packing seal drip?

Discussion in 'Inboards' started by freddyj, Aug 9, 2016.

  1. freddyj
    Joined: Oct 2013
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    freddyj Senior Member

    I'd like to run an inboard motor, gas or electric, on my small sailboat. But, everything I've read, it seems the packing seals always drip. Is this true? if I leave the boat for a long period of time, I don't want to come back to water in the bilge. Any info appreciated.
     
  2. jehardiman
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    jehardiman Senior Member

    Depends on the seal type.

    The classic gland seal packing is required to drip in operation to lubricate the shaft. When non-operational, the gland nut is tightened on the packing and the drip stops. But you have to remember to loosen the gland nut next time, or you will heat score the shaft. Because of this necessary tending, classic gland seals have gotten a bad rap. Either they are never tightened and therefore always leak, or the are left tightened and damage the shaft.

    To combat this problem, 'dripless' seals were developed. In a dripless seal, a face seal contains the water the gets through the stern tube and bearing. When spinning there is some minimal leak-by, but when stopped surface tension prevents leaks. Dripless seals do require some adjustment when originally fitted and do wear/corrode, so it is still not a perfect system.
     
  3. freddyj
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    freddyj Senior Member

    I remember years ago, being on a fishing boat in Croatia. It had a 5hp inboard engine like a briggs and stratton. The shaft had bearings top and bottom and a grease zerk on the tube. Seems they filled the tube with pressurized grease to keep from water entry. Granted this was a low rpm setup with a big prop. Does this sound feasible on a sailboat?
     
  4. jehardiman
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    jehardiman Senior Member

  5. waikikin
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    waikikin Senior Member

    I skimmed through the report, seemed to represent as a non issue as when operating correctly no discharge, seems every outboard has an oil filled gearbox just a seal away from leaking, maybe I missed something. Plenty of small vessels introduce grease, some even fill the whole stern tube with it so some must make its way out on periodic replenishment, a mates is set up for a pump every 4-8 hours so that is some form of pollution, maybe way less than an old two stroke. The thing to do is use whale grease;)

    Jeff
     
  6. FAST FRED
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    Location: Conn in summers , Ortona FL in winter , with big d

    FAST FRED Senior Member

    Use a modern (expensive) packing like Duramax.

    It will seal , no dripping required underway.

    Plan B is to find a screw down grease cup (old farm machinery) and hook it to the stuffing box with copper tubing lead to a simple access location..

    On leaving the boat a turn or two will stop any drip .
     
  7. missinginaction
    Joined: Aug 2007
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    missinginaction Senior Member

    A couple of options would work here. A little drip from a traditional packing gland (stuffing box) can easily be dealt with. If you're worried about water intrusion while you're away from the boat, consider installing an automatic bilge pump. You wire this (with an inline fuse, or on a 24 hour circuit) so that the pump has power at all times. I use a couple of these and they've proven reliable. There are others.

    http://www.ceshowroom.com/ProductDe...8966&click=2&gclid=CMOSotnwts4CFQGOaQodOlkEiA

    Another alternative is the PSS or Packless Shaft Seal which is mentioned above. I have very limited access to the shaft log on my boat (a v-drive) and decided to go with the PSS. I've not been disappointed. If you look at these seals on a website, they look a little intimidating (at least they did for me). Once you actually have one in your hand and can see the parts you'll find the set up is pretty straight forward.
    Correctly set up (and it's not rocket science) PSS seals DO NOT LEAK. They don't leak at the dock and they don't leak when in use. I've had one in my boat for three years now. The only water I get in my bilge comes from a couple of little leaks in the back cockpit. When the weather is dry so are my bilges. I mean dry, as in bone dry, as in nothing, zip, no water. Clear?

    Good Luck and Regards,

    MIA
     
  8. gonzo
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    gonzo Senior Member

  9. 7228sedan
    Joined: Nov 2009
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    7228sedan Senior Member

    I second Gonzo's response here. I use the Western Pacific Trading Teflon packing. There's a bit of a drip when it's brand new, however as it heats up and break sin, the Teflon is spread out along the shaft. It forms a drip less seal when underway and at rest.
     
  10. tom kane
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    tom kane Senior Member

    http://www.chesterton.com/en-us

    In the Dairy Industries we had hundreds of pumps running 24/7 and it was rare to see any leaking glands pumping all sorts of liquids. Check out above web address.
    Many types were used including ceramic and many other flexible stainless steel glands doing much harder work than what happens in a boat.
     

  11. sdowney717
    Joined: Nov 2010
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    sdowney717 Senior Member

    I have used GFO marine packing for the last 10 years, no drips.
     
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