Fitting Bilge Pump to Delphin 155

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Allan Olesen
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Re: Fitting Bilge Pump to Delphin 155

Post by Allan Olesen » Mon Sep 11, 2017 5:53 am

A new observation which may be a reason for abandoning the idea of a non return valve:

This weekend we trained scoop rescue. I was the last "victim" in row, so when I was rescued and my cockpit was almost completely water filled, I just strapped on my sprayskirt and started paddling with the group, letting the pump do its job. (A very satisfying feeling, by the way!)

While I was paddling, the vacuum in the cockpit became so high that the sprayskirt was sucked almost to the bottom of the kayak. Suddenly, I heard a quite forceful swooshing sound as air was sucked into the cockpit, and the sprayskirt returned to its normal position.

At first I did not realize where the incoming air had come from - I actually thought that the vacuum had been large enough to burst my sprayskirt somewhere - but then it occured to me that it was of course the pump which had stopped pumping and the air was being sucked backwards through the pump outlet.

If I had had a non return valve in my outlet hose, I would have had to vent my cockpit manually by releasing the sprayskirt.

Eventually, the pressure would of course have been slowly normalized through whatever leaks I have may have in the sealing between the sprayskirt and cockpit coaming / drysuit. But that could have taken a very long time, given that the slow pump was able to create the vacuum in the first place. (Again a very satisfying feeling, by the way: It seems that my Snapdragon sprayskirt works!)

seawolf856
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Re: Fitting Bilge Pump to Delphin 155

Post by seawolf856 » Wed Sep 13, 2017 1:32 pm

Haha, good point Allan. I was talking to a couple of old sea dogs on a beach on the Menai straights about my pump install. They both had pumps fitted and strangely enough, warned me about having to 'crack' the sprayskirt to avoid a vacuum in the cockpit. To be honest I found it a little difficult to believe that such a small pump would create a vacuum but when I thought about it, it is pretty obvious that the volume of water being removed from the cockpit is considerable and has to be replaced by air at some point or a vacuum will indeed be formed. Thanks for raising the point, I will hopefully remember to crack my sprayskirt as I paddle away with that satisfied smile on my face.

Phizz4
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Re: Fitting Bilge Pump to Delphin 155

Post by Phizz4 » Sat Oct 07, 2017 8:41 pm

I haven't read all of this thread so apologies if I am covering points already made. I have been using a Yuasa 1.2 amp hour gel battery but, as it sits inactive for quite long periods (due to a rubbish summer) it has come to the end of its life. I have replaced it with a set up from Mark at https://www.mtbbatteries.co.uk/ He happens to be local to me and I was able to collect but he does a pretty rapid mail order service. I got him to link three Panasonic 18650, 3400 mAh together in series to give a 12 volt output. The battery pack, plus a dedicated charger, cost £41. Much lighter than the gel battery, much longer run time and can withstand long periods of non-use so long as they are maintained at about 50% charge. I've now fixed my pump and switch in place with marine adhesive and soon I will pluck up the courage to drill the deck and sort an outlet for the hose like Douglas has done. For the moment my Reed spraydeck has the optional bale hole in it.

seawolf856
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Re: Fitting Bilge Pump to Delphin 155

Post by seawolf856 » Wed Oct 11, 2017 2:17 pm

Hi Phizz4, welcome to the biggest thread you are likely to see. That is for a very good reason. I would recommend you read this from top to bottom and also any associated threads on electric bilge pumps, you will discover a whole world of really helpful tips and advice. You will also discover that there is no one simple solution to fitting an electric bilge pump to a sea kayak.
With regards to batteries, my battery is the most expensive component of my system. I use a Lion 12v 10mAh unit from Tracer and it has been brilliant. I chose a Lion battery for the size and weight advantages. I know Lion batteries need a little bit of looking after but they are small and light and the 10mAh has emptied my boat dozens of times (training days) without having to be recharged. I can also use it to recharge my phone/GPS/head torch etc using a neat 12v accessory plug.

