Blaxell Surfrider - Floor problems

Discussion in 'Boat Design' started by Surfrider, Jul 21, 2014.

  1. Surfrider
    Joined: Jul 2014
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    Surfrider Junior Member

    Hello Everyone,

    I have bought a Blaxell Surfrider 20ft boat, I knew I had to do some work to it and don’t mind at all. My questions relates to the following: I removed the floor and noticed there are no wooden stringers and bulkheads, instead these fibreglass rib type stringers and bulkheads. Starboard side ribs have detached from the hull and also have some cracks from people screwing in seats. When I lay in the new fibreglass to the ribs to attach it to the hull, should the boat be on a trailer….. or off the trailer??. I’m concerned about the deflection in the hull and pressure from the rollers underneath.
    I'm seriously thinking of cutting all the ribs out as I doubt I will be able to get a strong bond if I just re-resin/matt them back to the hull. Any body done this before?

    I would also like to install an inboard fuel tank in one of the old fish hutches…. Any help or recommendations would be greatly appreciated.
    Ally, Stainless or plastic. I have an outboard 100hp motor.

    Rgds

    Tuna
    :idea:
     
  2. Surfrider
    Joined: Jul 2014
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    Surfrider Junior Member

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  3. Mr Efficiency
    Joined: Oct 2010
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    Mr Efficiency Senior Member

    I would not be tearing them out, you are lucky there isn't a mess of rotten wood in there. When you say detached, what sort of gap is there ? Is the stringer set-up just one moulding ? Looking at that box channel, I would say it would not have gone out of shape. There may be a way of gettin it all fitting closely again, and using epoxy to lock it in to position. Re the fuel tank, people who should know tell me plastic is the way to go, if you can get the size/shape you need.
     
  4. Surfrider
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    Surfrider Junior Member

    Hi, Thanks for the reply:
    There is no 'GAP' between the braces and the hull. its is just detached. If you walk on the braced floor you can see the stringers moving, especially on the starboard side: look at this close up. photo 4[1].JPG
     
  5. Mr Efficiency
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    Mr Efficiency Senior Member

    Should be pretty well in shape then. You need to clean up the surfaces and re-glass it to the hull. Maybe epoxy rather than polyester.
     
  6. Surfrider
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    Surfrider Junior Member

    yes, but my question is.... do I do this with the boat on the trailer? or not on the trailer ie stands.
     
  7. Mr Efficiency
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    Mr Efficiency Senior Member

    If the separation of the internal frame from the hull skin is minimal, leave it on the trailer. I'd only be concerned about trueing it up if there was a sizeable gap. If your boat goes out of whack by 1/8" it will not matter at your boat's speeds.
     
  8. SamSam
    Joined: Feb 2005
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    SamSam Senior Member

    If what you're talking about are the dark lines in the foreground....

    When on the boat looking forward, starboard is on the right, port is on the left.

    Your structural grid is made separate from the hull, lowered in and then attached to the hull. It is either glued to the hull or it is "tabbed" in, which is narrow strips of fiberglass that run partway up the sides of the grid and then onto the hull. It looks like your tabbing has detached from the hull.

    http://www.yachtsurvey.com/Grids.htm

    This is tabbing...

    [​IMG]

    http://www.boatdesign.net/forums/fi...uilding/how-much-tabbing-stringers-50123.html

    You can't re-glue the tabbing as it is probably dirty and oily underneath, so you have to cut any loose tabbing off in the corner junction where the vertical sides of the grid meet the hull. You can grind it or carefully cut off with an abrasive cut off wheel (being mindful to gouge the hull as little as possible) or sharp chisel it, etc.

    Once the loose stuff is gone the hull and sides of the grid have to be lightly ground and cleaned to be receptive to new tabbing and resin.

    As far as supporting the hull. The grid doesn't have to touch the hull, in fact it probably shouldn't, and there will be various sized gaps. The place to see if the hull is out of shape is from the outside. If you see the rollers are deflecting the hull, or any light reflections look like there is deflection, you need to remedy it. We used to set new hulls on 3 barrels, 2 on the the back corners of the transom and one under the keel towards the bow.

    If you don't have any deflections from outside, like the trailer rollers, that is one thing. On a small flimsy hull like yours, you also have to watch for deflections from the inside, such as from your body weight. Sometimes you have to rig up support or reach way in so you can laminate without being in/on the hull itself.

    If you rip out that whole grid and try to start over, you'll have major problems.
     
  9. Mr Efficiency
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    Mr Efficiency Senior Member

    Grinding or cutting the old tabbing will be difficult without cutting onto the hull, if there is a tiny gap where the tabbing has separated, you could try slipping some sheet metal in there temporarily to protect it while you cut the old tabbing. Glass laminate is a lot softer than metal. Alternatively, thoroughly clean and sand the existing tabbing and hull adjacent to it, and just glass over the break with glass cloth and epoxy.
     
  10. SamSam
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    SamSam Senior Member

    That's a good idea to slide some sheet metal under, if possible. I'm seeing in the photo in post #4 that the tabbing has lifted free of the hull, so that would have to be removed.
     

  11. Rustle rose
    Joined: Feb 2015
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    Rustle rose New Member

    Surfrider, I'm wa based and I am considering similar works to you as there is evidence of hull flex and creaking floor.

    I also have an outboard and have noticed some minor flex and think the transom needs some reinforcement.

    I'm wondering how you got on with your floor repairs and whether we could share notes?
     
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