U-bolt fitting - bedding threads in epoxy

Discussion in 'Boatbuilding' started by elhix, Feb 16, 2010.

  1. elhix
    Joined: Feb 2005
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    elhix Junior Member

    My plans include u-bolts for a bridle at the bows. They have their threads embedded in epoxy in a hardwood block that is in turn behind several layers of glass. I have added a similar feature to the two sterns for a drogue bridle.

    My question is: does embedding u-bolt threads is epoxy provide the strength necessary?
  2. jehardiman
    Joined: Aug 2004
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    jehardiman Senior Member

    Get a copy of "The Gougeon Brothers on Boat Construction" book. It has an extensive discussion of how to design an epoxy only fitting like that: required hole size, hole depth, strength, etc.
  3. Petros
    Joined: Oct 2007
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    Petros Senior Member

    IF the joint was designed and built properly it should hold up just fine. If there is some reason to think this joint will fail? Is there a history of this joint failing? OR are you not confident you can built it properly?

    It can also be more durable than a bolted joint, where it can trap moisture and allow rot in a place that is hard to inspect.
  4. elhix
    Joined: Feb 2005
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    elhix Junior Member

    I've no reason to believe the joint as described on the plans will fail and certainly feel happy to build it, I was just looking for opinion on this type of fitting rather than the usual bolts and backing plates.

    Jehardiman, I should have bought the Gougeons book back in the beginning... I'm reluctant to now as it'll only tell me what I could have done better. Going to have a look on amazon though.

  5. lewisboats
    Joined: Oct 2002
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    lewisboats Obsessed Member

    I would certainly not consider the threads in epoxy to have the same strength as a backing plate...but the fact that you are only using this system for the bridle ends...you should be able to get away with it for a long time. The fastening is stronger than the rope and the rope will absorb shocks in the system so you should be ok.
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