Latest News: Forums Technical Transom Flaps

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  • #4248

    Are the transom flaps on a World supposed to lie flat against the transom? As I hope you can see from attached photo, on my boat they curl outwards. This makes it very easy for water to come aboard and it seems like they aren’t really doing anything at all to impede it. I would image that the size of wave that would force them to close would be big enough to come right over the top.
    I’m thinking about taking them off, turning them around, and putting them back on so that they want to close up firmly. This would mean that the boat drains a little less freely, but should also take in water less easily.
    Any thoughts before I go ahead?

    #9776
    Colin Parkstone
    Participant

    Are they held closed with elastic cord from the centre of the flap to a hook in the boat and back to the other flap??? If not, how do you think they should??
    CP

    #9777

    Ah there’s definately no cord/bungee, but nor do I think there ever has been such- no hole to tie it to. So I presume that they are supposed to close quite firmly? Are you supposed to undo the cord to let the boat drain, or would the weight of water do that by itself?

    #9780

    The transom flaps on my World are just flimsy plastic, as yours look like. If you have self-bailers than the transom flaps are almost redundant and most cruisers tape them shut to the transom (I do) and only push them open in extreme circumstances; this prevents unwanted water ingress and you can easily punch them open if required. The self-bailers will empty water in most conditions fast enough.

    #9790

    Adrian,
    when you say ‘tape’ them shut, what sort of tape have you found to work best? My boat lives on a mooring so is fairly exposed. I suppose I could use sikaflex instead but they woudl then be hard to open.
    One of the reasons I moved to a World from my old MkI was that I thought that being self-draining would be a distinct advantage, so I am a little reluctant to tape up the flaps. But the amount of water that that pour in when I stand at the stern is not acceptable. Ideally I’d like the flaps to act more like valves, not letting water flow in but still allowing it to go out. Is this too much to ask?
    Another problem is that the boat tends to develop a list after heavy rain- probably free surface effect from rainwater gathered on the raised floor. I can’t see any way round this and it looks very odd, but I assume it is normal.

    #9796

    I have just used electrical tape in the past. I think I now use a clear repair tape (as I have it). Thus if I need to open the flaps I can just push them open from the inside. Just one strip of tape around the edge is enough to avoid water coming in when the transom is under water. This keeps my boat dry, even when camping afloat. I would guard against using sikaflex – tape is sufficient and very easy to remove when required in extremis.

    For general self draining when sailing I have the self-bailers under the thwart, which are easily up to the job even after a capsize and easier to use when under way. Beyond that getting your flaps to work as a valve sounds like an expensive challenge – and perhaps not necessary.

    I do not keep my boat afloat so cannot comment on what happens with water coming down the mast etc and why you get a list, other than if there is a slight list (which may not be very noticeable) at the start then water will settle that way, equally if your cover has a hole on one side this may make a difference. I am afraid I cannot offer much more advice here.

    #9798

    Thanks for that Adrian
    my boat lives on a mooring, without a cover. This is how all the local Wayfarers are kept- fending for themselves! So quite a bit of rainwater finds its way aboard. I switched from a MkI to a World in the hope that this would be the end of my bailing duties!
    I think I’ll go ahead with my idea of turning the flaps around, so that they will tend to press closed, rather than spring open.

    #9799
    Colin Parkstone
    Participant

    How about changing to a set of perspex flaps,more solid, and put on a light elastic cord to them to hold it shut.
    The elastic cord to them to be not so heavy as to allow the water to flow out ?

    Or use perspex flaps again but weight it on the outside so as to again close them against the sea water but inside water can get out?

    A point that struck me was that the flaps are a long way from the water and I wonder if the inside water was needing to be large to reach the flaps and flow out.

    If thats the case, maybe the water is not getting to the flaps but choosing a side of the boat to flow to and gathering that side. Slight list then is exaggerated with more water?????

    CP

    #9801

    Perspex flaps sounds robust, but how would I make the ‘hinge’? A strip of something flexible I suppose.
    In the photo, the flaps are indeed a long way above the water, but that’s just how the boat sits when unladen. With two people aboard they are closer to the water- and when moving fast enough to produce a decent wake water will actually come aboard unless you remember to move crew weight forward. I find the ability to see exactly what the water level is doing at the stern is very handy when trimming the boat at different speeds and points of sail!

