'glass covering

Discussion in 'Fiberglass and Composite Boat Building' started by billjoat, Feb 25, 2009.

  1. billjoat
    Joined: Jan 2009
    Posts: 10
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    Location: new bern, nc

    billjoat Junior Member

    I'm currently building a Spira 24' chesapeake stretched to 26'. Ply on frame construction. I've 12oz biaxed the seams and am now proceding to cover the hull. Is 6oz cloth a suitable glass along with epoxy for the covering or do I really need to step up to something like the 12 oz biax like I used for the seams? I'm thinking a 6oz cloth layer with an extra layer of epoxy will smooth it out rather nicely for waterproofing and I do not need the extra strength of the biax since its framed the way it is.

  2. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Biax is a lot harder to smooth out the regular cloth, use the 6 ounce. 6 ounce is fairly light weight stuff, but will offer abrasion protection and water proofness. I generally use 8 ounce and a minimum hull sheathing, unless it's a bright finish, where I use 4 ounce.

    A 12 ounce sheath is pretty thick and heavy. I wouldn't bother unless you expect fairly rough usage.

    A single layer of biax on the outside seams is fine, but do yourself a favor and use a healthy fillet (50% silica, 50% milled fibers is a good mixture) on the inside and a couple of staggered layers of biax on these seams. The inside seams will be taking the brunt of the loading, so make them stiff.
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