Catamaran beam construction

Discussion in 'Multihulls' started by rturbett, Jul 11, 2021.

  1. rturbett
    Joined: Aug 2005
    Posts: 193
    Likes: 4, Points: 28, Legacy Rep: 35
    Location: FINGER LAKES, NY

    rturbett Senior Member

    Well, I was originally not planning on doing the beams- so glad I reconsidered...... this was the rear beam.
     

    Attached Files:

  2. fallguy
    Joined: Dec 2016
    Posts: 6,784
    Likes: 1,389, Points: 123, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    If that much glass and resin were done in epoxy; that wood never wudda rotted
     
    Last edited: Aug 10, 2021
    bajansailor likes this.
  3. redreuben
    Joined: Jan 2009
    Posts: 1,956
    Likes: 203, Points: 63, Legacy Rep: 349
    Location: South Lake Western Australia

    redreuben redreuben

    I was going to say with that much glass and resin the wood is barely relevant !
     
    rxcomposite and bajansailor like this.
  4. rturbett
    Joined: Aug 2005
    Posts: 193
    Likes: 4, Points: 28, Legacy Rep: 35
    Location: FINGER LAKES, NY

    rturbett Senior Member

    love the thoughts- FYI- the picture is a cut through right at the end where it was mounted to the hull- the glass you are looking at was what was used to attach it to the hull. FYI-I am trying to figure out what wood was used. We normally use mahogany
     
  5. fallguy
    Joined: Dec 2016
    Posts: 6,784
    Likes: 1,389, Points: 123, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    Looks like a close grained hardwood from here. Mahogany put up wet would rot like that on the inside or if the resin were polyester and not sealed.

    Main thing is to avoid putting it up wet and full encapsulation..
     
  6. Steve Clark
    Joined: Jul 2004
    Posts: 221
    Likes: 26, Points: 28, Legacy Rep: 163
    Location: Narragansett Bay RI

    Steve Clark Charged Particle

    There isn’t any rule of thumb guidance for that can be given for this kind of thing. You have to actually calculate the strength and stiffness of the wood structure and design the composite piece to replace it.
    My understanding is that Dick Gibbs was a hack and butchered some pretty good designs by using the cheapest materials and sleaziest techniques. Your dedication to the Shark design is the only thing that has preserved the crap he sold.
    I think that doing a careful job building the wood beams is likely the best option. Wood is actually a pretty good material for the design, and Rod was no dummy.
    SHC
     

  7. rturbett
    Joined: Aug 2005
    Posts: 193
    Likes: 4, Points: 28, Legacy Rep: 35
    Location: FINGER LAKES, NY

    rturbett Senior Member

    Well, it would really help me if you could be clearer on your feeling towards Gibbs....... I haven't rebuilt any of his boats- I'm working on a set of English hulls now, and next in line is Linda Rogers boat, a wooden one that was the inspiration for (her recently deceased )husband John to build the series of Cedar Sharks.
    I have taken apart a few Gibbs boats for the hardware. They are heavy.
    Rob
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.