I just finished fitting a bilge pump to my CU-Fly using COTS* parts, Below is a step by step of how I did it, but some comments first:

This was built for expediency, from parts I could get at the chandlers across the road from me, and electronics from maplins; if you take time and have a think, I’m sure you could come up with a more elegant solution for the wiring, or at least make it prettier than I did.

I do feel that using a collection of commercially available Dry Cells rather than an expensive custom order Li-Ion or Sealed Lead-Acid battery as is popular in the US is a good idea though; when your rechargable D-cells finally die, you can pop down to the news agent and grab some energisers to tide you over until you can get a new set delivered.

Also important, as will become apparent, is that the method of fixing the pump down is pretty specific to the CU-fly (though something similar could work in a boat that uses a dagger saddle such as the quake or aftershock). I’m already considering how I’ll do this in the prelude, and screwing the pump to a thin piece of polythene cut from a broken kayak and welding it down, or screwing into a thin piece of WBP or Marine ply and adhering that down with some ABS Slurry (ideal solution for royalex and twintex hulls, not as good as welding for the polythene).

Finally, and given that most Canoeists are pretty good with their hands, this shouldn’t be an issue, please carefully consider what you’re doing, where you’re placing the pump, what the hose might foul on, how the hose is going to be routed, where the wiring is going to go, and what you’re going to attach the battery pack to. Think through it methodically several times and if necessary put all the parts in a “dry run” alignment, before you do a single thing to the boat.

*Commercial Off The Shelf

Materials:

• Bilge Pump (I chose a Rule 1000 Model 20A, because the local chandlers sells them cheaply)
• 0.5m Hose (same size as your pump outlet, I had 1 1/8 in)
• Outlet Plate (again same size as the pump outlet)
• Stainless Steel Pipe Clips (These need to be of an appropriate size for the hose)
• 4*Short Brass Screws
• Peli 1050 Micro Case
• Sub-Miniature Waterproof Toggle Switch Cover | Order Code: JR79L
• Sub-Miniature Toggle Switch A | Order Code: FH00A
• 3*Race Pk Lead Male | Order Code: JG04E
• 4*Race Pk Lead Female | Order COde: JG05F
• Universal In-Line Fuseholder | Order Code:PC78K
• 11/4in 31mm Quickblow F 1.1/4 QB 5A 10 PK | Order Code: GL81C
• Gland 5 – 8mm | Order Code: JR76H
• 8D Battery Box | Order Code: JG74R
• Soldering Wire
• Duct Tape
• Epoxy Resin
• Silicone Sealant

(Order codes are for Maplins)

Tools:

• Hole-saw (this needs to be sized appropriately to the outlet plate, I used 32mm)
• Drill bits (if you’re using the same parts as me, you’ll need a 14mm and an 8mm bit, a 5mm bit for pilot holes might be a good idea too.
• Drill
• Flathead Screwdriver
• Posidrive Screwdriver
• Heatgun
• Junior Hacksaw
• Soldering Iron
• Wire Strippers

Step-by Step:

Steps 1-8 are mounting the pump and hose, Steps 9-19 are making the battery assembly; these can be considered totally separate, and done out of order if desired. Steps 0 & 20 are the most important!

I suggest that you read this several times to confirm you understand what’s going on before you commit yourself by ordering parts or stuff like that.

Step 0:

Think very carefully about where you’re going to lay everything out, because almost immediately we’re going to start cutting holes in the boat.

Step 1:

First we need to make the hole for the outlet plate, using the hole-saw.

Step 2:

Attach the outlet plate.

At this point I should explain that the Rule 1000 splits into three parts,
the base (which includes the inlet), the nozzle (which includes the outlet),
and the motor. The other popular choice of pump, the Attwood Tsunami splits in two:
 the baseplate and the pump unit (which includes nozzle, outlet and motor in one).

Step 3:

Make the relevant holes in the pump base to attach it to the pedestal, Because I had self tapping screws, i just measured the distances, marked it out and screwed through.

Step 4:

Screw the Pump base onto the pedestal.

Step 5:

Warm the hose up with the heat gun (if your hose is nice and flexible, you may not need to do this)

Step 6:

Attach the (now flexible) hose to the barb of the outlet plate and secure it with a pipe clip.

Step 7:

Put the second pipe clip onto the hose (loosely, so it can slide), and attach the nozzle, attempt to mount it onto the baseplate; if necessary, rewarm the hose, or detach the nozzle and trim the hose down with the hacksaw, once it mounts comfortably on the baseplate, insert the pump unit and clip in into place; then tighten the pipe clip.

Now for the wiring bit... Remember to keep the Positive and Negative sides of the
circuit properly denoted by colour, Black for Negative, Red/Brown for Positive.

Step 8:

First we need to attach a female connector to the pump leads, so strip about 3/4 of an inch of wire on the connector and the pump leads, twist the two together and solder them lightly together, once the solder is cool, cover both joins with a thin layer of silicone sealant, let that set, and wrap the whole thing in duct tape.

Step 9:

More drilling now, we need to drill two holes in the lid of the peli case, one for the toggle switch and one for the cable gland. Chose where on the lid you want these, and drill through (do this on an offcut of wood or something & use gentle pressure, if you push too hard and drill through quickly you risk cracking the plastic, my drill bits had small pilot bits ahead of the main bit, if yours don’t, it may well be useful to drill a small pilot hole first with a quite narrow bit [5mm or so]).

Step 10:

Secure the cable gland into its hole, using a thin layer of epoxy resin on both the body and the securing nut to make a tight seal. Having done this insert a male connector lead through the gland, and secure it in place with epoxy, once the epoxy sets, seal both inside and out with silicone sealant.

Step 11:

Solder a second male connector to the one inserted though the gland, this time you only need to cover the join with duct tape (or insulating tape if you have it) because it will be inside the case.

Step 12:

Solder the positive end of a female connector to the positive end of a male connector.

Step 13:

Solder the negative end of the female connector to one of the contacts of the fuse holder.

Step 14:

Solder the negative end of the male connector to one of the ON poles of the toggle switch

Step 15:

Solder a short length of wire to the central (neutral) pole of the toggle switch, and the other contact of the fuse holder.

Step 16:

Insert a fuse into the fuse holder and close it.

Step 17:

Remove the retaining nut from the toggle switch, and leaving the washers in place, coat with a fine layer of epoxy (take care not to foul the inside of the mechanism) and insert through its hole; take the waterproof switch cover, bed the O-ring into its groove, and screw it down firmly on the outside of the toggle switch.

Step 18:

Seal the inside of the toggle switch with silicone.

Step 19:

Solder a female connector to the Battery Holder, take care to attach the leads to the correct polarity terminal, and to avoid any short circuits caused by stray strands of wire.

Step 20:

Connect it all together and test. periodically spraying some WD40 or another light, water-dispersing lubricant into the connector which is external to the battery assembly would be a good idea.