Tube Shaft inspection and leak repair

Discussion in 'Motorsailers' started by forever young, Jul 29, 2012.

  1. Frosty

    Frosty Previous Member

    Sure,--- there all sorts of ways one can procrastinate.
     
  2. forever young
    Joined: Jul 2012
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    forever young Junior Member

    Procrastinate

    procrastinate, yes I know, I was in NY for 10 days and now I'm back. So I have to get started doing something. Yard wants me to get a survouer to advise them how to proceed with the repair? Also to document, but I don't know what there is to document until you can see and remove the tube!
     
  3. forever young
    Joined: Jul 2012
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    forever young Junior Member

    What are your thoughts on using schedule 80 HD PVC instead of any metal.
    Then glass in the PVC with 1808 glass and epoxy resin. No dealing with threads and fittings, I'm taking your advice and removing the floor making a large hatch
    which will basiclly expose the entire concrete area. Then, remove all concrete on the top of the tube, replace with the PVC ( if you think it's better ) I know it will save me money and never rot, rust, etc. Then leave the concrete out for good, other then what's under the tube. I added photos of the area and also the residual damage I mentioned. Bulkheads and sole joints are between galley and head. Again this is from boat bottoming out.
    The other floor area with open hatch is what will be removed and then made into a large pair of hatches when the job is done. Thanks for all your advice and input. Steve
     

    Attached Files:

  4. Frosty

    Frosty Previous Member

    Taking photographs and posting them on a forum where people do this for a living seems strange to me. Now I dont want to be rude so please forgive my English Northern frankness but put the camera down and get on with it will you.

    You might want to sheet up the boat or cleaning will take as long as it takes to do the job.
     
  5. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Your disdain for convention is always refreshing Frosty, though I'm glad to see the images, myself.

    PVC is a fairly common shaft tube material, though I don't like it, mostly because 'glass, regardless of resin system employed, doesn't stick all that well to it. In this application, the loading is quite light and likely the reason it's used. I'd rather see a 'glass tube used. Bond issues are eliminated and it's equally as inert as PVC. A 'glass tube is easy to make and install too.

    If making a 'glass tube, don't use 1808 with epoxy, just use cloth or biax. Use a piece of PVC tube as a mandrel, but first cut it length wise, on a table or band saw. Use a bead of silicone or hot gun glue or automotive "Bondo" to reattach the PVC pipe halves together. This permits you to separate the halves when necessary after wrapping with 'glass. Wax (regular car wax) up the exterior of the tube and apply cloth in a spiral down it's length. Overlap the next wrap of fabric, covering the seams of the first and apply as many layers as you think necessary for the tube's stiffness. When ready to remove the tube, you should be able to twist the hot glue or silicone or Bondo bond lines between the two halves enough to shear them clean. Remove the halves and you have a tube, that can be bonded in place.
     
  6. Frosty

    Frosty Previous Member

    PVC stern tube ??? How will you locate the brass sleeved cutlass.

    I want to see the hole its going in first.

    Stainless is my choice pre threaded at the top to screw on the stuffing box.

    With a grease nipple just behind the stuffing box the inside of the tube will never corrode. With shaft fitted fill it with grease till it comes out the cutlass.

    You will not have leaks from that.

    Looks from the pics that the rudder will need to be un bolted and you have a lovely shaft log in bronze there. the new tube should be screwed in to that.

    Youlle see when you git all on the floor.
     
  7. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    There's no cutlass on this boat Frosty, just a stern bearing and a tube that connects it to the stuffing box. The tube can still have a zerk installed inboard, behind the stuffing box, though this frowned upon now as they slowly leak petroleum products into the water. The tell tail rainbow, can cause problems in certain locations.
     
  8. Frosty

    Frosty Previous Member

    QUOTE=forever young;570870
    I recently purchased a 1983 Island Trader
    I just has the shaft and cutlass removed and replaced with new ones done by the boat yard.
     
  9. forever young
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    forever young Junior Member

    You make it sound easy. I'm handy but no experience with glass or this area of the vessel in general. Wish you lived in Stuart LOL.. Frosty, I know you are tired of hearing about my tube and related saga...You guys are all great.
    I wish this yard I was at know what to do instead of asking me what to do.
     
  10. PAR
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    PAR Yacht Designer/Builder

    You are 3 hours away from me on a good day.
     
  11. viking north
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    viking north VINLAND

    Correct me if i'm wrong here -- why all the discussuion on replacing the tube. Is it because you visualize having to do it in order to remove the concrete below it or you suspect the leak is below it. In either case you don't know for sure until you start removing the concrete or have you removed enough to determine so. If so possibly you can solve this problem by cuttin off the present tube in two places--one forward and one aft leaving two stubs remaining attached. This will allow you access to the inside bottom of the keel. When your work is completed in the area below the tube simply glass the cut out piece of tube back in place. This is not rocket science i've done it many many times. PAR is 100% correct plastic pipe and resin do not bond with the added problem of the expansion rate of plastic pipe. This is a job you can handle and with photos we can guide you thru it. If you are in great doubt why not spend $1000 or so and have it done by a professional -- at this stage you need to eliminate this area of damage and move on to other structural concerns. Recall I said to make use of a good designer/surveyor/builder together or seperately , heed that advise and as much as I dare to admit it I have to agree with Crusty Old Frosty, you have to get on with it. (sorry Frosty needed to make a point) :D

    P.S. Thought i'd better add this-- If you decide to cut out a section of tube, don't do what I did after 12/14hrs. of digging out the ballast and using a mini grinder zip blade cut into the tube without completely removing the shaft. Lost most of my profit on that job :mad::mad:
     
    Last edited: Aug 14, 2012
  12. SamSam
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    SamSam Senior Member

    I think the tube is encased in concrete.

    You can buy ready made fiberglass tube. Maybe you could remove the two metal flanges and put a smaller tube in to line the old one, glass it at both ends, reinstall the flanges and leave the concrete.
     
  13. viking north
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    viking north VINLAND

    Encased in concrete certianly changes that plan . However as many have posted glassing in a new FRP tube is no big deal. Correct you are, FRP tubes are available in a multitude of diameters thru just about any of the marine suppliers.
     
  14. forever young
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    forever young Junior Member

    It's being suggested to me when the vessel fell down and forward, then bottomed out on the sea bottom, the engine like everything else in the boat would have tried to move up and forward. The shaft is attached to the engine which is inside the tube. This huge stress would have caused the tube and shaft to stress and also pulled on the shaft in an upward motion. I now have two survoyers opinion that this is what happen and caused the concrete to fracture and tube to stress. What do you guys think? Repairs, removal start this coming week after the bad weather has left.
     

  15. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Well, we all pretty much think the concrete needs to come out, to see what's going on to the laminate, tube, tabbing etc. A tedious job, but not too painful, except for flying bits of concrete. Once things are cleaned and exposed, you'll have a much better clue as to the extent of the damage.

    Your inspections are making reasonable assumptions, but more importantly than the up and forward motion of the heavy hardware, during the initial impact, is the down and back motion these same elements took, as they came to rest. These up and down accelerations of these masses, are going to rip tabbing and fasteners pretty easily. With the concrete out, you'll see how much, but it'll be difficult to guarantee precisely when this damaged occurred.
     
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