Wood/Epoxy Beams or Foam/Glass Beams?

Discussion in 'Boatbuilding' started by CatBuilder, Aug 14, 2011.

  1. CatBuilder

    CatBuilder Previous Member

    It seems every time I try something "more advanced" out, I like it a lot better
    than the other way of doing things.

    Now, I am looking at the beams. On one hand, I can make them from plywood and
    sitka spruce framing.

    On the other hand, I could make them from foam and various glass laminations.

    Which would you want on your boat and why? My understanding of strengths are
    these:

    Wood/Epoxy:
    The Good-
    *Can withstand more cyclic loading without losing strength
    The Bad-
    *Good construction dependent on humidity
    *Complicated things like laminating sitka spruce together and affixing in
    patterns inside beams
    *May rot someday if I didn't do a great job with my epoxy coating
    *Heavier
    *Sawdust
    *I suck at working with wood and doing scarf joints

    Foam/Glass:
    The Good-
    *Easier to make - just lay out foam flat, cut glass layers to shape and infuse
    *Weighs less
    *Can be infused easily
    *Clean work
    The Bad-
    *Much more expensive
    *Plans call for lots of uni, but maybe I can substitute some triax and biax in.

    Which would you want on your boat and why?
     
  2. rberrey
    Joined: Oct 2010
    Posts: 561
    Likes: 61, Points: 28, Legacy Rep: 112
    Location: AL gulf coast

    rberrey Senior Member

    If you have to buy more foam, you may get a better deal with a case price. I ruled out the use of wood for the above reason when I bought my foam. Whatever higher cost I payed could,nt have been that much if shipping were figured in, and I hope that little extra was worth the weight savings I plan on getting. rick
     
  3. Brian@BNE
    Joined: Jan 2010
    Posts: 262
    Likes: 13, Points: 18, Legacy Rep: 151
    Location: Brisbane, Australia

    Brian@BNE Senior Member

    *Less weight has to be good, particularly for a cat.
    *at some point there's likely to be stuff screwed or bolted on, piercing your epoxy seal and opening the door to wet wood and rot. Maybe not a problem for you though as you know the risks.
    *Could you have some embedded aluminum sections to improve strength characteristics and reduce cost?

    ....welcome back. Any recent photos, how's it all progressing?
     

  4. CatBuilder

    CatBuilder Previous Member

    I guess it's unanimous. Nobody, and I mean nobody, on a couple of places I asked this question thought I should do anything but proper glass beams.

    I was leaning that way as well.

    Rick: Better prices on cases? I buy foam by the semi trailer load! ha ha ha ;) Seriously, I think I got 6 double sheet cases last time.

    So yeah, foam/glass beams it is. Thanks for the input.
     
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.