Thursday, June 03, 2010

Fitting an electric pump to a sea kayak

An electric pump will allow you to start paddling and bracing immediately after performing a reentry and roll in rough conditions. I believe it makes a significant contribution to your overall safety in challenging conditions, should the worst happen and you find yourself out of your kayak.
There are many different web pages on how to do install a pump but many are complicated, involving many connections switches, relays and connections and some are compromised by the owners reluctance to drill a hole in the kayak. In a marine environment, the more connections you have, the more likely it is that one will fail.

I have chosen a different approach, which uses a minimum number of connections. The Rule 25S-6WC 500GPH automatic bilge pump is designed for jet skis. Inside the pump body an electronic circuit spins up the pump for about a second every 20 seconds. If no resistance (water) is met then it switches off. If resistance is met, it will carry on pumping until air enters the pump inlet when it will stop. After this it will go back to spinning up every 20 seconds. (Some other Rule automatic pumps spin up much less frequently and are therefore unsuitable for kayaks.) The battery draw is negligible. I used it for 10 days in the Outer Hebrides and at the end of the 10 days there was enough battery power to empty the kayak several times. I have chosen not to use a switch or a fuse. I chose to use a sealed lead acid battery because the pump is 12 volts and if you were to use rechargeable AA batteries you would need 10, which is a lot of connections! Also most NIMH AA rechargeable batteries don't hold their charge in storage and it is a hassle to charge 10 just before you go out. They also have poor cold weather performance compared with a sealed lead acid battery.


Rule 25S-6WC pump
12v 1.3Ah sealed lead acid battery fitted with...
snap together connector which is soldered to the battery terminals.
(I used to use simple spade connectors straight onto the battery terminals but I found they came off.)
12V SLA trickle charger, don't try to use a car battery charger on a small battery like this!
Some 3mm sticky backed foam to stick on the back of the battery and the bulkhead, where it will fit against.
Velcro hook and loop tape to stick onto the foam pads on the battery and the bulkhead. (I found you get a better "stick" using the foam between the Velcro and hard surfaces.)
A 3/4" skin connector for the hose.
About 10" of 3/4" hose
Unibond "No more nails", waterproof adhesive, which is much more effective than silicone sealant.


The fun starts drilling the hole with a hole saw. I like to put pumps in front of the footrests, next to the forward bulkhead. Put some tape over the gel coat and drill very slowly.


Bed the connector in a little adhesive and screw it up from inside. Glue the pump mounting base (blue) to the hull, because of the vee bottom, I have stuck it slightly off the mid line to get it square on the hull. It is best to roughen the pump base and the hull with coarse abrasive paper then clean both surfaces with a solvent such as alcohol. Leave the pump base glue to dry for 24 hours then fit the hose, heating it in hot water will make it more flexible. Clip the pump into its base. Now drill two 3.2mm diameter holes in the middle of the bulkhead and push the wires through to the front compartment. Seal on both sides with glue. Leave enough wire to bring the pump back to the cockpit opening for cleaning its filter (if it ever gets blocked) and use cable ties to secure the loose wire to the hose.


Working in the front hatch, solder the connectors to the wires. Working outside I find it easier to use one of the little high temperature jet butane lighters than a soldering iron.


Push the plastic connector on to the two terminals and give it a good spray with water dispersant.


Now the whole lot can be assembled together and the battery stuck to a Velcro pad on the bulkhead. You will now hear the pump spin up then stop every 20 seconds until you pull the connector apart. The connector can only clip on one way so you will not be able to reverse the polarity by mistake.


I have tried three different one way valves in the hose. Even the best reduced the flow rate by 50% so I don't bother. You can fit a kitchen sink plug to the outside of the connector. Some people suggest putting a loop in the hose to prevent sea water coming in through the pump but the Rule instructions specifically warn against that as it can create an airlock which will stop the pump.

Does it work?


You bet it does and its simplicity makes it reliable!!


This is why I do not like switches. This switch was mounted in the day hatch with a waterproof boot covering the toggle which went forward through the rear cockpit bulkead. It has seen three seasons' use and was sprayed twice per year with a Suzuki brand wax spray for protecting outboard motor electrics. It did still work when it was removed but for how much longer...?

