Transom drain flaps

[Graham T]

Having spent far too long trying to get the water out after a capsize I have decided that our transom drain holes need flaps. I had previously rejected these because I liked the look of the shiny varnished transom unencumbered with bits of plastic but like the non slip on the gunwhales which I had also previously rejected on aesthetic grounds I now think it may be faster not to sail with a boat full of water (or a trapeze crew flying around the forestay at every wave). What I want is some flexible clear plastic film so no hinges are required - you know the stuff. What I don't know is what to ask for or where to get it at a reasonable non marine price..... I'm sure one you can help.
Thanks
Graham

[JohnK]

If you're really going for cheap, circular holes and kitchen funnels. Worked on my old Ent many years ago.
JohnKn

[Graham T]

Holes much too large for funnels and anyway aesthetics do come into it... As invisible as possible please......

[jpa_wfsc]

You may want to try lexan film - a bit like perspex, but very flexible and tough so unlike perspex it is hard to shatter. It will be flexible enough not to require hinges, if the flap holes are quite large.

An example source is http://www.theplasticshop.co.uk/lexan-e ... 900-0.html

But - what boat is this? The only boat that I have ever really believed my transom flaps worked in was a Phantom - very low rocker aft, and very good acceleration meant that the water really did run out the back! In most boats their main use is to allow the hull to drain and breath well when parked in the dinghy yard. (In my opinion...). And to allow the water to run out as you clamber up the slipway. In the peggie they are just a nuisance as they are well to small to work when you need to clear a swamped boat, but irritatingly leaky - I wish they were not there (and that I had some lexan to close them off properly with). My Finn has transom holes (without flaps) but as she has a raised self draining floor they do work OK. The tunnel draining Matt's Skoll Moth works OK - again, the floor is in any case above water level (when he is sailing her). I can't imagine they would be much use in a fairy finn for example - what actually happens, Finnattics?

[Graham T]

The boat is an Osprey - when flooded the water level is to the top of the Transom. The holes do clear it when it gets moving (and it has the power to accelerate even full of water) but if you tack or slow down for any reason it all comes back in with no flaps to stop it.... Anyway thanks for the link - sounds like just what I wanted.

[Graham T]

But they only sell 8x4 sheets of the thin stuff... Anyone else need some too? At least I know what to look for now.

[Ed]

There is a real art to clearing water through transom flaps....

Some boats I have never seemed to be able to master it, others I have.

It took me years to work out how to use them in my MkIX Merlin, but after watching many capsized crews at a windy Merlin inlands and talking to a few people, I changed my technique and suddenly I could do it. A bit of wind helps though. I was once crewing an NSM4 when we filled it up with mud as we launched. Very unwisely we decided to half fill the boat to get some water in to clear out the mud. After we had done that we found that there simply was not enough wind to lift the boat enough to clear the water, leading to a very slow race indeed.

cheers

eib

[Nessa]

I have good sized transom flaps in the Aged P, but even so I still take a hefty bailer (disguised as a cut down 4pt milk bottle) along to help the water on its way.

I have a similar problem with her streaker. It is old style, ie no false floor, so if it goes over it comes up like a full bath tub. Even the self bailers can't cope. again the bailer has to come along for the ride. I am now contemplating drain holes contender style, but can't be sure they won't fill with water.

[Nigel]

when flooded the water level is to the top of the Transom

Is there any space for more buoyancy?. It sounds like a good idea unless your transom is very low and will also mean there is less water inside to shift

[PeterV]

I've expressed my opinion on transom flaps before. Get a big bucket and spend 2 minutes bailing out. Then open the bailers and carry on the race. You'll lose far less time than faffing around trying to get the water out the back through the flaps. I've always blocked them up on boats I've bought with them.

[ACB]

Which leads me to the Albacore After Deck Question:

The very definite opinion of serious Albacore sailors is that one should not have an after deck, on grounds of weight in the ends. On the other hand, I quite like the look of boats with after decks, and one could get a good big buoyancy tank in there, if one did without transom flaps, which would mean less places for water to get into in the first place. I'm tempted to put the after deck back and keep the water in the middle of the boat, as I have never had much luck with the "accelerate away and shoot it out of the back" technique.

[roger]

I think the Osprey should be ok with transom flaps. They certainly work well on the Hornet and lose loads of water before the bailers really kick in. The Osprey is much more powerful than the Hornet but I guess has a much larger volume of water to move. I am sure Ive seen Ossies with transom flaps.

As far as sourcing perspex I found the back of my dads shed is a great source of useful stuff. (Sorry theres no perspex left I used it for flaps on the Hornet.)

[Ancient Geek]

Thought I'd add my few ore or put my oar in!
In the early to mis 60's the Merlin Rocket class adopted transom flaps after some very dramatic trials. They worked and we soon discovered the trick was not be too gready and to start sailing away on a close reach with not a lot of power applied and to slowly increase the power (By pulling in the sails.) and as the boat rose ans water went back it ought to be and only then to bear away onto a beam and then broad reach to complete the process and hand over to the self bailers!
They work in any boat, even according an Oympic Finn sailor in a Finn.

[Graham T]

Yes - I wouldn't be without transom drain holes in the Osprey - they do work but on aesthetic grounds I have been sailing without flaps as I like the unencumbered varnish look. This is o.k. in high winds as they empty the boat in minutes but in lighter weather if you slow down at all the water just comes back in... I now have half a sheet of makrolon to play with so I will attempt a hingeless design safe in the knowledge I have plenty spare if the first attempt doesn't work (and it only cost £8.00)

I also have transom holes on my Miracle - much less use at getting the boat empty but invaluable as windows to show the kids (and some adults) the importance of boat trim. Having two little windows where you can see the turbulence in the wake as you move your bum back is an important visual teaching aid.

[Pat]

Our Merlin has one single piece of 1mm or 1.5mm plastic which covers both holes and is hinged by two screws in the centre between the rudder fittings. A small hole in the plastic in the centre of each transom hole has elastic knotted through it which goes to a hook by the toestrap fixing and holds the flap shut but stretches and opens when a weight of water pushes from inside the boat.
On the race Lark we've used the flexible plastic cut from the lids of trade size paint tubs - that's Sandy taking his work everywhere