Good luck with the final part of your install. I've posted a couple of photos of my system, including the scary drilling the deck moment. Let us all know how you get on.

Spikeedog
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Re: Fitting Bilge Pump to Delphin 155

Post by Spikeedog » Tue Jul 10, 2018 11:04 am

So I'm just finishing the build of a Shrike Greenland style kayak and am planning to install an automatic pump. I've read the whole thread and other blogs etc. V.useful. Thanks. Is the Whale pump still the way to go (seems to have the lowest switch off level at 10mm)? And what's the latest on non return valves? Any experience would be very much appreciated. I wasn't able to open the photos in the thread which is annoying because it's easier to learn from other installations by seeing and comparing and working out how to adapt for your own kayak.
#seawolf856

seawolf856
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Re: Fitting Bilge Pump to Delphin 155

Post by seawolf856 » Thu Jul 12, 2018 12:57 am

Hi Spikeedog, my whale pump has now been tested many times in both real and practice situations - mainly practice ones I’m glad to say. It empties down to a level where you wouldn’t notice the water left in the boat. The auto switch on has never failed to operate, however I have had a few occasions where the pump seems reluctant to switch off. I think this has been due to the pump becoming air locked as the water level falls below the top of the intake nozzle and due to the movement of the boat in rough water, air gets into the intake and prevents the impeller from grabbing water. Don’t get me wrong, by this point the boat is almost empty but it is a little annoying when the pump continues to buzz on. This doesn’t seem to have harmed the pump in any way. As far as non return valves go, I fitted an “in line” one on a slight upward angle in the outlet hose and it has worked every time so far.
Good luck with your installation. My paddling buddy has also just fitted the vertical whale pump to his Delphin. He has a slightly different switching system to me but his installation went well and works brilliantly. He may come on and give you some more tips.

Allan Olesen
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Re: Fitting Bilge Pump to Delphin 155

Post by Allan Olesen » Thu Jul 12, 2018 9:12 am

Seawolf, have you tried if your switch problem will go away if you remove the non return valve?

The slight back pressure from the non return valve could be the reason for the air pocket you describe.

seawolf856
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Re: Fitting Bilge Pump to Delphin 155

Post by seawolf856 » Thu Jul 12, 2018 11:09 am

Hi Allan, thanks for the suggestion. Yes I have tried without the NRV but the airlock still occurs if I am in slightly rough conditions. I can understand exactly why the pump is running on in rough water and it actually does NOT happen in calm water when the auto sensor has enough time to detect that the cockpit is free of water. If there is enough water left in the boat to fully submerge the pump strainer, the anti airlock holes in the pump head are very effective and allow the pump to re-prime and it will shift water again. I am not really too bothered about the issue, my pump is quiet and in a proper 'live' scenario, the pump will have already done its job and emptied the boat so happy days. It is the application of an automatic bilge pump to a sea kayak which is the issue here, not the design of the auto sensor or pump itself. I can't be bothered to fit a manual switch as an override even though the wiring is in place.
I would like to leave the NRV out of the system but it is surprising how much water gets into the cockpit via the 19mm dia skin fitting and past the (static) pump impeller when paddling in swell.

Thanks again for your active involvement wit this thread, any other operational experience of automatic bilge pumps would be most welcome.

Spikeedog
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Re: Fitting Bilge Pump to Delphin 155

Post by Spikeedog » Thu Jul 12, 2018 2:18 pm

Excellent stuff guys. Thanks again. I think I would worry about a flat battery if I can't switch it off. How about an open skin fitting with a soft foam bung when you're on the water - would there be enough pressure for the 650 pump to squeeze it out? Still doesn't help with the pump not switching off though. A v.big sponge at the front of the cockpit?

Also, daft question - if you can perfect a reliable roll in rough seas (one day perhaps), how much water would you get in the cockpit?

