1980 four winns - wet transom

Discussion in 'Fiberglass and Composite Boat Building' started by atengnr, Nov 19, 2019.

  1. atengnr
    Joined: Jun 2006
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    atengnr Junior Member

    No, no I have no issue working in a tight area like this. The transom extends well below the sole away from the bilge, requiring cutting away the floor to gain access, and also theres the issue of the splashwell removal. Youre saying that its easier to cut the cap off, cut away a section of the floor then to do from outside ?
     
  2. atengnr
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    atengnr Junior Member

    Heres pics just to be sure.
     

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  3. atengnr
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    atengnr Junior Member

    and LOL, dont laugh at the Force motor on there. I bought for fun, as Id never owned one, and I must say that it runs great. If it blows up no biggie, Ill put something else on there (OMC guy by nature).
     
  4. Blueknarr
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    Blueknarr Senior Member

    I've recorded many transoms in my shop.

    Haven't had to remove the cap or splash well yet.

    Even removing inboard and interior is less work than opening up the outside.

    Only operated from outside once. The boat was rear ended by a car. The structural elements of the repair took less than a week. Followed by three weeks of cosmetic work.

    Yes from the cramped interior is faster.
     
  5. atengnr
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    atengnr Junior Member

    Oh wow OK. This splashwell is pretty deep, so Im not sure how I could slide the new piece of transom in there. How much of the floor do I need to remove?
     
  6. atengnr
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    atengnr Junior Member

    See how i could slide a new core in here without cutting splashwell?
     

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  7. Blueknarr
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    Blueknarr Senior Member

    Some thoughts you may have not considered.

    The core doesn't have to be a single piece. It can have both vertical and horizontal seams.

    The inner FG skin can also be patchwork.

    Any removed sole may be reused. Doesn't automatically need to be replaced.

    However, rotten soles, stringers and sodden post catastrophe buoyancy foam are the frequent companions to a rotten transom.

    Removal of the aft portion of sole facilitates the inspection of these components.

    One to three feet of sole removal usually allows better access to transom.

    Cut a stick to the length of the tallest piece of replacement core. Mark sole where it wedges. Add some wiggle room. That is your cut line.

    Ps
    In the previous example; the structural repair was performed from the inside. Then the damaged exoskin was removed for replacement.
     
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  8. atengnr
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    atengnr Junior Member

    Thanks. So i could have vertical seams of wood for the coring?
     
  9. Blueknarr
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    Blueknarr Senior Member

    Most definitely. My personal boat's transom is divided into three planes. So three pieces of core.
     
  10. fallguy
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    fallguy Senior Member

    You can seam the core, but I would avoid seaming the core in the lines of the engine bolts.

    So no core seaming on or near the two vertical engine lines and no horizontal seams in the horizontal lines. While you could probably get away with it; it may result in stress cracking someday. As long as you are avoiding core seams there; you might as well move off those lines an inch or two each way. You still have plenty of places to seam multiple pieces.

    If you don't one piece the core; no core seams would overlap if you do multiple cores to get to your final thickness; same reasons.
     
    Last edited: Nov 23, 2019
  11. fallguy
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    fallguy Senior Member

    If you remove the sole; it is a good idea to avoid removing the sole all the way to the port and starboard edges. A number of reasons...

    1. The remaining edge say 2" can be used to glue a cleat onto the bottom for when you want to reglue the cutaway sole section.

    2. There is less risk of punching through the hull.

    3. It may be easier to remove a narrower piece vs wider.
     
  12. fallguy
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    fallguy Senior Member

    Work under the cap and well if possible and no rot that high as BK suggested.
     
  13. atengnr
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    atengnr Junior Member

    So can i just cut out a large square piece of rot and just epoxy in a new piece despite the seam running through thickness of ttanslm?
     
  14. fallguy
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    fallguy Senior Member

    It would be better to stack the laminates with a varied overlap. But you can get away with the full core as long as it is installed well (bedded all sides) and glassed well inside. You can even purchase a commercial product called gel magic that is sort of designed for bedding the core as well.

    When you decore, I strongly recommend using a carbide oscillating tool or a small circ saw with the blade marked or the depth set to avoid cutting into the exterior glass.

    SilverTip GelMagic https://www.systemthree.com/products/silvertip-gelmagic-non-sagging-epoxy-adhesive
     

  15. Mr Efficiency
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    Mr Efficiency Senior Member

    All I see here is advice to get involved in a mountain of work. on an old boat that is worth next to nothing. Wouldn't dream of it. Safety is job #1, if the concern is of a structural failure that might sink the boat, the answer that covers all contingencies is adequate, properly placed buoyancy material. Maybe this boat already has buoyancy foam installed, that can be easily enough checked by drilling a few holes where it might have been placed, You can use a hole saw of a size that will then allow fitting of flush fitting, screw in ports. If there is no foam, those holes gives the opportunity to pour some in. Beyond that, I would shore the existing transom up from the inside, as outlined earlier, and forget it. And Blueknarr, as for spending three weeks work on the exterior cosmetics of a transom replacement, puhhlease !
     
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