glassing over foam boat

Discussion in 'Sailboats' started by jbarnhart101, Dec 22, 2015.

  1. jbarnhart101
    Joined: Dec 2015
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    jbarnhart101 New Member

    I have an 11' sailboat, similar to sunfish but solid foam covered in ABS. The ABS was rotten and my son and I literally tore it off the foam in ten minutes. I am going to glass it in epoxy. My question many ounces of glass should I use? Boat won't stay in water and then only in fresh water lakes. And yes, I know it's not worth it...but my dad won this boat selling World Book encyclopedias door to door in the early 1970's so...
  2. gggGuest
    Joined: Feb 2005
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    gggGuest ...

    It all depends on how dent resistant you want the boat to be. Lightweight high performance boats in foam sandwich on a pvc foam core will work fine with 2 layers of 200gsm glass. That's proper woven glass, not chopped strand c***. That might well do for a boat that is treated lovingly, not dropped off the dock. 3 layers might be safer though. Do the sums on different materials, but especially consider how much resin you're going to use. You can save a great deal of money with careful layup technique, and good quality glass may save you money on resin.
  3. bruceb
    Joined: Nov 2008
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    bruceb Senior Member

    keep it light

    It will be a "labor of love" for sure, you could never justify the time and material cost, BUT...
    I assume it is a "Snark". They were sold both covered and as just a piece of foam, the covered ones were almost durable and could sort of sail. They were suited to ponds and protected water. Lots of people started sailing with them, so they definitely have a place in history :) They also got used as pool toys and many met their end when someone jumped from the pool or dock onto it- they usually broke in the middle. :mad:
    Glassing one properly would certainly extend its life, but I have seen some poorly executed examples that were just trash and a complete waste of time and materials. I think the question for you is how good are your glassing skills. It would be best if this was not your first project ;)
    The foam is pretty dense, but the original plastic coating was resilient while glass/epoxy will not be so requires a little thicker layer to survive. 4 oz to 6 oz is plenty on the bottom, but the deck seating area could use about 10oz total. I would use peel ply and try to keep the weight gain to a minimum.
    Good luck!
  4. philSweet
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    philSweet Senior Member

    I think I'd trowel on a layer of epoxy putty first, to give you something to work with. You can't sand the foam, and you can't sand the fiberglass later. Very light "cool whip" with lots of bubbles and just a little cabosil. Apply with a toothed trowel and then smooth it over. Then sand very carefully by hand unless you are super amazing with power sanders. I'm talking 1/16" here. You have to fill all the divots because the woven glass won't fill a hollow on that little boat. I think fully wetted and filled 4oz over this would do. You'll get laps on the centerline and sheer. You may still want more glass on the sheer, depending on what flavor of Snark it is.

    PS, I through my '74 World Book encyclopedia away 1 month ago. I'm surprised a Snark outlasted the books.

  5. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    I 'glassed a foam Snark like thing several years ago for a buddy of mine. I faired the hull first, as Phil recommended, as it's a lot easier to fair the foam, than risk cutting into the fabric after th it's skinned. I used 6 ounce cloth and it held up fairly well, but didn't take much abuse before the foam got busted up, under impacts.
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