Fairing Core cel bead and cove

Discussion in 'Boatbuilding' started by brokensheer, Dec 8, 2010.

  1. brokensheer
    Joined: Jun 2009
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    brokensheer Senior Member

    I have a 17' hull planked in 1/2" core cel, I have been longboarding it and it goes well , I was looking at someone else who is doing the same and knocking down high spots with a 8" round sander your thoughts?
     
  2. War Whoop
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    War Whoop Senior Member

    Forget it,Long board the thing.
     
  3. PAR
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    PAR Yacht Designer/Builder

    Dito, you can't fair a hull with an orbital sander, you have to longboard. This said, if you are quite skilled with a DA, you can knock the tops off high spots (after their identified), but ultimately leveling these will require the longboard.
     
  4. brokensheer
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    brokensheer Senior Member

    Thanks She is a very shaply hull and I have her very close to fair on the jig the planks I used are 2 1/2" should not take too long!
     
  5. Stumble
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    Stumble Senior Member

    Just to chime in, the local bottom guy here (who is also the equipment guy for the US Olympic team) uses a orbital sander, and an electrical planer on really bad bottoms. But then he also cuts out templates with a sawz saw. Of course all of this 'rough' work is then followed up by hand long boarding.

    The reality is that if you have the skill, and know exacally what you are doing, you can use pretty much any tool you want. But the more agressive the tool used the larger the likelyhood of taking off too much material, and having to start over. Personally I use long boards and if the work takes more than that it goes to a pro.
     
  6. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Orbital sanders follow too closely to the surface to be effective at knocking down high spots. These sanders are finish sanders and intended to smooth the surface, not fair it. There's a huge difference between smooth and fair. Smooth is something you can feel, on the other hand, fair is something you can see, though unskilled hands can't feel it (skilled hands can). You can have a really smooth, but unfair surface, like slightly wavy, but clean glass. If you use an orbital or DA sander, you'll get a smooth surface eventually, but it will not be fair unless you have way more experience then I.
     
  7. rwatson
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    rwatson Senior Member

  8. Herman
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    Herman Senior Member

    Yes, these are great.

    For initial high spots: take something light and straight (such as an old fluorescent light) and shift this over the surface, holding it in the middle. At high spots the FL will tilt. Mark this spot with a pencil. Work the whole boat that way.

    Now you have the boat marked wil pencil, and you can sand those marks. Leave the rest alone for the longboarding. This at least saves some time and effort.
     
  9. War Whoop
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    War Whoop Senior Member

    Years back we made that windshield wiper mechanism type sander to get away from a sanding batten it worked ok but a carefully selected acrylic plastic strip always worked better with PSA sandpaper.

    also have an old electric half sheet with a metal plate for a base pad it sands dead flat, Hutchins Straight line, DAs ,Rasper ,Eliminator, and the common 8" DAs with different pads.

    Nothing comes close to a large Metal file in the right hands.
     
  10. Steve W
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    Steve W Senior Member

    Im kind of partial to fartrock and its very cost effective,of course you still need skill. Oops,your not going to be using fartrock on the core,sorry.
    Steve.
     

  11. waikikin
    Joined: Jan 2006
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    waikikin Senior Member

    Thanks for posting, Flexicat makes fairing fun;) :rolleyes:
    All the best from Jeff.
     
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