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PostPosted: Tue Dec 31, 2013 7:27 am 
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Location: S.E. Florida
petersumm,

The issue with the siphon valve is that the flapper valve falls open. What needs to be done is keep the flapper closed while sitting still and submerged. The 8 mm polypropylene balls now will come into play.

This is my latest idea and it worked in a sink test. I had not yet attached the screen.

Cut the valve off at the the flexible hose intersection leaving the entire valve housing containing the flapper. Cut the valve housing off flush at the "T" intersection of the hand bubble throat . You now have a 3/4" long housing containing the flapper valve. There is a 1/2" deep cavity with a tapered opening now where the flexible hose was.
Insert three (3) 8 mm polypropylene balls into the cavity. 10 mm balls are too big even with just two (2). Cut and glue a plastic strainer mesh overlapping the opening with silicone adhesive.

I will insert this into the bottom of the hull with silicone as in the other posts.

When the valve is submerged the balls keep the flapper closed and there is enough room in the cavity for the balls to drop, allow the flap to open partially and allow drainage.

I will post pictures and report on the outcome.

Revo

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I would rather be kayaking and think about work than to be at work thinking about kayaking.
A Thrill Ride is being dragged around in your kayak for 40 minutes by an extremely large fish.


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PostPosted: Tue Dec 31, 2013 2:47 pm 
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These are the people who have responded:

http://www.complexplastics.com/globes/pricelist

I'll let you know if I find others.


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PostPosted: Tue Dec 31, 2013 3:16 pm 
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Here is the new self draining scupper.

Assembly time about 20 minutes per scupper.
Cost: (2) siphons from Home Depot for about $3.00 each + shipping. (1) bag of 8 mm polypropylene balls (50 count smallest I could get) at $3.00 + shipping. (1) stainless steel mesh kitchen strainer about $3.00 at Target. (1) tube silicone adhesive $3.97 at home depot.

siphon
Image

Cut at blue marks
Image

The flapper and housing
Image

cut mesh off strainer have the balls & glue ready
Image

Cut mesh to fit and insert the balls into the cavity (flapper side of valve)
Image

One housing held 3 balls and the other only would hold two balls. I may have cut it a little shorter at the hose or it was a manufacturing inconsistency. Two should work as well as 3.

apply bead of silicone glue around edge (careful not to get it inside)
Image

Press screen in place and add small amount of silicone on top
Image

Finished scupper drain
Image
Image

Apply a bead of silicone around the scupper and insert into underside of the seat drain scupper hole. Finish off filling around it with silicone.
Image
Image


Water test will be tomorrow once silicone has set overnight. The valves worked in the sink. The balls kept the flapper closed and opened and drained when when water was added above. There was no water returning past the closed valve.

Anxious to give it an open water trial.

Revo

_________________
I would rather be kayaking and think about work than to be at work thinking about kayaking.
A Thrill Ride is being dragged around in your kayak for 40 minutes by an extremely large fish.


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PostPosted: Tue Dec 31, 2013 10:22 pm 
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Are they hollow balls and, if so, where did you get them?


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PostPosted: Wed Jan 01, 2014 6:04 am 
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The balls are solid polypropylene. That is why I am using more than one, size limitation and added buoyancy.

Sadly rain today but will water test between showers.

Revo

_________________
I would rather be kayaking and think about work than to be at work thinking about kayaking.
A Thrill Ride is being dragged around in your kayak for 40 minutes by an extremely large fish.


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PostPosted: Wed Jan 01, 2014 11:13 am 
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Not perfect. It did stop the accumulating puddle but not completely. There was seepage and still a little puddle. On smooth waters keep plugs in and in rougher waters where you take water over the side often it will help how much you sit in. That all depends on how much your weight sets the seat below the waterline.

I noticed even if the scuppers drain seat there is still a small puddle left. The scuppers low point is higher than the lowest point of the seat. A perfect self draining scupper will not eliminate what remains lower than the scupper itself. The seat of the revolution is a bathtub with no drain.

Sorry Hobie lowering the seat in the newer hulls just created IMO a very unfavorable condition.
I hope a redesign is in the works. The seat needs to be higher and drain into the mirage well and scuppers. The seat needs to remain above the waterline at the weight capacity of the kayak and scuppers located at seat low point.