Allan Olesen
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Re: Fitting Bilge Pump to Delphin 155

Post by Allan Olesen » Fri Jul 13, 2018 8:57 am

seawolf856 wrote:
Thu Jul 12, 2018 11:09 am
I would like to leave the NRV out of the system but it is surprising how much water gets into the cockpit via the 19mm dia skin fitting and past the (static) pump impeller when paddling in swell.
I had the same experience (also using an automatic pump, same model as suggested by Douglas Wilcox in this thread).

I solved it by making a plug from a syringe. A part of the syringe housing is permanently positioned in the skin fitting, and a part of the syringe piston is the plug. This gives me a nice seal with an O-ring. The plug is kept safe by a piece of string attached to the inside of the skin fitting.

When the plug is in place, everything sits flush with the deck, just with a small string loop coming out of the top of the plug so I have something to grab when I need to pull the plug. When I pull the plug, it dangles at the end of the string. This works really well.

Also, I have installed a larger skin fitting with the pump hose placed inside the skin fitting. So I have completely unrestricted water flow through the hose to the outside. The syringe housing sits in the skin fitting after the end of the hose, and it has slightly larger inside diameter than the hose, so this gives no restriction either.

Compared to my first solution where I used a skin fitting which could fit inside the hose, effectively only giving me a 12 mm opening to the outside, the water flow has increased with 50%, and I am no longer shooting a 60 cm high beam of water up in the air when the pump runs. (The latter made me unpopular when training partner rescues, and my rescuer had his head over the pump outlet while stabilizing my kayak.)

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Re: Fitting Bilge Pump to Delphin 155

Post by Allan Olesen » Fri Jul 13, 2018 9:22 am

Spikeedog wrote:
Thu Jul 12, 2018 2:18 pm
Excellent stuff guys. Thanks again. I think I would worry about a flat battery if I can't switch it off. How about an open skin fitting with a soft foam bung when you're on the water - would there be enough pressure for the 650 pump to squeeze it out? Still doesn't help with the pump not switching off though. A v.big sponge at the front of the cockpit?

Also, daft question - if you can perfect a reliable roll in rough seas (one day perhaps), how much water would you get in the cockpit?
I have never run my battery flat. I have a pretty large battery, 2300 or 2600 mAh, because I wanted to be able to charge my VHF from it. I have charged my VHF and used the pump on two long day trips during winter on one charge. Right now the battery is just sitting in my kayak in the club, and a few days ago I charged it for the first time during the last 6 months where I have used it occasionally. I don't know how discharged the battery was, but the charger switched off pretty quickly, so I think there was plenty of juice left.

Douglas Wilcox has reported somewhere in this thread that he doesn't even have a switch for turning the pump off, and he has a battery half the size of mine. With this solution, he can go on several day trips (was it 5?) on one charge. I suppose he disconnects the battery at night...

Regarding the roll:
I don't think that a roll brings that much water into the kayak through the pump discharge. After all, the duration of a roll is only a few seconds. In my case, the water comes in when I edge the kayak. I always edge my kayaks a lot when maneuvering, and this brings the outlet opening under the water line for a lot of time during a trip.

seawolf856
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Re: Fitting Bilge Pump to Delphin 155

