shortcut. Once you overshoot, the temp will scream up, the packing expands, the drips will cut off, and the packing gets smoked.

"what is the proper drip rate for the packing gland, and how do I adjust it if it's not dripping enough?"


ZERO ,,underway or stopped, with modern packing .


GFO or similar .

http://www.duramaxmarine.com/shaft-ultrax.htm

This stuff works great. No drips. Start off very loose packing nut as Archie states above.

Leaking can be an Indicator of poor alignment. Think of a drill bit not fully centered in a chuck, it defines a more oval movement that expands the packing around the shaft and lets it drip. No amount of tightening will solve an alignment issue without overheating the packing. Though fresh packing is more forgiving, that’s not really a fix to alignment issues, if you have them.

Also, if you tighten packing that has already baked out it’s lubricant and baked the fibers into a hardened state, you can easily score a shaft.

Which is to say that I don’t like tightening packing that is not in a known state of good condition, especially when it’s so easy to change. Only takes a short time to do it and costs little and can be done easily in the water.

If you have dripping beyond normal with fresh packing and a gland that is running too hot, look into your alignment, cutless bearings, prop balance and shaft straightness.

A 'rule of thumb" that I read is the packing should be no more than 30 deg F higher than the ambient water temp.
Again, it's a guideline, not an absolute.

Easting said:

Duramax Shaft Sealing Systems: Ultra-X High-Performance Packing

This stuff works great. No drips. Start off very loose packing nut as Archie states above.

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I know this has been mentioned in a few previous threads, but did we ever come to a consensus as to whether or not issues due to dissimilar metals is a problem with this type of packing?

My packings drip once a minute while underway and only ooze while at rest. The water temp is 50 degrees and my stuffing box is at 80 degrees while under way. I use an infaread gun to monitor temps. I bought the gun at Lowe’s Hardware for $20.

My last boat never dripped and it’s temp was always water temp.

Harry said:

I know this has been mentioned in a few previous threads, but did we ever come to a consensus as to whether or not issues due to dissimilar metals is a problem with this type of packing?

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I don’t think it normally causes any corrosion issues, but I suspect it could if it were to soak for extended periods in salt water without exercising.
I’ve seen shafts damaged with traditional flax packing from sitting idle.
Another good reason to do a freshwater flush after every trip!

During my days as a millwright it was pretty much gospel to have three rings of packing (minimum) and a regular drip rate on packing glands. Imagine my consternation as I attempted to apply this principle to the packing gland on our single screw trawler. I tried everything I could to get the balance of drip rate and gland temp I felt was correct, constantly fretting over the thing, setting and re-setting until finally I gave up.

The gland has only two rings of PTFE packing and barely drips at all. There is no discernible 'drip rate' other than the little catch tub slowly collects water and if I feel the bottom of the gland in operation my fingers come away wet. Nonetheless it stays cool. It had a higher temperature with three rings but a constant drip.

It's not text book but it's also not wrong. It's lubricating enough to stay cool while keeping the shaft sealed and that's it's purpose. As my wife likes to tell me 'it doesn't have to be perfect all the time, it just has to work'.