Fixing to a hollow gunnel

Discussion in 'Fiberglass and Composite Boat Building' started by valvebounce, Jul 16, 2015.

  1. valvebounce
    Joined: Dec 2010
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    valvebounce Senior Member

    My boat is double skinned,I suspect the gunnels are hollow.
    I would like to fit a bow roller for the anchor.Is there a type of expanding plug that will do the job.The boat is only 14ft and weighs less than 200lbs.
    (Skipper dinghy)
    There are "U" hoop fittings (8) along the gunnels,which were for the ropes when it was a sailing dinghy.I am not using it under sail,just with an outboard.
    The mast and dagger board have been removed.There are fittings in place for rowlocks,which I think were originally incorporated.
    I am trying to avoid drilling or cutting the gunnel if possible,although it will need to be drilled to take the bow roller.
    If need be,I can cut and reinforce the gunnel at the bow,but I would prefer not to.
     
  2. Jamie Kennedy
    Joined: Jun 2015
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    Jamie Kennedy Senior Member

    I would drill holes for bolts as though it wer solid and then inject in some epoxy with some filler just to seal it off not so much for reinforcement. Should be strong enough you just don't need water getting in there. Where will anchor actually attach to, once anchored.
    I would put a cleat somewhere around the front of the centreboard trunk. Central.
     
  3. alan white
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    alan white Senior Member

    Why do you need a bow roller for such a small boat? The problem of chafe shouldn't be an issue----- if you simply clip or tie to a bow eye you won't have to worry about the rail at all. The anchor shouldn't hang from the bow like on cruisers. Too much weight forward, it will affect performance. If you carry the anchor in the cockpit you won't have to go forward to drop it. Attach it to the bow eye afterwards.
     
  4. PAR
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    PAR Yacht Designer/Builder

    The problem with this arrangement is just what you're experiencing, no meat to attach things, just a void, under a thin skin. If you inject epoxy, you'll find you can pump in a gallon of goo, just to have it run down the inside of this void and spread out into a pool. If thickened enough you might end up with a mass of goo where you need it, but because you can't see it, you'll never know. Lastly, because you can't prep the inside surface, so the goo can bond well, again you'll never know, until the fasteners pull out and drop the roller assembly in the drink.

    [​IMG]

    If it was me I'd cut an access hatch in the forward face of the forward cockpit. I'd use a multi tool to keep the cut line neat and fine, so I could reuse this piece as the hatch cover, after adding some trim to finish the edges. Once you've opened up the area, you can bond in backing plates, which could be plywood or metal, to receive the fasteners (through bolts).
     
  5. valvebounce
    Joined: Dec 2010
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    valvebounce Senior Member

    Thanks for your replies Gentlemen,all are noted and appreciated.
    The reason I want to install a bowroller is because the paintwork chafes easily,and for the ease of using the anchor.
    If I need to motor over the anchor to free it,which is quite possible off the Welsh coast,I thought the extra strength would help.
    At present,I will need to consider the seabed carefully,and although I would take care to consider it,it would restrict where I drop anchor more than I would like.
    Many thanks for your interest.
    V
     
  6. valvebounce
    Joined: Dec 2010
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    valvebounce Senior Member

    You have hit the nail on the head as usual PAR.
    The boat in the pic you sent is exactly the same as mine,even the colour.
    The only difference being mine has no mast.
    There is very little to fix to on this boat,the stern hatch cover had no fixings,
    apart from two loops to thread a rope through.I attached two small cleats to the cover,and used elasticated loops to hold it down.Apparently it is a common problem,with hatches being lost while trailering and at sea.
    I used a waffle type rubber backing on the underside,which keeps it somewhat more watertight and gives a good seating.I attached two handles which makes it more convenient to fit and remove.
    Thanks for your interest
    V
     
  7. SaltOntheBrain
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    SaltOntheBrain Senior Member

    Togglers will work.
    And they come in 305 Stainless.
    Think toggle bolt meets zip tie.
    LF
     
  8. SaltOntheBrain
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    SaltOntheBrain Senior Member

    Pic didn't attach.
    Here it is
     

    Attached Files:

  9. valvebounce
    Joined: Dec 2010
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    valvebounce Senior Member

    Many thanks for your interest,I will see if I can locate a source over here for them.
    Did a 6 mile round trip on the river weaver in Cheshire yesterday,it was a real pleasure.
    Thanks again
    V
     
  10. SukiSolo
    Joined: Dec 2012
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    SukiSolo Senior Member

    Alan is right, you should not need a roller. A bow cleat or guide is enough. One way is to make a fibreglass one in situ, with a sheet of polythene to stop it sticking. You just needa semi sacrificial rubbing surface (and guide). If you can actually work aluminium well enough, you could use that.

    Otherwise, go with PAR's suggestion and put some meat into the bow area. If you ever winch the boat onto a trailer with outboard, you should definitely use this latter suggestion. I suspect the toggles will work loose over time, the layup on those Skippers is not that great.
     
  11. PAR
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    PAR Yacht Designer/Builder

    Those toggle bolts will point load the laminate and bust it up pretty quickly, without some sort of backing plate for them to bear against, though in the short term they'll work. Given the size of the hole they need to be installed, you might just think about inserting some plywood (through the hole) and bond it to the underside of the deck flange. At least you'll have something to spread the load, besides the thin laminate, which is probably just mat.
     
  12. valvebounce
    Joined: Dec 2010
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    valvebounce Senior Member

    Thanks for your interest gentlemen.
    I think PAR'S suggestion is the way I will go.
    I can handle the reinforcing,
    I suppose,like with most jobs,a quick fix is only a temporary fix.
    I actually bought the bowroller for my other boat,so a bit of a reshuffle might be in order.
    V
     
  13. SukiSolo
    Joined: Dec 2012
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    SukiSolo Senior Member

    It is - a classic 1960s' type CSM hand layup, none too clever by modern standards and wafer thin in places. At least in my experience of dealing with Skippers.....;)
    Spot on PAR, if Valvebounce can pad/reinforce to the returns, and stiff parts he should have no problems.
     
  14. latestarter
    Joined: Jul 2010
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    latestarter Senior Member

    If you turn the boat upside down and maybe tilt it a bit bow down on trestles or other support, to allow you to work on the inside, it might help when bonding the reinforcement.
     

  15. PAR
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    PAR Yacht Designer/Builder

    Rather then rolling the boat over and hope gravity will do the work for you, simply drill a very small hole in the reinforcement piece, so you can use a length of wire to hold the piece, while the goo cures. Just knot the wire, push it through the hole, butter it up with goo, insert the reinforcement, then using the wire (or string or coat hanger) brace, block weight or duct tape it to apply a bit of up pressure as the goo does it's thing.
     
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