Page 2 of 8 FirstFirst 1 2 3 4 5 6 ... LastLast
Results 8 to 14 of 51
  1. #8
    The first thing to say about this issue is that it's a perfect one for hot air on a forum.

    In the overall scheme of things it's also pretty irrelevant to most people – as going fast will be about a huge number of things, and most of those will be well ahead of what paint finish you have.

    But I was brought up as a dinghy racer and we were always told that a matt finish was in theory faster because you could see that the water would run off it more easily. With a gloss finish, water tends to form globules, rather than run off in an even sheen.

    If you're worried about this then I'd say don't be. The gloss finish might look prettier if done well.

    The true advantage of a matt finish is you can get the hull surface itself really flat – and to do that you sand by hand, wrapping sand paper around a flat block of wood and then you work parallel to the flattest direction – usually working along the rocker line. Starting with a medium grade aluminium oxide paper you then work down to a fine grade of paper – usually 1000 grade wet-or-dry by the end.


    But would I sand down my glossy machine-sprayed rails just to allow better water release? No I wouldn't. Would I sand a glossy fin to have a matt finish? No I wouldn't.

    Maybe world cup racers would.
    Now back in the UK.

  2. #9
    Senior Member Gorgesailor's Avatar
    Join Date
    Dec 2009
    Posts
    502
    Quote Originally Posted by Wing 11 View Post
    When I was kid ,they all polished saling boat..

    On the other hand, the theory goes that if the imperfections are well within the viscous sub-layer then it shouldn't make any difference between matt and polish,because water velocity on surface is allways zero/not moving.
    This is what I was told by Larry Tuttle(inventor of tuttle box & fin builder etc...) - basically the boundary layer is no thicker than surface texture of 320grit sandpaper so he said that going much finer than 400 was a waste of time. Not sure if it was true but I do know that the difference is virtually undetectable, which is why it is still considered debatable.

  3. #10
    Senior Member mark62's Avatar
    Join Date
    Oct 2004
    Location
    West Kirby
    Posts
    384
    Not sure about other manufactures, but starboard finish their slalom and speed boards with 1200 grit wet n dry.

    i tried polishing a speedboard (and fins), felt crap, sticky and prone to spin outs. Plus they were slower according to my GPS.

    I don't think you can comparing the finish on boats, ski's etc with windsurf boards, they are worlds apart in how they work.

  4. #11
    Senior Member Gorgesailor's Avatar
    Join Date
    Dec 2009
    Posts
    502
    Quote Originally Posted by Wing 11 View Post
    boundary layer must be thicker then sandpaper texture,if you wont that imperfections of texture do not touch moving water

    Fanatic all boards are matt ,even wave

    Carbon art comes with teflon polish
    Yes, this is what I meant - not sure if it is accurate but makes sense. Honestly, this is a 30 year old question even in windsurfing. I don't think there is any conclusive proof either way. More seem to think matte is faster so this is what prevails. I don't think it matters more than .1%

  5. #12
    Senior Member Gorgesailor's Avatar
    Join Date
    Dec 2009
    Posts
    502
    Quote Originally Posted by Wing 11 View Post
    this explanation with vortices is not logical/intuitive to me,but maybe is correct..the time will show
    (lots of theories failed)
    The thing is it may remain theoretical because the observed "real world" difference seems to be negligible.

  6. #13
    Senior Member
    Join Date
    Nov 2009
    Posts
    3,876
    An observed and measureable reduction in drag for "sharkskin" seems pretty definitive to me! .........we are talking a bout the difference between a perfectly smooth surface and an uneven surface (albeit minimal)..............not the difference between matt and polished both of which can be equally smooth.

  7. #14
    Senior Member
    Join Date
    Nov 2009
    Posts
    3,876
    I think we may also be talking about grip ( fin) and early planing not just outright speed.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •