Fitting a Pump: a Practical Guide


“Doesn’t handle too well when it’s got a bit of water on board,” said Rob cheerfully when I took the Greenland T out for a test paddle.  It was a beautiful black boat, I fell for it straight away… but it’s a wet ride and does ship a bit of water.  No problem, I’ll just fit an electric pump. Been there. How hard can it be?

I had the benefit of two terrific articles, one from Gnarlydog News and another from Shawn Armitage of the Hunter Kayak Klan, setting out in confident and unambiguous detail how to make a magnetic switch and install a pump in a T. Very clear, very encouraging.

I decided a magnetic switch was the go. My mate Matt built one, the instructions are straightforward, it’s only a switch after all. And so my journey commences. The days below span several happy weeks.

Day 1: Off to Whitworth’s with my list.  Sikaflex, ugly white acetal outlet fitting, spade clips, black plastic ball to hold the magnet.  They don’t stock the pump I’m after (the Rule Amazon 280GPH inline pump), but I’ll mail order one. From nearby angling shop, buy a cheapo pelican-style case for the battery.

Trips to Whitworth’s = 1

Day 2: Pop into Jaycar, crikey what a seriously brainy bunch they all look. Buy a battery, three reed switches, a relay switch, and a metre of heatshrink tubing. What fun! On way home call in to the bottle shop to pick up my good mate Captain Morgan.

Trips to Jaycar = 1

Day 3: Order pump from Whitworths, $84 (doesn’t count as a trip).  Dig out a bunch of electrical wire. Spend an hour finding soldering iron. Put off doing soldering. Consult the Captain instead.

Day 4:  No means of securing battery case to boat. Hmmm. Off to Whitworths, buy some epoxy putty, a bunch of saddle clips, some shock cord and olive cleats. Also buy the rather cute $4.95 fuel breather valve (black), the hero of this story.

Trips to Whitworth’s = 2

Day 5: Pump arrives. Huzzah! Bilge pump fails on neighbour’s stinkboat, it’s sinking slowly, no worries, I’ll save the day with my new pump!  An hour later pump fouled with toxic sludge from the rotting bilge. Hmmm.  Flush it furiously. Hope it’s not compromised. Seek the Captain’s advice.

Day 6: Realise I can’t make the switch work, I haven’t got any magnets. Trip again to Jaycar (seriously brainy bunch) where I find rare earth magnets are sold in convenient packs of eight. Great, seven spares.  Get home, spend an hour finding soldering iron, set up, hmm, haven’t got any 2-core cable, and the heatshrink has run off with the acetal fitting and neither can be found. Some more water tubing wouldn’t hurt.

Trips to Jaycar = 2

Trip to Whitworth’s in order!

Day 7: Off to Whitworths. Cable, more spade clips, acetal fitting just in case, 13ml tubing,  some Sikaflex, white this time so I’ve got both colours.

Trips to Whitworth’s = 3

Day 8: OK, the Sikaflex I bought on Trip 1 was also white. Bugger. Never mind: find soldering iron (only ten minutes, ha!) and get to work fabricating circuit with battery and relay. Embed reed switch in block of epoxy resin. Put 1/8th of my magnet supply in the plastic sphere.  Cram battery and relay into pelican case, Sikaflex wire outlet. Test. All works. The Captain and I celebrate.

Day 9: Pump-fitting day! Put the beautiful boat on the sawhorses in the backyard, take out the seat (skin knuckles, curse).  Take deep breath, drill hole in bulkhead from cockpit to day hatch. Glue magnetic switch in place to inside deck, take off deck lines, fit magnet. Run cables back into day hatch, and cut pump cables to fit as well. Drill exhaust outlet, fit that black fuel breather vent (looks brilliant!). Make up a hose to go from the lowest point of the hull to the pump, make a stainless mesh gravel filter, attach to a hose fitting and secure to hull floor.

Sikaflex the hole, cables to hull, Velcro to hold pump, and screwdriver to boat floor (accidentally). Secure saddles in day compartment with epoxy resin. I am so damn clever. All very neat except the screwdriver, which comes off eventually. Connect up the battery, test.

Does not work. Nothing at all. Dark by now. The Captain and I commiserate.  I draw up test circuits to isolate the problem. Captain helpful as ever.

Day 10: Test out the circuits. Yep, it’s the switch: every other configuration works. Make up new switch: more wires and resin. Before cutting old switch out, test the new one with magnet. Switch goes on! Huzzah! Switch stays on! Bugger.  Turns out reed switches can be permanently magnetized. And me without my degausser!

Decide to test pump setup, so connect to battery and relay without switch. Half fill boat with water, turn pump on. Satisfying whirring noise, unsatisfying absence of water being pumped. Unvelcro pump, check for obstructions. Clear. Cycles happily.  Stand in water vertically and spurts like crazy thing.  Reattach hose to inlet, put on side, refuses to shift water. Surmise the rotor is inadequate to evacuate the air when it’s on its side. Bloody thing needs to be more upright.

Day 11: Overcast. Can’t work. Review progress with the Captain.  On Captain’s advice decide to abandon magnetic switch and go with the old faithful toggle.

Day 12: Off to Whitworths! The staff greet me with excessive familiarity and assure me that the sniggering noise they’re making is just a bad head cold they all have. Two toggle switches (a spare ready when the first one fails), a fuse and some black Sikaflex.

Trips to Whitworths = 4

Back to work!  Drill another hole in the boat, no hesitation by now. Bung in toggle switch. Rip relay out of the pelican case, pull out the wires, fit a fuse and a simplified wiring.  Use a tiny bit of hose to connect the pump and exhaust so the pump is more vertical, lash in place with cable ties. Discard lovingly crafted steel mesh grit filter, substitute a bit of flyscreen over the inlet. Test. It works! Fit spade clips to all the exposed bits of wire and call my beloved to come and look.

Triumphantly explain the travails and theatrically connect last remaining wires. Blue spark, emphatic popping noise.  Oops, in my enthusiasm I’ve short circuited the thing. Last item I did this was with a $2,000 video camera and it never worked again. Nothing works here either. Bugger. Have I blown up the battery, the pump, or both? Captain nowhere to be seen.

For once it’s not a disaster. The 30c fuse! It blew instead! Replace that, dear God it all works.  Cram the rat’s nest of wiring into the day hatch, lash the pelican case in place, and fit seat again (skin knuckles, curse).

As usual, wonder what the left-over screw was for.  Undo seat and fit it again, properly.

Captain still nowhere to be seen.

Two days later: paddle from Balmain to Clifton Gardens, do a few rolls, pop the skirt and fill with water. Not without some trepidation reach back to switch. Sounds like a Blackhawk helicopter firing up but blow me down, the thing actually works! Paddle cheerfully home deliberately shipping water just for the joy of hearing the pump. Once home discover the battery pack has fallen loose from its moorings during the rolls but the tangled swirl of wires now filling the day hatch prevented any harm. Such foresight.

A couple of days later Shaan asks about pump. Tell her of my enthralling experience and offer to help fit one to her pristine boat, no problem, happy to lend a hand. I’ve got a few spare bits, after all.

Still waiting to hear back.