Advice on Packing Glands

[stephen Penny]

My 1987 sailboat has a plastic packing gland. I would like your input on how you adjust it to ensure adequate leakage for normal motor operation and when the engine is off. As the boat is still new to me I am not sure the auto-bilge works and if the information I obtained below on-line is correct I am concerned about overflowing onto the cabin floors when I am away during the week. Would that happen? I plan to check the auto-bilge operability this weekend. I have packing gland wrenches to make the appropriate adjustments.

"The packing gland is located under the aft berth cushion. A properly adjusted shaft packing gland should drip slightly (from 1 to 2 drops per minute) with the engine off. Too loose an adjustment will allow too much water in the bilge and engine operation will spray water from the shaft. Too tight an adjustment will fob the engine of power, and the lack of water lubrication in the packing gland can generate enough heat to damage the gland and/or score the propeller shaft.


ADJUSTMENT:

1. Hold the packing nut with one wrench, use a second wrench to loosen the lock nut. Turn the lock nut far enough to keep it from interfering with the next adjustment (2 or 3 turns.).
2. Tighten the packing nut to obtain 4 to 15 drops per minute. Hand tightening of the packing nut is often sufficient to obtain this adjustment. If this is not the case, an additional 1/4 to 1/2 turn with the wrench should produce the desired results.
3. Hold the packing nut in place with one wrench, and use the second wrench to bring the locking nut securely against the packing nut. Make certain that the locking nut is tight. Failure to do this could allow the packing nut to back off when the engine is operating.
4. Operate the engine at slow speeds in forward and reverse and use a light to check for excessive water at the packing nut. Shut off the engine and recheck packing for proper drip."

 

[Ed Schenck]

Your included instructions are accurate. But you really need to have that bilge pump working correctly. And not just for packing gland drips. Other small leaks could accumulate. Or do a poll and see how many of us have rushed off, late for dinner, and left the hatch open.

 

[Steve Dion]

I have never heard that there should be ANY drip when the shaft is NOT turning.

I believe that the standard is NO leak when the shaft is not moving and 3-5 drips per minute when running the engine.

If you go to one of the newer packing materials or dripless systems you can have a dry bilge all of the time.

As far as testing you bilge pump, just put the hose in the bilge and see what happens. It should kick one once the float switch detects water high enough to activate the float switch. It should also kick on when you activate it manually from the panel.

If you have any doubts, I suggest that you have a mechanic repack your stuffing box and show you how to adjust it. Paying for some of these services once and learning from the pro is often a worth while investment in education.

 

[stephen Penny]

Thanks all for the information. The boat is still new to me and the surveyor did not highlight whether these systems where functioning properly while in the water and I have not yet found an auto bilge switch. I checked the sailboat bilge mid-week and it was dry as it has been since I purchased the boat last November. Manual bilge works like a champ and the bilge level is below the float switch so I suspect it works fine. This afternoon I plan to simulate the auto float switch operation and wiring and adjust the packing glad, as required. Does anyone routinely check the packing gland setting for proper drip? If so, on what frequency?

 

[jtm]

I'd make sure that your engine to shaft alignment is proper before getting too exercised on the packing gland.

In regards to your bilge pump- its easy enough to check- Put about 2 inches of water in the bilge until the scissor switch engages the pump. Secondly I'd test the manually operation by flipping the bilge switch on the panel. Ensure the water is making it out of the boat and not re-circulating somewhere and eventually back to bilge. Who knows what shape the connections/hoses are in.

Very importantly, check for the proper size fuse is in the bilge circuit!. I recall my initial pump cooked, cracked the housing and fried years ago because someone in commissioning didn't put the correct capacity fuse in the panel socket. BTW, they had also plumbed the seawater strainer backwards too-) .

Since you don't know how good the bilge pump is- and its your primary defense device- I'd buy a new one! Its the cheapest insurance for your boat. Make sure you have the proper hose diameters from the bilge device spigot to the thru-hull exhaust. You don't want blowback from improperly matched and/or loose adapters.

While most people get Rule units, I'd consider getting an all-in-one bilge/switch assembly- they are neat, compact taking up less space in the bilge- and less chance of a scissor getting stuck in an engaged position or with some sub-floor debris that might find its way there on a steep tack. In this regard I've found the ATTWOOD Sahara model(various capacity 500-750gpm-check hose diam.) excellent - its like a short conning tower with "integrated float switch" with on-tower manual switch(in addition to what you have at the panel).Check it out online.

Lastly- I'd wire into the bilge pump circuit an "alarm" (buzzer mounted under companionway step) - nothing extravagant - just something to let you know when and how often you are pumping water. Without it you usually can't hear it bilging when you are sailing or motoring. If its going on too often - then you will know you gotta go down and check things out- like your intake hose and/or your packing drip. Go to Radio Shack - get one of those piezzo(spelling?) buzzer or beepers and put it into the bilge circuit. I had also wired my Racor's bowl water level sensor into the same alarm. Years ago I read somewhere that a sailor had some work done in a SW Asian port, and a few days out in pacific he had the bilge alarm go off. Turned out his shaft wasn't properly fastened and had slid out- he used one of those wood cones to plug the shaft opening. Go figure.

 

[Rick D]

Mixed Advice

I'm smiling since I went through that myself 20 years ago. Altho I had a couple of inboard boats before my 1990 Hunter, I had not had one with the plastic stuffing box. I was worried that it didn't leak when not running and just slightly (a couple of drops a minute) when running. That was less than the ones on my prior boats, but neither of them at rest would leak as much as your surveyor recommends. I, like Steve, have understood it should not leak unless the shaft is turning. But, back then it made me uneasy how little it dripped. To make a long story shorter, I backed it way off but it still sisn't leak and it was too loose. I snugged it back up. A few years later, I tried a dripless packing. It would not work in the nylon gland, so I replaced it with a bronze one. I never could get it to quit leaking more than the original. I put a PSS dripless box on it and have had them ever since. Bottom line, I would not worry about it now but would eventually consider repacking it with Teflon packing or change it over to a PSS unit next haul out.

 

[Steve Dion]

Stephen:

The automatic bilge pump is the same as the one that you trigger with the switch. Your pump should either have a float switch (external) or it is built into the pump.

 

[Steve Dion]

Stephen:

What marina is your boat located in?

 

[Bill Roosa]

Some dripage data for ya

I had a float switch go bad this Fall. As close as I can figure it went about two months before I noticed it. The only real drip was the prop shaft gland which was dripping at about once a minute. The bilge on my 40.5 legend was only about 1/2 full. Sure did make here stiff though. I'd say there was 30 gal in the bilge max as it took about 45 seconds to empty with the bilge pump on manual over ride.

 

[stephen Penny]

Steve,

My sailboat is currently berthed in the Richmond Marina Bay. Next month it will in Brickyard Cove, Point Richmond.

 

[Warren Milberg]

I'd like to suggest that you replace the white nylon OEM Hunter gland with a bronze gland. This is not a hard job and most DIYers can do it themselves. Cost is less than $100 plus your own labor. I never had a problem with my OEM gland, but I never trusted it either. Not sure about your boat, but mine had three separation/compression washers between the two rings of packing material. (See pic below) With very little space between the coupler and gland, it was impossible for me to remove the old packing material and washers when it came time to repack the gland. I changed it to bronze gland and have been very happy with the result. BTW, I also agree that a gland should not drip at all when the shaft is not turning. With Gore packing material, it is possible to adjust the packing nut to hardly drip at all while maintaining a coolish gland when the engine runs.

I always check the drip rate on my packing gland (and the integrity of the hose connector) prior to and after sailing. No big deal as I close the nearby raw water intake seacock and put the ignition key on its handle at that time.

 

[stephen Penny]

Great information. Thanks all!! I purchased properly sized packing gland wrenches and adjusted the gland so it does not leak with engine is off (which I discovered it did last weekend) while having a small 1 drop/minute while operating. Auto bilge was not working so I replaced the bilge float switch. Next I need to hard wire it to the battery for auto operation. Then on to my next project - new running rigging.

 

[stephen Penny]

jjmcue,

How do check whether the engine to shaft alignment is proper and is this done in or out of the water? The boat currently runs great.

 

[jtm]

My thoughts are If you figure that you are adequately tight at the packing and you constantly find you have to adjust- you may need to check further.

First -do you have growth-barnacles or eelgrass etc on you prop or shaft, that would also cause the shaft to extraordinary load/stress and/or movement in operation. What condition are the motor mounts ?are they shot ? are they doing the damping job?

I would look at the engine and see how much it vacillates at a notch or two above idle and and at a midrange speed - under load( in gear tied at marina slip). Also watch the packing connection and try notice if it appears to be bending/stressing (easier at lower rpm.) Is there some wear band on the shaft as it exits the packing cup? Shaft play should show up as well in this area.

If you still feel something is overly twisting/bending- then you gotta dig out the gap feelers and measure the even mating of the shaft flange and the tranny output flange- and see that it is evenly gapped at 12,6, 3,9 o'clock as they come together. A fuller alignment would have you ensure the shaft is located dead center 12,6,3,9 coming out the tube(block it to the exact position before doing the flange measurement) and then properly mating the tranny output shaftflange. Check the manual on the approach -there may be some online "how-tos"s. BTW,

This alignment process could be a topic in itself. maybe others have add-on tips.

 

[stephen Penny]

jtmccue,

Thanks for your input. I will save this tread for future reference as there is lots of good information. I did check the shaft and packing gland while motoring this weekend. All was fine. But as a new first time older sail boat owner I am trying to be cautious. It is not like my Correct Craft ski boat, albeit 15 years old and operates like new and is garaged vs. my 23 year old sail boat which is in a tough marine environment 24 / 7 which is great shape after a lot of sweat equity.

 

[Steve Dion]

Stephen:

Brickyard Cove is a nice spot. If we are heading down to the bay maybe we can get get together. I owned a '85 H'31 prior to my '94 Hunter Vision.

One thing on your packing glad. Be sure to check it when it has been running (shaft spinning) for a while. The shaft should NOT get hat. If it does, you may want to loosen the nut to allow for a little more drip.

 

[stephen Penny]

Steve,


If you sail this way please let me know as I am here most weekends and would like to meet you. Otherwise I am in the delta water skiing out of Brandon Island (Lighthouse on the delta loop) during the summer/fall (always welcome skiers and have all the equipment). This weekend I purchased new packing gland nut wrenches, adjusted the gland and checked its leakage rate for satisfactory operation under power. Today I replaced the auto bilge float switch and fuse before work and the automatic bilge finally works. Surveyor did not identify this last October. Next sailboat purchase I will know more of what to look for. Last maintenance/upgrades items are to install new kerosene tank for the Force 10 cabin heater (install and test this weekend) and new running rigging by a rigger in Brickyard in April.

 

[Steve Dion]

Stephen:

You can save yourself a LOT of money by purchasing your line through this website.

This weekend looks washed out (rain through Sunday) so I doubt that we will make the trip over this hill. We will probably be down the following weekend.

If you contact me through the email, we can see when we can get together. Our marina is about 8 miles from Brandon Island.

http://hiddenharbormarina.com/