Outboard for laser sailing dingy

Discussion in 'Sailboats' started by Peter Duck, Feb 20, 2012.

  1. Peter Duck
    Joined: Mar 2010
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    Peter Duck Junior Member

    Hi, some low dingo nicked the aluminium spars off my laser while it was parked at the local club. I have a 2hp outboard not currently being used and was wondering about how I may go about attaching it to the stern of the laser so I could at least use it to go fishing on the lake. Has anybody got any ideas on the most effective was of doing this?? Any links to photo's etc??:confused:
     
  2. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Get a hunk of 3/4" (19 mm) plywood and screw it to the transom, after removing the gudgeons. Set the engine mounting clamp so the ventilation plate is a few inches below the LWL. This is deeper then usual for a powerboat, but necessary on a sailboat conversion. I've done this on several small sailboats and it works well, plus can be easily removed once you find a new set of spars. A 2 HP on a laser will make it really fly. Expect 12 MPH and better, depending on how you can trim her out. A tiller extension handle will help in this regard, so you can move further forward in the hull to keep her nose down. Don't try crisp turns at WOT or you'll find out what happens (quite suddenly) when you over power one of these puppies.
     
  3. Peter Duck
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    Peter Duck Junior Member

    Thanks for the idea, just a question on the ply plate to attach to the transom. What type of screw would you think best? cheers
     
  4. CutOnce

    CutOnce Previous Member

    If I were doing this I would probably put in a little more effort and thinking.

    I would make motor mount that fit over the existing pintles/gudgeons, with a projection that fit the transom deck/hull join of the hull eliminating the potential for movement of the mount. I'd lock down the mount by a clamping mechanism that gripped the hull/deck seam from the sides.

    The hull/deck join on Lasers is pretty strong and easy to use for this. The existing pintle/gudgeons are strong, well mounted and do not require damaging the existing structure and mounts. Once you heat and back out the existing stainless pintle/gudgeon bolts to attach your motor mount, the chances of putting the boat back to sealed sailing condition drop a lot.

    Doing things as I suggest keeps the Laser intact as a Laser. Realistically, it is no more effort to make a detachable motor mount this way than it would be to go the suggested route. I rarely differ from PAR on anything, but in this case a little more effort up front can save you a lot of resale/re-use value later. Laser tubes often show up on Craigslist etc.

    Just a thought, since if the job is worth doing, it certainly is worth doing right.

    --
    CutOnce
     
  5. pistnbroke
    Joined: Jan 2009
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    pistnbroke I try

    using a couple of G clamps ( strong ones) to position your tempary ply on the rear would be a good idea then fix it or not when you are happy
     
  6. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Okay, you got me, I'll admit yanking those gudgeon bolts will be enough of a pain in the butt to warrant a more "CutOnce" approach. Maybe a false transom that hangs on the gudgeons, though I think 2 HP is enough to possably bend them, if used long are hard this way, though "keyed" the flange, as CutOnce suggests, likely stiff enough to prevent major concerns.
     
  7. michael pierzga
    Joined: Dec 2008
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    michael pierzga Senior Member

    The hull deck flange is pretty strong on a laser.

    You might be able to bore two 20mm holes thru the stern flange, then slide 20mm ss tubing thru the holes. Plywood Plank across the top of the two ss tubes and some method like a pipe clamp to the hold the tube ends to the transom .


    Would be nice because it would plug in and out and not violate the rudder hardware
     

    Attached Files:

  8. tom28571
    Joined: Dec 2001
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    tom28571 Senior Member

    Yeah Paul, I think cutonce got it best. The gudgeons should be strong enough to take the thrust of 2hp and lateral loads would be taken by the deck/hull joint. Sounds good to me. Of course we would all like to know what happens when a round hull powerboat makes a tight turn at speed. Hope he is wearing a life jacket. A Laser is so light that he could probably counter the lean-out/capsize tendency by sitting on the inside of a turn.
     
  9. gggGuest
    Joined: Feb 2005
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    gggGuest ...

    Bearing in mind how much hassle the conversion will be and how unsatisfactory the well and everything on a Laser is likely to be for fishing, before you go to all that work might it be worth an ad is some appropriate medium on the lines of:

    "Good Laser Hull: spars have been nicked. Will swap for a reasonable tinny or WHY."

    after all Laser hulls do die, so there's a good chance someone out there needs a less beat up hull and both parties end up with a better craft...

    And come to that anything with more freeboard will be better than the Laser: I've seen photos of a really neat fast runabout converted from an old 14 footer.
     
  10. upchurchmr
    Joined: Feb 2011
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    upchurchmr Senior Member

    I think after you mount the false transom, you should borrow a lawn chair from the DIY-Tri-Guy and mount it over the footwell. More comfortable fishing, much better image cruising at 10MPH on the way to the fishing spot. I'd really like a picture when you finish.
     

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

    The Laser is really a flat bottomed boat with radiused chines Tom. They skid a bit and you either vent enough, slowing the boat dramatically, where it bites and accepts the helm input or you lower centerboard a tad and it does fairly well. A 2 HP can't push it especially fast. A Laser has about 5 HP in it's rig in force 4 wind strengths, so the math isn't especially difficult for a 2 HP. Trimmed properly, he might see low double digits, but likely high singles. The last boat I did this to was a US 1, which is a bit larger preformance dinghy with hard chines. It did about 13 MPH with a 3 HP.
     
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