Post by seawolf856 » Fri Jul 13, 2018 11:13 am

Once again Allan has it spot on. Edging the boat is when water is most likely to get in. Also next time you are paddling in swell or waves, look at the paddlers around you and you will see how much time their rear deck spends awash or even under the waterline.
I actually use a champagne cork (whittled down) to act as a plug. It is drilled out centrally with a nice bright piece of yellow Hi Viz deck line threaded through and tethered so I can see it, grab it and pull it out easily. It works really well and it is surprising how many comments I get asking why I've got a champagne cork plugging a hole in my boat!!
I decided to invest in a high tech (LiPo) battery. It is a 12v 10Ah and is very small and lightweight but cost £150. However even if my pump runs on for a while, my battery never needs charging. I have adaptors to allow me to charge my VHF, GPS and phone from it and I've still only had to charge the battery once or twice since I've had it. I would recommend investing in this type of battery - take look at www.tracerpower.com
I also love Allan's idea of using an oversize skin fitting and putting the hose inside it to give unrestricted flow. When I first assembled my pump system I was unpleasantly surprised to discover that a 19mm (3/4") skin fitting has an internal orifice diameter of only around 12mm which adds significant pressure drop (head) in the system and therefore lowers the pump flow rate.

Spikeedog
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Re: Fitting Bilge Pump to Delphin 155

Post by Spikeedog » Fri Jul 13, 2018 11:32 am

Both sets of comments absolutely on point and v.helpful. big thanks.

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Re: Fitting Bilge Pump to Delphin 155

Post by PlymouthDamo » Fri Jul 13, 2018 2:53 pm

Just a thought about putting a bilge pump in a Shrike. One of the things you're going to like most about it is that it's so light, so I'd definitely recommend you just get out and paddle the thing and enjoy the current good weather before you start thinking about putting a pump in.

Personally, if I decided I wanted an electric pump, I'd buy a cheap, heavy second-hand boat and put it in that. If the boat's already heavy, then a bilge pump doesn't make much difference as you're probably already going to be using a trolley or 2-person lifts. Whereas if you put a pump system in a Shrike, you're taking an extraordinarily lightweight boat and making it ordinary - just seems a shame. At least enjoy putting it on and off your roofrack a few times before you decide(!)

And unless you're planning to do anything heroic, the lack of an auto pump isn't as drastic as you might think. One of my Shrikes is a comically low profile rolling boat, to such an extent that onlookers occasionally point out that I'm sinking. Occasionally, I mess around with re-entry rolls and rolling without a spraydeck to completely fill the cockpit. It still won't sink, and I've been able to paddle it through roughish seas whilst swamped. I don't deny that a pump could save my life in the right conditions, but I try to avoid those conditions, and most people I paddle with do likewise.

Spikeedog
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Re: Fitting Bilge Pump to Delphin 155

Post by Spikeedog » Fri Jul 13, 2018 5:05 pm

Good point. I can lift it and I was going to give it a good try out first and maybe perfect a decent roll..... But how am I going to fill the winter? If I were to build another it would have to be in warm weather!

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Re: Fitting Bilge Pump to Delphin 155

Post by PlymouthDamo » Fri Jul 13, 2018 11:02 pm

There'll be plenty of things to fill your winter, e.g. making a few greenland sticks or weeping over and re-varnishing the first scratches on your precious new boat. I built two of my boats in winter, which worked out okay - the worst I had was a run of glass tape which just refused to fully wet out with epoxy on a particularly icy night and had to be peeled off amidst much swearing. But overall, I'd say building a boat was a brilliant way to preserve your sanity during the long dark months.

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Re: Fitting Bilge Pump to Delphin 155

Post by Spikeedog » Sat Jul 14, 2018 10:37 am

PlymouthDamo wrote:
Fri Jul 13, 2018 11:02 pm
There'll be plenty of things to fill your winter, e.g. making a few greenland sticks or weeping over and re-varnishing the first scratches on your precious new boat. I built two of my boats in winter, which worked out okay - the worst I had was a run of glass tape which just refused to fully wet out with epoxy on a particularly icy night and had to be peeled off amidst much swearing. But overall, I'd say building a boat was a brilliant way to preserve your sanity during the long dark months.
[/q

A Greenland paddle is a good shout. The epoxy just doesn't behave in cold conditions (N.E.Scotland) and I had to remove a whole coat coz it was cold and damp by the time I got it on and it was just soft and waxy all over in the end. This weather is great though it just glides on and finishes really smooth and hard. Thanks again.

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