Packing nut adjustment

sailingdog · Jan 20, 2009

Sounds like you should be looking to repack it now...

Get the GFO goretex reduced drip packing material. Mind you, this stuff will drip less, but when the boat is in gear, it should still drip. If it isn't dripping when the boat is in gear, you've over-tightened it and will likely burn it out and score the propshaft in the process. If you don't want it to drip at all, you need to install something like a PSS.

Jim · Jan 20, 2009

I agree too. Repack with the good stuff every 2 to 3 years. Better to let it drip then get hot.

Deadline · Jan 20, 2009

I disagree. From what John has said, he's fine. The shaft doesn't have to drip, and it won't necessarily score the shaft. To verify, put your hand near the nut when under power and see if it remains cool. If hot, then yes it's too tight.

In any case, don't try to replace the stuffing while still in the water. Do it on the hards.

For scads of research and anecdotes, go under Forums on this site and to Research wehre the Archives are.

Or you can follow this simple checklist.

Stuffing box on the hards, not in the water

REMOVAL
Unscrew thin brass jam nut to free up big one
Unscrew big brass nut completely.
Spray WD-0 inside to loosen up flax.
Turn corkscrew pick into first layer, pull Vise Grip offers better leverage
Repeat until all layers removed two if was chinzy, three more likely, four if anal
Clear out brass seating of any loose debris so new flax sits well

INSTALL
Buy 13 inches Teflon 1/4 inch = three at inches
Turn first wrap tight, mark with thumbnail or do at home with 1-inch stanchion
Cut with share razor knife or Dremel saw
Cut remaining 2 wraps to same size
Poke first one in clockwise by turning big nut slowly
Mark where it started with red pen
Screw down onto shaft to pack, by hand only
Loosen and repeat two more times
Do not overtighten, or will burn flax and not seat properly

TEST
When launch, be prepared to tighten using wrench keep jam nut loose
Should be no drips at rest, do not overtighten
In gear, should be no more than 1-3 drops per minute
Tighten one flat at a time while in gear
If the big nut is warm, back off as too tight burning the flax,unlikely at this point
Always retighten the jam cleat to avoid inadvertent loosening
When it’s right, try a day or week later takes time, be patient
Check again for three weeks then three months later
Should last three or four years okay to tighten one flat a time, over time

Roger Long · Jan 20, 2009

sailingdog said:
Get the GFO goretex reduced drip packing material. Mind you, this stuff will drip less, but when the boat is in gear, it should still drip. If it isn't dripping when the boat is in gear, you've over-tightened it and will likely burn it out and score the propshaft in the process.

I agree on the GFO. I'm not sure it needs to drip though. I tried as hard as I could to score a stainless steel bolt by chucking it in an electric drill clamped in a vice with GTO around it. I squeezed and ran it until the GFO started melting and smoking and the bolt just took a light polish. It's great stuff.

The gland does have to be tightened about once a month on my boat which is used nearly daily. It's hard to see or get at so it usually drip for a while before I get around to climbing in and tightening it.

Lyle · Jan 20, 2009

I have used the GFO packing for several years on 2 different boats, a Hunter 35.5 and a Kristen 465. It is great stuff and does not have to drip to provide proper shaft lubrication. It does need to be adjusted periodically in order to keep it virtually dripless.

Maine Sail · Jan 20, 2009

John said:
I found, yesterday, that there was a steady drip from my packing gland - about one drip every 5-8 seconds. When I tried tightening the nut, even if I tightened it the slightest amount, then there was no drip whatsoever. In other words, I can only get no drip at all or one that is so steady that a lot of water collects. I tried adjusting both with the shaft turning and when it was not.

Is this a sign that I need to replace the packing? (The engine is 10 years old, but only has a little over 400 hours on it.)

John,

The packing has likely lost its life and has become rather hard. Ten years is a long time for traditional flax despite low hours. Your packing may come back after running it in gear for a while but it should always drip when in gear. Traditional flax packing is lubricated by water, no water, no lubrication. At rest you can often get them drip free but this is very dependent upon the original installation, break in and the condition of the shaft, but drip free at rest is not a guarantee.

You can replace your packing in the water, it's done all the time, and it's not that difficult, but do plan ahead and be prepared. For a first time I'd say try it on the hard but if absolutely you can't just think it through.

I would only replace this with Gore GFO or Western Pacific Trading GTU but pay attention to the break in instructions and do not over tighten. This stuff can take many hours of run time to fully break in. Once broken in it can drip very, very little when running and will most likely be bone dry at rest..

For more clarification on GFO:
In the Gore GFO marine instruction they just say to adjust it to the desired leakage. It still needs a little water to lubricate and this is usually less than a traditional based flax whether it be Teflon impregnated or paraffin based .

If you're going to stay with a traditional flax based system the GORE GFO is by far the best flax you can buy. The white Teflon impregnated flax is NOT GFO. It is regular flax with PTFE instead of a paraffin based lubricant only. GFO is blackish gray in color!

Gore GFO Marine Instructions:

Gore GFO Instructions said:

AFTER THE LAST RING IS INSTALLED, take up bolts finger tight. Do not jam the packing into place by excessive gland loading. Make sure gland bolts are taken up evenly. STOPPING LEAKAGE ENTIRELY AT THIS POINT WILL CAUSE THE PACKING TO BURN UP.