There are some other links to installing pumps,
Here
Here
Here and
Here

Friday, May 28, 2010

A crusade by sea kayak to the Holy Island


A 20km paddle from Brodick on Arran round Holy Island, March 2010.

The north going flood tide enters Lamlash Bay by the South channel and exits by the North Channel the south going ebb tide runs in the reverse direction.

N going flood +0605 HW Greenock -0500 HW Dover, 1knt springs S channel 0.75knt N channel
S going ebb +0040 HW Greenock +0200 HW Dover, 1.5 knt springs S channel 1 knt N channel

Lamlash tidal constant -0025 Greenock +0050 Dover


Destination Holy Island!


The mountains of Arran

No egos at Portencross!

Seeking shelter in Brodick Bay.

Egalitarian cruising on the Clyde

Little and Large in Lamlash Bay.

Do Holy Island monks think they are above the Law of Scotland?

The west coast of Holy Island, Arran

The Inner (and Outer) Light of Holy Island

Tony hangs up his hat on Holy Island

End of a Crusade to Holy Island


Photo album map

Monday, May 24, 2010

She sailed of into the sunset...


We did not have long to get changed and get the kayaks ready as the Arran ferry arrived at Brodick not long after us. We soon boarded and made our way to the dining room.


After a very pleasant evening meal of Calmac chicken curry and chips it was time to return to the kayak deck, ready for disembarkation at Ardrossan on the Ayrshire coast.


We had just loaded the kayaks on the cars in the time it took the MV Caledonian Isles to reload with another set of cars and passengers on their way to Arran.


Then the MV Caledonian Isles...


...sailed off into the sunset...


...which grew deeper by the minute. Our Arran adventure was over.

Sunday, May 23, 2010

End of a Crusade to Holy Island


We left the shady beach on the east coast of Holy Island and paddled towards the north and the sunlight slopes beyond.


Crossing the north entrance to Lamlash Bay we took one last look back at the distinctive outline of Holy Island, the subject of our recent crusade.


Passing low Hamilton Isle, we made our way to the...


...tumbling slopes of Clauchlands Point round which,


Arran's snow covered peaks came into view one after the other.


Reluctant for our paddle to come to an end, we loitered in Brodick Bay as long as we could, as our ferry, the MV Caledonian Isles, steadily increased in size on the eastern horizon.


All too soon our time on the water was coming to an end. None of us knew it then, but this would be the last time that Tony and the second last time that Phil and I would paddle with our good friend Jim.

Wednesday, May 19, 2010

Tony hangs up his hat on Holy Island


We left the sunshine as we paddled north up the east side of Holy Island...


...and entered the shade under the steep slopes of Mullach Mor (314m). In the distance the snow covered slopes of Goatfell were still in full sun.


We stopped at a remote, stony beach to stretch our legs and enjoy a quick (it was cold) bite to eat. Tony and Jim looked out over the Firth of Clyde to the barely visible Ayrshire coast beyond.


All round the top of the beach there was the sadly all too common plastic tat of flotsam and jetsam etc. Always with an eye for the camera, Tony modelled a fetching helmet in an attractive shade of sky blue.


The monks had erected this tasteful plastic post, adorned with a goodwill message in four languages. Tony was impressed by its simple message.

Tuesday, May 18, 2010

The Inner (and Outer) Light of Holy Island


At the SW corner of Holy Island we came to the Inner Light. No it is not some higher plane of enlightenment merely a NLB lighthouse.


We then rounded the southernmost point of Holy Island only to discover...


...another lighthouse which is named, with a great deal of logic, the Outer Light. Perhaps, to continue the Harrison analogy, a case of within you, without you.

Why might you ask should Holy Island be blessed by illumination by two lighthouses so close together? Perhaps it is because Lamlash Bay is one of the great natural harbours of the World. Although it is not bordered by any great centre of population, it provided shelter for ships of the Royal Navy in both World Wars and as a relay point for convoys. Somewhat before the construction of the lighthouses, King Hakon IV of Norway gathered his fleet of Viking long boats here before his defeat at the Battle of Largs in 1263.