Hobie Cat Forums

Seat Scupper DRAIN VALVE prototype

After spending a lot of time sailing and sitting in a puddle of water, I have decided to do something about it.

Have tried seat foam to lift me up out of the puddle but the solution is really a one way scupper plug to fit the screw in seat drain holes.

HERE IT IS

_________________
Geordie
West Ausie

My latest invention
I started with valves from a diving snorkel.


I have been looking high and low for a valve that starts out about the right size but alas it has been hard to track down. The initial idea was to make a round disc to insert on the end of the plug but I tried this idea first.

I tool out the silicone valves. Cut out the valve central holder bit and trimmed it to fit in the end of the scupper plug


Drilled out the scupper plug and cut out the excess plastic for a good drain hole lead in.


I fitted and glued my central valve mount with heaps of super glue (Sikaflex brand is amazingly strong).


I trimmed and sanded the end of the finished plug to get a flat seating surface for the valve flap.
Then I trimmed the valve to a smaller diameter with really sharp scissors.







AND Yes IT WORKS

_________________
Geordie
West Ausie

When do you start in mass production? I'll take 4!

Great craftsmanship effort to solve this issue. Bob

_________________
Bob
2013 Oasis w/ Sail
Virginia

And I'll take 2. Come on Geordie, you always wanted to retire and have a little earner on the side.

Mate, that is a good one. I suppose you wouldn't class the wet arse as a problem rather than an annoyance but the way you've solved it is very clever.

How well do they work ?

_________________


Don't take life too seriously................it ain't permanent.

Outstanding. My idea had been to use some sort of check ball inside the plug, but I haven't had the time to source exactly what I'd need.

Yours looks great. Hopefully it's the cure for the Island seat puddle.

What they said!
Great innovation there Geordie and well documented. Very clever.
At speed does the checkvalve open automatically with the force of the flowing water under the hull?

Please let us know when you go into production.

A top idea from down under! While I appreciate the effort involved in making these by hand, so "production" is but a dream, do you know a source for the supply of check valves?

Thanks guys I don't think that I will retire on this one, it took me half a day to make the prototype. It has been something that has been bugging me for a while. Not so much the wet bum but the fact that there is not a simple little valve available.

My two lines ofthought have been to use a flat valve like this, which I am most familliar with from my diving equipment servicing. Or as Tom suggested a ball type valve which would ned to be in a small tube.

For the flat valve, all it would need to make a retrofit, would be a little disc end to be fitted and glued onto the scupper plug.

Tony
The standard size valves from a snorkel are unfortunately just a little too big (available as a replacement at most dive shops). Hence I trimmed down the edges of this one to test.
I have however, just seen a snorkel that has a pair of much smaller diameter check valves which look about right (but I have not been able to pull one apart yet as another diver was using it at the time). They are made by an Australia company (probably in China) by Land and Sea Sports.

So far I have only been out for a morning paddle and I poored a bucket of water into the seat, Yes it did drain rwell, although slowly.
Thelower end of th evalve is sitting well up in the scupper so I don't think that waterflow will open it and push any water back up.
These sort of valves work really well for exhaust/drain valves on diving regulators and snorkels where they are subjet to some water movement (not that it is that fast, except when diving around reef when there are big waves overhead) they only have a little guard cover but not much to stop water movement over the valve.

_________________
Geordie
West Ausie

I think Stringy was thinking more of a possible Bernoulli effect, where the flow of water across the mouth of the valve might actually serve to suck water out of the seatwell. Roadrunner has, in the past, advocated sticking tape across part of the lower scupper hole, to achieve this effect.
viewtopic.php?f=69&t=36172
The valve may work well in association with tape, in that the tape will cause the seatwell to drain when the boat is in motion and the valve will stop it refilling when the boat slows down.

_________________

Chrisj,
yes good point.

The effect of suction from water flow past the scupper should help. I used to sail small yachts that had really simple scuppers that were a flat flap opening backwards and at speed sucked water out very effectively.

I might have to try the tape idea in association with the valve.

_________________
Geordie
West Ausie

Here are a few more valves I tried: Blue one in top photo.
the first was simply the end valve cut from a Tabata brand snorkel and glued to the top of a Hobie scupper plug (drilled out the plug first). This traps a little water as it sitts up in the scupper hole.


The most successful drain valve but also the most work to make and expensive:
For this I bought a large boat drain plug ($7.95) which I trimmed down and rounded the flange to fit into the top of the Hobie seat hole (the top photo shows the progression from boat plug trimmed down to a circle).
Silicone sealer did the trick to seal it in place above the original hole (photo below).

Then drilled out the drain bung and glued a snorkel drain valve into the end. This larger plug allowed me to use a larger valve (about 1 ") and this has much less resistance to open and drain water, hence it works best.

_________________
Geordie
West Ausie

What size is the TI scupper holes under the seats? SMALL/MEDIUM/OR LARGE?
After a lot of Google searching, I have found that valves come in small/medium/large. But not a single site states what the actual diameters are.
I think my TI scupper holes are about 3/4 inch maximum diameter.
Some manufacturers have charts for their kayak/valve combos...but still state that their model takes a medium or small, etc., but never list an actual measurement.
There are a considerable number of retail sites offering valves for sale but only listed as small/medium/large. Two mediums cost about $20.00. I don't want to waste money buying valves that don't fit.

Hi Tidalwave,
they are a screw in bung that is commonly used for a drain plug in a boat, but do not normally come with a one way valve. Which is why I have been experimenting with making my own.

I think that I saw another post that the Only one way valve that Ocean Kayaks make is to big. They list small, medium and large plugs. But these are plugs not drain valves.

If you can find anyone with a small size drain valve then ask them for dimensions

_________________
Geordie
West Ausie

I have found at least half a dozen retailers that sell not only plugs but also valves.
They come in very small/small/medium/large sizes. The valves have o-rings to help seat the valve into the scupper hole. They don't screw in like the Hobie plugs but you force the correct sized valve into the hole and the o-ring holds the valve in place. The valves use what looks like inverted silicon mushroom valve heads. One company even has a Youtube video to show how to install the valve and how it only drains out and seals when water tried to rise up the scupper hole.
They also come with a 'leash' so you can pull them out when needed.
Most of the valves are color coded green, yellow, red, or blue depended on their size.
They are exactly what I need but as I stated...nowhere are the actual diameters listed just small/.... etc.
That's why I was hoping that Matt knew what 'size' the seat scupper plugs are for the TI, medium/large?