Which epoxy for my catamaran build?

Discussion in 'Materials' started by GrahamR, Feb 3, 2016.

  1. GrahamR
    Joined: Nov 2015
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    Location: Cornwall UK

    GrahamR Junior Member

    Hello All,

    I’m currently designing and building a 4.5m long sailing catamaran, for those in the know think smaller version of the “A Class”. So, high performance (hopefully) and maybe capable of flying once I’m happy with the normal (displacement) sailing characteristics. Anyway, this calls for light hulls, mast and crossbeams etc. that can also take relatively high loads.

    As of now I have a basic plug constructed out of MDF and PU foam and I’m about to start finishing this so that I can take moulds from it. I have also lined out my workshop with 75mm celotex insulation so I can easily control the temperature and humidity.

    My idea is to not go too exotic with the materials for the hulls and use an e glass biaxial / core cell / epoxy laminate and reinforce this as necessary to take the loads from the rigging, crossbeams etc. The mouldings will be vacuum bagged, something I have researched quite a bit, but have not actually tried yet.

    My question is, what type of epoxy should I use for building the hulls, or is vinylester resin a good alternative? I would like to avoid having to do any high temperature post curing if possible, and believe I can heat the workshop to about 30 degrees C if needed. I’m aware that the type of epoxy can have some influence on mould materials also, so some suggestions for what resin to use on these would also be welcome.

    As you’ll realise my experience of modern composites is limited, I worked in boatyards back in the days when we used polyester and chopped strands and have more recently done some cold moulded ply / epoxy boat projects.

    All suggestions gratefully appreciated.
     
  2. Steve W
    Joined: Jul 2004
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    Location: Duluth, Minnesota

    Steve W Senior Member

    The only reason to choose epoxy over ve that I can think of is that the smell of ve which is the same as polyester can cause problems with neihbors, if that's not a problem the I would go with ve.

    steve
     
  3. ebnelson
    Joined: Nov 2013
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    Location: usa

    ebnelson Junior Member

    People seem to like the MAS epoxy quite a bit. I've been working with Applied Poleramic epoxy for many years and have been happy with it.
     
  4. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    I think epoxy is much easier to use than the styrene based options.

    The major formulators will be twice (or more) as much as the discount formulators. Try Marinepoxy and Bateau.com, also RAKA and Progress (epoxyproducts.com). These will be some of the least costly, all having similar physical properties of the major brands.
     
  5. GrahamR
    Joined: Nov 2015
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    Location: Cornwall UK

    GrahamR Junior Member

    Thanks for the suggestions, whilst some of these are available in UK the pack sizes are small hence expensive. I've decided to use Sicomin 5550 which appears to meet all my criteria and has a mix and match selection of hardener, also not needing high post cure temperatures . Does anyone have experience of this?
     

  6. PAR
    Joined: Nov 2003
    Posts: 19,133
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    None of the brands I've listed have high post cure temperatures. These are all room temperature cure epoxies and post curing isn't necessary. I don't have person experience with Sicomin, but it appears a suitable goo. For my needs, I'd likely use SR 8450, instead of 5550, but with your general ambient temperatures, maybe 5550 is a better choice.
     
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