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Rudder Post Leak

Discussion in 'Ocean Yacht' started by alvareza, Aug 2, 2019.

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  1. alvareza

    alvareza Member

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    My 46 Ocean Yacht ‘07 has both rudder posts leaking when underway. The leak is coming from the joint between the rudder post and the hull, not from below the packing nut. Attached is a picture of the rudder post from the inside and the rudder outside. ​

    What’s the best way to remount the posts? Is a backing plate needed inside? Is 5200 enough or is some fiberglass/epoxy needed to fill the gap between the rudder post and the hull?

    Appreciate any advice.
    upload_2019-8-2_17-4-16.jpeg
    upload_2019-8-2_17-4-45.jpeg
  2. cleanslate

    cleanslate Senior Member

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    You got to remove the four old post nuts and bolts , and replace them with new ones the same that came out.
    clean things up between the rudder post square block and the hull the best you can and re bed with 5200 .

    You may have to use good old bedding seam compound .
    That will work no matter what.
  3. Capt J

    Capt J Senior Member

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    A backing plate would also be a good idea if you could get it to seat correctly in addition to what clean slate said.
  4. Capt Ralph

    Capt Ralph Senior Member

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    Looks like the nut top is wet. You sure the gland not leaking?
    Our Bert used to leak when underway, stopped when static. Worn log tubes.
    Even US Yacht shafts logs did not leak on the hull.
  5. Capt Ralph

    Capt Ralph Senior Member

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    Wow, That's a lot of pitch on those wheels.
    Warp speed??
  6. alvareza

    alvareza Member

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    Good advice from all. Thanks. The inside finish seems fairly uneven to get the backing plate to seat evenly. Going to give it a try, seems like a good thing.

    Gland might be leaking too. There is a good amount of water, think a spray or spurt , from the gap underway. Especially when the autopilot makes a course correction. I will re-pack the gland when I reseat the rudder posts.

    28x36. Cruise between 16-27 kts. WOT at 32kts. 16kts going to canyons with 6 people, gear and ice at 40 gph. Coming back with less ice and fuel, same people 24kts.

    Original magazine test was 28x38 and a WOT of 35 kts.
  7. Capt Ralph

    Capt Ralph Senior Member

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    Thru the many years of working on old boats, I have learned the hard way; rudder post are the most miss - understood.
    The rudder shafts do not spin like a propeller shaft yet we expect the glands to work the same way.
    They do not...
    We keep tightening them down and are amazed two weeks later it is wet down there.

    It takes more than a bi monthly visit to look and ***** about leaking rudder post gland.
    It takes effort and often visits and adjustments to get them to stop leaking and vigilance to stay on top of a dry bilge.

    The un-even mounting you see between the hull and the mount of the rudder shaft tube means nothing towards your leak. AS LONG as it has never changed. Where are your purchase photos. I bet they are intact.
    My 41 year old Bert was suspected of leaking rudder post assembly at the hull after purchase 16 years ago. NOT...

    Oh, Not to feel special, I noticed my aft pump running on last weeks run. With a smile to my self, been busy, I know I have messed up and over due on my old 41 year old rudder post, that are usually dry.

    We own Aqua Space Ships... Maintenance is never easy, on schedule or completed.
  8. Capt Ralph

    Capt Ralph Senior Member

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    I luv your prop specs and updated pitch.
    Don't let the repair shops take away any diameter.

    Rare to see, prop nuts on correctly also.
    Last edited: Aug 2, 2019
  9. Capt Ralph

    Capt Ralph Senior Member

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    Your pictures do not show a top pillow bearing. I'm assuming the weight of the rudder is on those cold pins and nylon washers. The rudder shaft tube taking the side force from the tillers.
    Could you send some above down pics of the rudder shaft to confirm my thoughts?
  10. Capt J

    Capt J Senior Member

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    I would take the entire posts off, clean everything thoroughly, rebuild or replace them, before putting them back.
  11. Beau

    Beau Senior Member

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    Coming back aren't you suppose to have a thousand pounds of fish in the wells to slow you down? Just teasing....
  12. alvareza

    alvareza Member

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    It would have to be an epic fishing trip to come close to replacing the fuel load. It could be done