    Certainly it would make sense that, whilst moored, the boat will always take on a list with the water pooled to one side or other. But I wonder if at some point it would reach an equilibrium where any additional water would flow out through the transom scuppers. So far I haven’t let that much water build up inside the boat.

    Does anybody on the forum keep a World on a mooring?

    #9803
    Bob Harland
    Participant

    We had one of the early Worlds – the transom flaps were perspex with a “hinge” of bungee – i.e. two pairs of holes drilled through the perspex and the transom on each flap. I guess a little crude. Closure was as Colin describes – another piece of bungee from a mid point on the flap to a hook in the boat.
    Initially we fitted some foam to give a better seal between the flap and transom. To some extent this was ok. But after a few seasons we taped them up.

    Water in the boat from rainfall should go out of the bailers – it should never get to the level of the transom flaps.
    I am slightly surprised at the list problem – but have never kept the boat on a mooring. If you have not checked, them do make sure there is no water getting into the buoyancy compartments. A common problem was through the screw-holes fixing the keelband. If you don’t have a drain hole in the transom then that is worth fitting.
    If the boat is on mimimum weight then that is the best chance for the bailers to work to maximum.
    hope that helps

    #9812

    I took the boat out of the water yesterday and, yes, there was a fair bit of water inside the buoyancy compartment. So that definately helps to explain the listing problem. I wonder where the leak is…

    Are you saying that boat ought to sit high enough in the water that the self-bailer can be left open when unattended? I suppose I’ll find out when I go back in the water.

    #9813
    admin
    Member

    The leak is probably mid point port side just below that yellow water-line stripe, there’s a repair there…

    My Enterprise has 3 or 4mm thick perspex transom flaps which are fixed to the boat using plastic piano hinges which seem to have a stainless steel hinge pin (it has not rusted. The flaps are held closed by a light bungy cord that is looped over a hook specific for the purpose about 300mm forward of the transom. When I kneel in the sternsheets to fit the rudder a trickle of water comes in but nothing serious. When completely swamped after a capsize recovery, the weight of water surging against the transom once I get sailing again overcomes the bungy cord and the flaps are pushed open. The system works really well and I am thinking about making ducts to allow me to fit flaps on my MK2.

    #9814
    matoi
    Member

    ND,
    I’ve experimented with the flaps on my World extensively (probably reported about it on the forum some time ago), and have just like you, experienced a bit of list after heavy rain when flaps and bailers were closed.
    I’m afraid the only good solution is
    a) find a way to keep your boat on land when left unattended for periods longer than a couple of days, or in bad weather
    b) seal permanently transom openings and rely on good bailers only, for better life when sailing and cruising
    If you are really interested, I could make a sketch of my ver4 flaps and how they were hinged (these were completely waterproof when closed, but still easily put into [their useless] function). But that would take a bit of time, and in the end, it still all comes to a) and b).
    All the best,
    Mato

    #9815
    Bob Harland
    Participant

    @No Disgrace wrote:

    I took the boat out of the water yesterday and, yes, there was a fair bit of water inside the buoyancy compartment. So that definitely helps to explain the listing problem. I wonder where the leak is…

    Are you saying that boat ought to sit high enough in the water that the self-bailer can be left open when unattended? I suppose I’ll find out when I go back in the water.

    Common source of leaks is the screwholes fixing the keelbands, less common around the bailers. If it is the screwholes then you will probably see water seeping out from them.
    Yes – you should be able to leave the bailers open when the boat is unattended.

    #9817
    Swiebertje
    Participant

    @Mike Summers wrote:

    The system works really well and I am thinking about making ducts to allow me to fit flaps on my MK2.

    That won’t fly. A MK2 does not have a double bottom. Hence the water level inside the cockpit is below the level of transom flaps. But if the water is above the floorboards, I hear you say. Then the flaps are submerged due to the weight of the water in the cockpit.

    The best bailer for a MK2 (and any other type): A scared men with a bucket.

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