Click to expand

Gore GFO Instructions said:
After about one or two hours of running time,, check the stuffing box for leakage, and make a final adjustment to attain minimum leakage.

Please note that it says MINIMUM LEAKAGE.

The marine instructions are very careful to NOT mention that it can be run with no drips but can be very MISLEADING.

Marketing:

Gore GFO Marketing said:

Bilges stay dry

Click to expand

Gore GFO Marketing said:
Since GFO fiber dripless packing is four times more thermally conductive than flax, it needs virtually no sea water for lubrication or cooling. And, because it doesn't swell or shrink, leakage is controlled and kept to an absolute minimum. In fact, you'll notice that your bilge is dry and cleaner, because this remarkable packing hardly ever drips. It's so conformable and flexible that it will solve most perpetual problem leakers, too.

They use words like "virtually" and terms like "leakage is controlled and kept to an absolute minimum" and "this remarkable packing hardly ever drips" while at the SAME time saying things like this: "bilges stay dry"???

It's no wonder people are confused their literature contradicts its self in the same paragraph!! It should say "bilges stay drier" not "dry". The bottom line is that GFO still needs some water for lubrication, as stated in their installation instruction, but much less than other packing materials..

It is NOT drip free! It just drips considerably less.... In most instances it can be made drip free, even on a scored shaft, while at rest but when running it should stay cool and have some drip.

Many have reported no drips with GFO while still running cool. If you can achieve this through a proper break in it is wonderful but I would not go into it with that as your main plan..

Maine Sail · Jan 20, 2009

John said:
1) Are there any drawbacks to the dripless packing aside from cost?

2)My plan is to do it in the water but get a diver to put some wax around the exit of the shaft and then tie some plastic around all of that. I figure this will lead to very little water entering while I fumble and bumble around for my first time changing this. What do people think of this?

It depends which "dripless" packing. If you're using Gore GFO or WPT GTU it is a no brainer. The stuff is not that expensive. I would not use the green clay like goop or the white teflon impregnated traditional flax. Gore has no added junk and the actual fibers are the lubrication when mixed with water. Traditional flax is impregnated with either paraffin or teflon but the fibers it is woven from are still abrasive unlike GFO or GTU.

You don't need a diver. A bicycle inner tube cut open and wrapped around the shaft log & secured with zip ties is more than adequate as is a wax johnny ring. Both of these can be applied after you remove the flax nut to stem water ingress.

Here is a photo based how to article that shows & explains the steps.

Re-Packing A Traditional Stuffing Box (LINK)

Warren Milberg · Jan 20, 2009

Couple of observations re packing glands. First, on a couple of boats I have been able to adjust a conventional gland with conventional flax packing to not drip at all when the shaft is not turning, and to "hardly drip at all" when the engine is in gear. You can tell if your adjustment is too tight (too loose = too much leaking) just by running your engine in gear in your slip (tighten up the dock lines) for a half hour or so. CAREFULLY put your hand on the rubber hose and packing nut to feel how cold, warm, or hot it may get. If you can touch a conventional bronze gland easily, it is not too hot and your adjustment is probably about right.

If you need to replace the packing material, I also recommend doing it on the hard the first time. If you do decide to repack it in the water, think about every possible thing that could go wrong, and how you would deal with it, before hand. Nothing ever goes quite as planned in boat repairs. Once the gland is successfully repacked and the compression and locking nuts adjusted, remember that you'll need to test and readjust the nut a few times more as the new packing material wears in.

Chuckbear · Jan 20, 2009

John, A drip very 5 to 8 seconds is not excessive. The general rule of thumb is every ten seconds. Your adjustment to no drips could mean only you have it too tight, If you are getting a drip every 5 to 8 seconds you are close to adjusted and tightening more than 1/16 of an inch is the max you might want to apply. Look at the amount of adjustment you have left on the packing nut. If it is almost as tight as it can be you need to repack, but if you have enough threads to adjust even 3/4 of an inch or more you are probably fine till your next haul out. I have redone packing hundreds of times.

Chuckbear · Jan 20, 2009

John, That is what a bilge pump is for. Packing glands drip. If you don't want the drip you need to install a true dripless system. If you repack it, it still must drip.

Franklin · Jan 20, 2009

Chuckbear said:
John, That is what a bilge pump is for. Packing glands drip. If you don't want the drip you need to install a true dripless system. If you repack it, it still must drip.

I might have missed it but I haven't seen anywhere where it's stated that we are talking about while the motor is in gear. If the prop isn't moving, it shouldn't be dripping at all. I don't care how much it drips while I'm motoring because I have constant juice to the pump to keep the bildge at it's normal level. It's when I'm not motoring is when I care about drip. So if it's not dripping while tied off in the slip with the motor off, then it's just fine. If it is dripping, tighten until it stops but do it very slowly to prevent over tightening.

HOWEVER, considering many boats have sunk because of a failed gland, replace it the next time you pull her out of the water. Especially since you don't know how old it is. I recommend every time a used boat is bought for the new owner to replace the gland.