Transom Flaps

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neil
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Transom Flaps

Post by neil » Tue Mar 25, 2008 9:52 pm

The Raudaschl Finn as a couple of holes in the transom and there is evidence of the boat having transom flaps to cover the holes.

So.....do I use thin perspex with one side screwed down and hope it bends when needed - and if so how thick should the perspex be? Or do I use perspex and a hinge - if so, what type of hinge should I use, and more importantly where can they be sourced?

thanks

Neil
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Re: Transom Flaps

Post by Rupert » Tue Mar 25, 2008 9:56 pm

Duck tape and milk carton plastic...
Rupert

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neil
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Re: Transom Flaps

Post by neil » Tue Mar 25, 2008 10:46 pm

Skimmed or semi-skimmed? or as its a Finn I suppose full fat would be more appropriate.
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Ed
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Re: Transom Flaps

Post by Ed » Wed Mar 26, 2008 12:26 am

So many ways.....and yet so few of them seem to consistently work.

I think my favourite way is to use bungy cord through holes holding the perspex down on one side. The bungy cord is just firm enough to hold in place but water slopping around inside pushes past resistance of bungy cord.

It is held in place by another bungy cord through middle of perspex.

I sincerely doubt that makes any sense, but it is late and I have to be up early ....so that will have to do for now.

cheers

eib
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Re: Transom Flaps

Post by roger » Wed Mar 26, 2008 9:20 am

I have found that thin perspex secured on one side works very well the water pressure is enough to empty the Hornet rapidly. They are secure with bungee to keep them closed.
If they are round holes you could always use the old system of a couple of funnels held in place with bungee.
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Re: Transom Flaps

Post by STEVEB » Wed Mar 26, 2008 9:28 am

Hi,
I may be able to help you out with hinges, let me know dimensions if you are interested
Steve
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Re: Transom Flaps

Post by Garry R » Wed Mar 26, 2008 9:31 am

I have a couple of old transom flaps which were in a box of bits from an old merlin. They are pretty scratched, thick and hinged and I'm not sure what state they are in but you are welcome to them. The hinges may be ok - I'll look tonight.

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Re: Transom Flaps

Post by PeterV » Wed Mar 26, 2008 10:03 am

Neil,
I think you need to be aware that transom flaps in your Finn will almost certainly be a waste of time, however you arrange them. My experience of older Finns with little buoyancy is that there's only one way to carry on after a capsize, and that's to empty the majority of the water out with a big bucket then use the self bailers to empty the rest. If you rely on bailers and transon flaps you'll be sailing about for about 15 minutes before you're back up to speed, the bucket approach only takes about 2 minutes. Therefore on my Tiptree I screwed perspex over the transom holes having given up on funnels, flaps and other arrangements. I didn't have flaps in my first Fairey and the ones in Django have been refilled with wood.
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Re: Transom Flaps

Post by Brookesy » Wed Mar 26, 2008 11:07 am

Neil,
The flaps which were on that boat were heavy perpex with webbing as hinges, and not pretty. I would agree with Peter to a certain extent, and say carry a collapsible canvas bucket and rely on that and your four self bailers.
Filling the the round holes in the transom will be a pain and will again not look pretty as you will always see it as a mismatch. Why not use light weight funnels on bungy which you could still operate if you felt the need, plus you are not adding holes etc for hinges. Or just fablon them over, which is lighter and can be kicked or poked out if the need arises.
My old Raudaschl had the funnels and I found them fine if only when rinsing the boat out, and I seem to remember that they never let water back in when I launched.
In practice after a nasty capsize which scooped up lots, the bailers coped better, as by the time the level goes down as you try to sail it out, you will be nose down anyway, oh the pleasures of a Finn !!!
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Re: Transom Flaps

Post by Pat » Wed Mar 26, 2008 2:35 pm

We've tried paint tub lids with elastic hinges but the best flaps were those on the fat Merlin which we nicked for Half Cut. It's one piece of thin perspex (1.5 mil I believe) which goes right across both transom holes and has a couple of screws holding it on the centre line and making it self hinging. Add elastic to keep shut.
Am currently looking for a supply to repeat the technique.

Garry R

Re: Transom Flaps

Post by Garry R » Wed Mar 26, 2008 3:13 pm

http://cgi.ebay.co.uk/Sheet-of-2mm-thic ... dZViewItem

I know this is 2mm but it might work. I am surprised that 1.5mm perspex has the flexibility not crack when bent. I looked up 1.5mm perspex but it is seemingly sold in large sheets. Hope this helps

Garry R

Re: Transom Flaps

Post by Garry R » Wed Mar 26, 2008 3:18 pm


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Brookesy
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Re: Transom Flaps

Post by Brookesy » Wed Mar 26, 2008 4:26 pm

Neil,
If you want to go the flat route, I have 1.5mm lexan which can be cut to a circular size larger than the aperture, then cut off square at the top and taped with a piece of mylar sail tape directly to the transom so that gravity keeps it shut , bungy can be added if the tape is not stiff enough.
I bought the sheet from Plastexe in Exeter am am not using it on the FD as the transon is to stay open.
Graham.
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Re: Transom Flaps

Post by Rupert » Wed Mar 26, 2008 8:05 pm

Brookesy wrote:Neil,
If you want to go the flat route, I have 1.5mm lexan which can be cut to a circular size larger than the aperture, then cut off square at the top and taped with a piece of mylar sail tape directly to the transom so that gravity keeps it shut , bungy can be added if the tape is not stiff enough.
I bought the sheet from Plastexe in Exeter am am not using it on the FD as the transon is to stay open.
Graham.
This sounds like a posh version of my solution...
Rupert

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Re: Transom Flaps

Post by jpa_wfsc » Thu Mar 27, 2008 10:16 am

Pat wrote:We've tried paint tub lids with elastic hinges but the best flaps were those on the fat Merlin which we nicked for Half Cut. It's one piece of thin perspex (1.5 mil I believe) which goes right across both transom holes and has a couple of screws holding it on the centre line and making it self hinging. Add elastic to keep shut.
Am currently looking for a supply to repeat the technique.
B&Q have (had?) 2mm perspex sheet in relatively handy sheets of 2*4 foot. But I found it was way too brittle for the self-flapping version of transom flaps - you need to use hinges. (It is sold for picture framing). Lexan sheet, I have used at work and is both tough and flexible - 1mm lexan is sold on a roll - but I have never found it available in DIY sheets. . .

What material do RS and Laser use for those white self-flapping flaps on various self-draining boats (to stop them filling when you walk to the back to find out why, yet again, the rudder has floated up?)
j./

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