    I am leaning towards a full clean and reinstall. I want to understand the current issue to make sure I get it done right.
    upload_2019-8-5_7-46-13.jpeg
  13. rtrafford

    rtrafford Senior Member

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    If you remove, make sure there's no coring in that mount location. Be sure that it's solid glass. Also, don't fill large voids with 5200. You would be well served to have a backing plate on the topside to help protect the structure from impacts on those rudders. If you remove, and if you have large voids within that mount, consider grinding out the old surface, remounting with a cab-o-sil bedding into place, torqued into position....let cure....then remove, inspect for adhesion and cracking, and reinstall with a smaller amount of 5200. When finished, clean and gelcoat the topside so that you can more easily monitor the area going forward.
  14. rtrafford

    rtrafford Senior Member

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    ....the backing plate will help to spread the load over a larger area if you impact your rudder against debris in the water...it's a worthwhile safety upgrade.
  15. Capt Ralph

    Capt Ralph Senior Member

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    Some observations;

    The weight of the rudder is on those pins, resting on the plastic shims.
    In the event of a pin failure, the tiller or next pin would keep the rudder from dropping completely.

    Your picture in post #1 shows in tightening the post gland to reduce leaking, the rudder has been lowered.
    With a gap that large, I would assume your out of packing material (Flax).

    With these pins and weight of the rudder bearing down, Replacing the flax or any gland service is going to be a heck of a chore.

    If your going to take it all apart and want it (IMO) more correct, Replace that top plastic plate with a flange bearing to hold the weight on top of the shelf plank. Now with the pins and plastic shims removed, gland service is a snap anytime.

    Below is the best pic I could find this morning.
    rudder_shelf_a.gif

    Often the rudder shelf plank (in blue) is called the pillow.
  16. cleanslate

    cleanslate Senior Member

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    Why is there a pin in the middle doing nothing from what I see?
    What Ralph said , you have to get the load bearing pin out of the way to install flax packing AND to be able to adjust the packing nuts with the hopes you line up the hole in the shaft for the resting pin to go back into and carry the load...hope you can shift the load to the top mounting plate.
  17. alvareza

    alvareza Member

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    Really appreciate all the advice. The picture really helped.

    Seems like the pins have to go. Only use for the high pin would be to hold rudder up with straps or while working on it. The “extra” shaft below the hull might be due to the fixed position of the lower pin.

    Between the extra shaft length below the hull, the top plastic spacer and shaft above the tiller seems that there is enough shaft length to install the top flange and lock collar.

    What brand/type of post port, bearing flange and collar do you recommend?

    I saw some top bearings described as low profile, any thoughts on these if I am tight on shaft length?

    Once the pins are gone, do I need to fill the holes in the shaft?
  18. Capt Ralph

    Capt Ralph Senior Member

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    I started to think about this and did not like what came to mind.
    Stainless steel has a fault; Crevice Corrosion.

    Filling with epoxy was a thought but I would always worry about a micro drop of moisture getting in some how.
    I would either clean the holes real well and leaving them dry and empty or clean and push water proof grease thru the holes.
    Maybe some others on YF understands what I'm trying to explain and have some better thoughts.
  19. Capt Ralph

    Capt Ralph Senior Member

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    In my past, The yard or prop/shaft shop provided the pillow bearings for new work.
    I've gone to bearing shops with the core and matched up replacements for repair work.

    Closed bearing, zerk fitting, shaft capturing screws like a prop shaft coupler.
    I have no brand recommendations.
  20. Capt Ralph

    Capt Ralph Senior Member

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    Now, the gland.
    Long, long (long) ago, I remember working on an old alloy Striker. The welded in rudder tube tops were corroding away at the bronze gland packing and crumbling away.
    Instead of cutting out the tubes and welding in a new ones, I just cut the tube tops off a bit and installed the LassDrop all synthetic shaft logs.
    Years later with zero maintenance, still bone dry.

    These days there must be a dozen low maintenance shaft log vendors out there.
    Something extra to think about.

    Ah yes, I luv thinking up ways for others to spend lots of their money..:cool::cool: