Fitting bilge pumps

On Rainshadow, we have two electric bilge pumps.

The main one is a Rule 2000, which is supposed to be the disaster pump. It was installed by the PO, using a mechanical float switch. It’s outlet is routed to the starboard bilge outlet on the as-built boat – that is, the one so close to the waterline that people have problems with back-syphoning when sailing hard on a port tack.

The second pump we added as a maintenance pump. It is a Jabsco ParMax 3 washdown pump, which obviously has a low flow rate. We use this to pump out the little water that accumulates during normal operation. We operate it with the electronic WaterWitch switch, and routed its outlet to a new thru-hull we added to the transom (i.e. – always above the waterline)

When we added the second pump, we mounted the ‘disaster pump’ and its mechanical float switch higher, out of the muck that accumulates in the bilge. The little maintenance pump has a small diameter exit hose (3/4″) and so the idea is that we have limited backflow into the bilge when the hose back-drains after the pump shuts off.

We learned a lot of lessons while getting this installed. If you like the approach we are using, I suggest you read our person blog here to learn from our mistakes before you try this in your own boat. The major lesson we learned is that the Nic 38 must have a deeper bilge than most boats, because its tough to find a little bilge pump that can overcome the back pressure created by the vertical lift required. (i.e. the head height).

Marilyn (Rainshadow)

Hiya Adrian –

Glad to show pictures of anyone’s boat at the top of the forum, read this topic to learn how. Thanks to the folks that have already sent me photos, we all can enjoy seeing others boats, randomly selected for each page you view.

Regarding whether its better for a pump to be regularly immersed or kept dry – I would imagine dry. Consider that manufacturers ship the pumps dry and expect them to work perfectly first time they are run… So we cleaned ours carefully, and then left it installed in what hopefully will be a high and dry position forever.

I think the item that benefits most from being dry is the mechanical float switch. The PO noted that the switch had occasionally stuck ‘on’! Therefore, he pulled the pump setup each year to clean it. That sounded like too much work, and risk, to us. With our new 2 pump setup, only the inlet strainer and electronic switch are submerged in the gubbins on a regular basis. We have had the electronic Water Witch get confused by the gubbins one time too, after a big roller tossed around the boat while underway – we had to manually shut off the pump and then later the switch problem fixed itself. We have done our best to clean out the bilge with a wet/dry shop vac too, and keep the cabin floor clean to minimize dirt ingress into the bilge, but somehow the gubbins still multiple down there.

Cheers – Marilyn

Hi Peter –

Clever Van, my captian and co-owner, mounted all bilge pumps, switches and sensors on a vertical plastic “board”, which lowers into the bilge and is held in place by mounting to the “bulkhead” above the gearbox. Having everything mouted on a removable board not only means he could do the work in the first place (as sneaking past the shaft to the depths of the bilge is indeed impossible for the average yoga yachtsman) – but also yearly maintenance is easier because he can pull up everything mounted to this board and work on it in a more comfortable position than having your head hanging in the bilge.

While at a DIY store, Van found this hollow plastic 6″ wide board meant to be used for house deck railings. He shaped it to size, figured out the correct mounting positions for everything (through trial and error with much cursing I am certain) and then eventually bolted in place the board with attached bilge equipment. It took several iterations to get it all functioning, and I believe he is still not happy with it. The idea of the plastic hollow board meant it’s lighter weight, and won’t rot like wood will.

Van’s not here right now – I’ll have him read this later and see if he has more to offer. Sadly, we have no pictures of this, so I hope you can imagine how it looks via this description.

Cheers –
Marilyn

Hi Peter,

My first attempt using the plastic railing is not satisfactory because it’s a bit flimsy and too wide to easily get past the shaft. So, when I’m putting it into place, the floats and pumps tend to shift unless I’m careful.

One additional point, if you make the length just right, then the board can hold down a strum box firmly to the bottom of the bilge.

When it warms up here, I’m switching it to a pressure treated wood 2″x4″.

Van

Long overdue I have just installed an automatic float switch of the correct amperage, and another higher in the bilge with an alarm should water ever reach that level; these are mounted on a strip of aluminium which allows them to be lowered and fixed appropriately. A similar strip of aluminium (both present on my original purchase of Chihili Q) is welded onto a hoop of similar material, itself secured to a baseplate bolted onto the the strum box of a Rule 3700 bilge pump. This means that the bilge bump can be raised and sniffed, stroked or whatever.

I had wondered about replacing or servicing the pump, not knowing it’s true provenance, but a bloke at Safety Marine said not to worry, they don’t need servicing, “good for life”. Never-the-less, my new float switches required wiring and having done a radical job I tugged on the wire from the pump deep in the bilge, protected by “ducting” and found it almost severed through except for a few strands of copper. Oops, better replace the pump after all; in the event this ressembled delivering a baby and putting another one in it’s place: quite a challenge given my existing aluminium cradle/basket thing for holding the pump in place, but at least Chihili Q didn’t struggle or cry out. Afterwards I found another near break in the wiring where the Rule wiring had been connected to secondary wiring. Either of these connections could have “gone down” at any time. If my pump did fail to work, I would almost certainly have blamed my new wiring, not the pump and its immediate connections. Beware!

And watch out for so called “Marine” electricians; in my experience they employ household type electrician apprentices, judging by the materials and connections used, which can lead to all sorts of interesing surprises!

Cheers, Adrian.