Revo

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I would rather be kayaking and think about work than to be at work thinking about kayaking.
A Thrill Ride is being dragged around in your kayak for 40 minutes by an extremely large fish.


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PostPosted: Wed Jan 01, 2014 1:43 pm 
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Revo, nice try and thanks for sharing your efforts. It's definitely a challenge.

If you just want to raise your seat and don't have any CG issues, here's a solution fusioneng incorporated that should work well:
viewtopic.php?f=11&t=48589&p=217264&hilit=#p217264

You can use most any scrap of dense foam to lift the seat. Here's one that I used with the inflatables where water tends to accumulate in the seat area -- a piece or two from one of those interlocking play pads (probably won't get you in trouble with your wife, just your kids :lol: :
Image

You could even cut channels in the bottom so water could have good access to your scuppers. 8)


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PostPosted: Wed Jan 01, 2014 2:49 pm 
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Hey roadrunner,

Yes a challenge it is. It looks more and more like lifting seat better answer.
I don't use the hobie seat so not concerned about covering peg holes.

Revo

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I would rather be kayaking and think about work than to be at work thinking about kayaking.
A Thrill Ride is being dragged around in your kayak for 40 minutes by an extremely large fish.


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PostPosted: Wed Jan 01, 2014 11:54 pm 
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Raising the seat certainly makes sense.

In Hobie's defense, sitting low in the water is more of an issue for some of us than for others :( and it's a great deal easier for those who need to to raise their seats than for others to lower them.

A purpose-designed seat-raising cushion wouldn't go astray though.


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PostPosted: Fri Jan 03, 2014 9:34 am 
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The problem with polypropylene is that it's too dense - it floats, but only just - and with a specific gravity of 0.95g/cm3, a 9.3mm diameter ball would have about 0.02g of buoyancy in fresh water. Is there another material that could be used to keep the valve flaps shut? Polystyrene and cork spring to mind. It doesn't need to spherical, in fact a section of a cork out of a bottle might be ideal.


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PostPosted: Fri Jan 03, 2014 10:03 am 
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HMMMMMMM

now that is a thought petersumm

I happen to have a ton of wine corks. They may even be the right diameter to cut a slice and let it rise and fall in the cavity. I will take the new scuppers out of the kayak and give that a try. A cork disk just might do it. I was thinking about a light gauge wire hinge spring coiled around a post under the flapper.

The cork definitely is worth a try. You could use a slice almost 1/4" thick.

Still the seat does not drain 100% unless you lean to the side. The low point of the scuppers still allows about 3/8" to 1/2" of water to remain in the seat.

I have ordered an 18" x 18" x 1-1/4" thick waterproof closed cell foam square. I will channel the bottom to the scuppers. My seat does not use the seat peg holes so I can cover them up. I may look into scuplting it to shape with a foam cutter if needed.
http://www.ebay.com/itm/18-x-18-x-1-1-4 ... 1190873524


I will try the cork idea this weekend.

Revo

_________________
I would rather be kayaking and think about work than to be at work thinking about kayaking.
A Thrill Ride is being dragged around in your kayak for 40 minutes by an extremely large fish.


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PostPosted: Fri Jan 03, 2014 11:08 am 
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Location: Sarasota,Key West FL
Hey there might be something to that wine cork idea.....
If you were to cut the retainer rack arrangement off the bottom of the scupper screw plugs, so they are just screw in plugs, then take a wine cork and put about a 45 degree angle point on one end of the cork. Then just drop the cork into the underside of the scupper opening (from under the boat), maybe jam in a piece carbon rod or a screen into the hole at the bottom so the cork can't fall out the bottom. You might have to reach in the bottom and chamfer the bottom of the opening (at the base of the threads inside) to make sure the chamfered end of the cork makes a good seal when it is floating.
The cork would be just floating around inside the tube (plenty of space for water to get around it when draining). The cork would have enough flotation to rise up and block the opening when the seat is underwater, preventing water from coming in from underneath. As the cork bobb's around in waves it should loose it's seal enough to keep the seat draining, but have enough floatation to keep the opening sealed when you are sitting still and the seat is below the waterline.
I think the trick would be getting just the right amount of flotation on the cork to get the best of both worlds (adjusting the length of the cork), the ability to seal, yet still be able to bobb about when underway to allow draining.

Very simple to do, If someone needs a wine cork, feel free to send me a bottle of wine, I will drink it then send you the cork when done (my civic duty LOL).

Actually I think I'll remove my scupper screw in plugs (just take them out alltogether to try it out), and stuff wine corks in the tubes and block them in somehow just to try the idea out, just might work. I'll start with a whole wine cork with a pointed end. I'll try both natural cork and the plastic imitation cork stuff.

Bob


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PostPosted: Mon Jan 13, 2014 4:53 am 
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Some more maths that may be relevant, and because I have too much time on my hands:

Length of the AI = 4.88m (from the brochure)
Width of the AI = 0.70m (from the brochure for the Adventure)
Area displaced if approximated by a diamond shape = 4.88 * 0.70 / 2 = 1.71 sq m
Area displaced if approximated by a rectangle with a triangle at either end, each a third of the length = 4.88 * 0.7 * 2 /3 = 2.28 sq m
Average of the two is approximately two square metres, so let's use that as the area of the boat in the water because it makes the maths simple.

Weight of an empty AI = 39 kg (from the brochure)
Weight of water displaced by an empty AI = 39kg (Archimedes)
Volume of fresh water (1.00 kg/l) displaced by an empty AI = 39 litres = 0.039 cubic metres

Average depth of an empty AI = 0.039 / 2 = 0.0195 metres = 1.95cm

Extra volume of water displaced by a 93kg rider (me) = 93 litres = 0.093 cubic metres
Extra depth from 93kg rider = 0.093 / 2 = 0.0465 m = 4.65 cm

Total depth of AI and rider = 4.65 + 1.95 = 6.6cm (in fresh water)

Extra depth for every extra 10kg (eg akas & amas approx) = 0.5cm

Density of sea water 1.025 kg/l (from wikipedia)
Weight of sea water displaced by 39+93kg AI and rider = 132kg
Volume of sea water displaced by 39+93kg AI and rider = 132 / 1.025 = 128.8 litres

Average depth of AI and rider in salt water = 128.2 / 2 = 0.644 cm

Reduction in depth due to salt water = 0.166 cm = 1.66 mm

Interesting conclusions (if you're interested in that sort of thing):

Each 10kg of extra weight in the AI presses it about 0.5 cm further into the water (or 22 lb for 13/64" for our friends in the US, Liberia and Myanmar).

Salt water raises the boat by a little under 2mm (5/64").


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PostPosted: Tue Jan 14, 2014 5:00 am 
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After a bit more experimentation...

With the bungs out, level on dry land, I can collect a 2mm deep puddle of water in the seat of the AI. This I do consider a design flaw, but it could be rectified by collecting a 2mm deep puddle of some suitable liquid plastic in the bottom of the seat and letting it set. Any suggestions of what would work?

Failing that, a cushion under the seat would raise it enough.

With no akas & amas, I think my seat is about 7mm above water when sitting still in flat, fresh water. When I start moving though, or in choppy water, water may well splash up the empty bung holes and collect under the seat, which then soaks up the water.

With the rest of the sailing gear, I'm probably just above water level, but then you've probably little prospect of keeping dry anyway.

My thought is, when kayaking, put the bungs in, and when sailing, leave them out and possibly raise the seat slighly (particularly if you're on the heavy side).

Comments?


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PostPosted: Tue Jan 14, 2014 8:01 am 
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Location: High Point, NC
I had intended to make some sort of one-way scupper plugs but after more thought just decided to raise the bottom of the seat tub. It has worked perfectly. Water only comes in from the topside, and quickly runs right back out. None comes in from the scuppers in normal operation. And, it's been foolproof.

The only noticeable difference I can tell is that I have to duck my head just a bit more when taking or gybing to get my head under the sail. I'm fine with the trade off.

I'm sure I've posted this before, but in case those looking for an alternative here haven't seen it:

http://www.youtube.com/watch?v=rrdT0gzQPww


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