Kayak Livewell & Dry Box (Part 2)

In part 1 I covered the basic construction of my dual purpose kayak dry box/livewell.

The were certain features that I wished to have with regards to the livewell, these were as follows:

  • Dual water level to cater to different sized bait
  • Internal aerator pump to minimise noise
  • Dual pump speed
  • Easy pump priming when afloat
  • On/off switch to be easily reachable
  • Quiet overboard draining
  • Alternative power source if required
  • External battery charging point
  • Ability to drain the tank when afloat

That potentially seemed a tall order, some may argue that it’s over-complicated, though it covered my potential needs. Plus it’s what I wanted, I like a challenge. It was potentially going to be challenging, and as it turned out, at times it was just that… and more!.

The basic design has already been covered, though here’s some additional photos that also show the later plastic blanking caps, on/off switch and external charging point.

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On the lower front edge is a drain plug. This allows the livewell to be drained when afloat if required (roughly 2 litres of water will remain) or to be drained when ashore prior to lifting the livewell off the kayak.

The switch was originally going to be positioned on the top of the battery box, though after sitting on the yak I decided it was too much of a stretch. Having it on the forward edge seemed like a good idea, though I had visions of it being accidentally knocked on and off, plus it’d be potentially rather messy routing wiring towards the front. In the end I positioned in on upper rear edge, comfortably within reach.

The switch itself is a three position ON/OFF/ON item, fitted with a waterproof rubber cover. The idea of this three position switch was to allow the unit to have two selectable speeds as well as an off position.

The question was how best to achieve a useable two speed setup. Ideally I wanted full power 12 volt operation for filling the tank quickly, stirring the tank, or just whenever I felt the need. I also wanted a lower second speed for general use and to maximise battery life. The issue was more with the lower speed and what speed did I really need??.

I decided to incorporate and speed regulator circuit, thus allowing me to have the choice on what my lower speed would be.

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As the speed regulator wasn’t a waterproof unit it had to located in the watertight battery box. Despite a few headaches this was eventually achieved. The main problem was with the circuit wiring, though it all came good in the end. It probably isn’t advisable to change this variable setting once afloat due to the location of the controller, though setting it mid-way will see the pump operating in the 6-8V region.

The photo below shows the wiring loom taking shape.

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The cut out allows fitment of a either a 12v/7Ah or 6v/12Ah SLA battery. The pump operation can be switched between 12v (Max) and a variable speed (Var) via the three position switch.

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I already have a 12V/12Ah fitted to the front of the kayak which powers my GPS, fish finder and stern light. As I expect the majority of the live baiting to take place during daylight hours it seems a shame not to use the existing battery, which would also minimise the all up weight.

To this end I fitted a two pin marine connector to the side of the battery box. This has two main functions, it allows connection of the same charging adapter that I currently use for charging my main kayak battery. The allows me to charge the livewell battery in situ should i feel the need using my existing charging setup.

The second function allows me to connect a jumper lead to the rear light socket which is powered from the main kayak battery. This allows me to operate the livewell without actually having to fit the livewell battery. I could even fit the livewell battery and the jumper lead which would prove a huge amount of battery life, though I cant ever imagine the need to do so.

The photo below show the close proximity of the battery box connection point to the rear light socket. I’ve already proved the principle and I’m currently making a waterproof lead, sadly it’s not quite fully ready at this moment in time.

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Next I’ll cover the plumbing, now this did also cause some stressful moments!. My initial plan was to have a short length of hose from the pump directly to the tankwell scupper with a non-return valve located within the scupper hole. I knew the pump would require priming and I’d measured that the amount with the pipe work and the pump was approximately 100ml.

I’d originally planned to use a large syringe with a short piece of flexible pipe on the end to inject water into the pump outlet thus backfilling the system. Let’s just say it didn’t work, basically it was badly airlocked due to the non-return valve and that plan was well and truly dead in the water!.

This totally messed up my plans, though with the container already drilled and the pump position low down I was kind of stuck. I decided to use a hand primer, similar to what you’ll find on outboard engines. I rigged this up which ultimately resulted in a large u-bend as the pipe returned to the pump. The hand pump is design for 3/8” pipe yet i was using 3/4” pipe. The pump itself could not move enough water to effectively remove the airlocks within the pipes, basically I was screwed.

Then at 2am (yes I was in the garage scratching my head at that stupid hour) I had a Eureka moment. The hand pump has an internal upper and lower non-return valve fitted internally. Being 3/8” they are also very restrictive on the water flow. I removed the valves and fitted a 3/4” non-return valve to the bottom the the hand pump. However, I positioned the upper (now 3/4”) non-return valve not to the top of the hand pump, but 1/2 way along the pipe between the top of the hand pump and the aerator intake.

In the photo below the hand primer and two non-return valves are visible.

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This basically changed everything and allowed the small hand pump to easily push the airlocks through the 3/4” pipe work. The non-return valves also prevent draining of the tank when the aerator pump is switched off. The large diameter of the non-return valves also allows full flow of water through the pipes.

I also made two overflow pipes, one for the higher and one for the low level overflows. You can fit the pipe to suit the level you want and leave the other blanked. The other option is the fit both pipes and to use a 1” bung to block the outlet you don’t want from within the container. This allows you the option of changing the water level when afloat in seconds.

The photo below shows the two overflow pipes and well as the pump feed pipe incorporating the hand primer.

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Here’s the pump pipe fitted. All pipes are fitted in seconds.

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The overflows were covered with plastic mesh on the outside face to prevent smaller bait such as sandeels escaping from the tank. The reason it was placed on the outer face was to enable the fitment of a rubber bung within the tank as previously mentioned.

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The inlet to the lower non-return valve in the pump feed pipe was also fitted with a mesh cover to prevent coarse debris being sucked into the valves and ultimately the pump. There is even mesh on the pump outlet to prevent small fish from entering the pump when it’s switched off.

So, that’s basically the livewell aspects completed, here’s a few more photos to clarify the build and the installation.

Fitted and configured as a Dry Box

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Fitted and Configured as a Livewell

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The hand primer and valve assembly retain water very well with no visible draining with the pump off. However, the hand primer was positioned such as to allow easy operation when seated side saddle. Six to eight pumps are required to prime the system.

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The pump intake pipe is effectively almost flush with the hull of the kayak, recessed by only a few millimetres.

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The upper overflow pipe drains into the opposite scupper hole, with the lower drain exiting directly onto the floor of the tankwell. The internal pump and direct scupper drains should hopefully all minimise the livewell noise when in operation.

I’ve tried it next to the kitchen sink and it primes easily and works a dream. I’ll probably rig is tomorrow to see how long it will run on a medium setting of around 7 volts.

So there we have it, was it cheap??.. nope. I reckon is cost me about £100, though for a dual purpose container that’s no only durable but should be long lived.

22 comments:

Anonymous said...

Nice a lot of thought went into that, reminds me of the Hobie Live Well. The major difference between the two I see is that yours uses the priming bulb whereby the Hobie uses a forward facing fitting on its intake and it self primes itself when you start moving forward. Whats better? I dunno as Hobie's intake tubing's hangs below the kayak and yours fits flush with the bottom of the scupper and you don't have to worry about bottoming out on it. Almost looks like yours might be able to self prime itself the same way as you have the tubing cut an an angle similar to the forward facing fitting on the Hobie. Also yours has an advantage of being a variable speed unit as Hobie's is only a single speed. I also like the way your battery box is waterproof and Hobie's is not. Great Job!

John Griffin said...

Seriously Rob, you never cease to amaze, well done again. That must have been a lot of work just planning and sourcing the equipment, never mind building it.

The Nothing said...

I've read this over a few times on the TKF forums and i definitely like the build. While I cannot use live bait where I live, I would be able to compete in local bass tournaments, from my kayak, if I had at least a 60L livewell. Of course, we're talking about A LOT of weight at that point. How has the weight of your livewell felt in your kayak? Between myself, my average gear, and the 60L livewell, I'd be pushing the limits of what Ocean Kayak says the Trident 15 is capable of hauling...

Rob Appleby said...

I haven't actually paddled around with it fitted to the yak yet. Though full it takes under 40L, lower level is under 20L. I think the lower level will be used the most. The Big Game will handle it with ease, I've no worries there as it's very stable and has a huge capacity.

I'm not sure abou 60L though, sounds enormous!!. The Hobie livewell is under around 40L so you're talking 50% larger...

Mind you, you could always go on a diet and counteract it that way? :)

The Nothing said...

Would have to be an extreme diet. I don't have that much to weight to spare! Looked good in the back of your boat though (new 20# thornback article). I'm eager to hear how things handle.

Before I get to crazy, I'll fill my well with the appropriate amount of bricks to give me an idea of how things will (or won't) handle. The lower the profile, the better, and I'll probably end up putting together a custom job from fibreglass.

Anonymous said...

Rob, that is by far and away the best mod I have ever seen, it looks like it has come out of a factory. Not only is is well thought out, engineered with easy access it looks fanstastic which is quite often the most difficult thing to do by you have done it in style.

WELL DONE (excuse the pun)

Bucketboy

Rob Appleby said...

Cheers Bucketboy
I thought you'd like it. I honestly can't think of any other modifications I can do. That's a bit disappointing to be honest, I'll have to think harder :)

I tried it lat week purely as a drybox and it worked a dream. The only change I've made it to add an extra outlet for each level as it couldn't really cope on full flow.

I also added a removeable wooden divider which assembles in seconds inside the box which divides the bottom half of the box into 5 good sized compartments. It's also placed the pump into a small compartment of its own providng it full protection.

Jose C said...

Rob that is sick!!

you should definitely post this up on hckaclub.com forum. Im sure the guys could learn a lot from this.

I am going to have to try building one soon.

Anonymous said...

Thank you very much for sharing this great mod.
Can you tell me where can I get this container in Europe?

Rob Appleby said...

Good question, it depends where you are based. Put a search into your local search engine for 'vittles vault' and see what comes up.


Rob

YakSushi said...

Top notch build! Well though out and executed! Have you tried it with water in the well yet? I sent you an email.

Ryan Turner said...

Hi Rob, I am so glad i have come across your website! got myself a kayak a few months back and have been adding to it ever since...
Just started my live well project with a coolbox, 12v pump similar to yours. Everything was fitted tonight, (funny enough i did the same as you to get two levels of water in the tank) Then it hit me! my method of priming wouldnt work and have been racking my brains the last couple hours!!!!

Could you please tell me where you got the primer and one way valves from! would be amazing. Thanks, Tight Lines, Ryan.

Rob Appleby said...

The primer is a standard fuel primer. I modified it by taking out the small inelt/outlet pipes that were fitted as standard. The one way valve came from a local chandlers. It works just fine, though to be honest it's probably simpler to have the pump hanging in the water, that way it self primes.

Ryan Turner said...

I thought that... After drilling a load of holes in the coolbox. I saw a small bilge pump you just chuck in the water over the side and its as easy as that. I even see you bought a ready made speed controller circuit from maplin, i had a bit of fun making a timer circuit to make it run 2 minutes every 10 minutes.
Oh well, Its done now so i may aswell finish it.
Just ordered the fuel primer and ill get the valves tomorrow. Wouldn't i only need a single one way valve below the primer though?
Thanks for the quick responce and help by the way, you seem rather dedicated, amazing site by the way.

Rob Appleby said...

I thought one valve would have been enough, but it just didn't work as expected, hence two. The idea of the pump inside was to reduce noise underwater. If I was to do it again I'd probably chuck the pump in the sea purely for ease, that said, no complaints.

Thanks for the comments reference my site, much appreciated.

Ryan Turner said...

Hello again,
sorry to keep bothering you, thought you would be the one who would know this from experience... The primer pump came today (I ordered the 10mm valve size) the idea was i was going to remove the internal valves like you did.
However the pipe i am using has an internal diameter of 10mm and if i were to not take out the internal valves and order the 12mm primer pump instead, this would give a tight fit and would it have the same effect??? I do not need it to fill up or pump quickly anyway so do you reckon that would be ok?

Thanks a million already!

Rob Appleby said...

What you don't want to do is to restrict the flow of water too much. With my primer, if left unmodified, I'd have been stepping down from about 1/2" to an 1/8". I did try it and the results were awful!. You need an unrestricted flow, so matching the pipe diameters is quite important in my opinion.

Anonymous said...

Hi - I too am trying this DIY project. I am trying to buy the key parts first and already running into some questions. Can you describe the livewell pump you chose? I have a 500GPH Rule that may work. I am concerned about the pump being above water line in the kayak. Obviously this is why you created the hand primer, but some techs are telling me these pumps need to run continually underwater?? So do you hand prime until there is enough water in the livewell to cover the pump or is it enough just to hand prime until the water reaches the pump? and must you always have the pump submerged?

Rob Appleby-Goudberg said...

Hi, the Rule pumps are designed to run dry so it's a good choice for a pump. The shape/design of the pump will dictate its possible location. I mounted mine internally as I believed it would be quieter. However, it does complicate the setup it required a priming device. If I was to build a replacement I'd probably place the pump directly in the water and design it so the pump, feed pipe and electrical loom disconnected from the tank itself for easy storage, or for use as a drybox.

The hand primer pumped water to and through the pump itself, permitting the pump it operate correctly once switched on. The pump itself was unable to lift water several inches from the water level up to the pump itself without first being primed. You only require water in the pump for it to commence operation, it does not need to be completely covered.

David Dempsey said...

This project is incredible. Still generating comments almost 4 years after its design! This may have been asked elsewhere - but couldn't you prime the pump by filling the bottom of the baitwell with enough water to cover all or part of the pump? O

Rob Appleby-Goudberg said...

Hi, I later added a non-return valve onto the pump outlet to prevent water drainage with the pump switched off. Partially filling the livewell would therefore not prime it as it's currently put together.

Anonymous said...

Hi, I primarily bass fish and am curious if it would work well for bass or if its more suited for bass?