Bilge Pump Outlet - advice needed

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Ehbendisdonc

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I'm about to fit a manual bilge pump to my Corribee. I would like to bring the 1.5" outlet pipe to a skin fitting within the cockpit footwell (rather than add a through-hull fitting). I would also like to terminate a separate hose with a fitting that would push into that outlet. With this configuration then, the pump would normally discharge into the cockpit but I could also plug in the additional hose and discharge it overboard.
My question is - can this be easily achieved using standard fittings? Has anyone out there done something similar?
 
Sounds ok but make sure you loop the pipe up under the cockpit seats or locker before you drop down to the skin, fitting to prevent your cockpit draining into the bilge if you take a wave on board or the cockpit drains block. (much safer than relying on one way valves in the pump or pipework)
 
2Tizwoz - Thanks, I chose a large capacity pump 'to be sure to be sure', as it doesn't take long to sink a small boat. Think I can accomodate the 1.5" hose, but will consider stepping it down if have to.
Pete - good point about adding a loop. The problem on this boat is that is no room to run a loop higher than this outlet. The outlet will be high up in the cockpit well, just below the level of the washboards. I may just seal it off when not in use so the scenarios you describe cannot occur.
HLB / P'Fleur - Thanks for your replies. Hopefully I can engineer what I need from standard fittings - I'll try the local builders' supplies as well as the ASAP catalogue.
 
Route it overboard.
You do not want bilge water sprayed over the cockpit everytime you check the pump works.
Hose size needs to be about right for pump capacity, too small and it becomes very hard work to pump at any speed. too large and priming can be affected if the pump is high up.
 
A few comments:
- If there's one place on a boat that you don't want unnecessary problems, it's on a bilge pump if the boat is sinking. Plugging in an additional bit of hose is highly likely to give problems - it will fall out, then something will get into your cockpit drain and you'll finish up pumping the water back into the boat via the companionway. Much better to get the water over the side straight away. I can't really see the benefits of your proposed scheme anyway.
- Lifting the water over the guard wires will reduce the efficiency of the pump. Keep the discharge as low as possible to get maximum flow.
- As has been said, bilge water is mucky stuff. Why tip it over the cockpit floor?
- A positive displacement pump has two non-return valves in it already. Water will not flow back down the outlet pipe into the boat unless the pump is not functioning. A loop is very much advised but not the end of the world if you can't fit it. A compromise might be to fit the outlet skin fitting above the normal water line.
- Site the pump so that you can operate it for a very long time without becoming exhausted. Believe me, the 'frightened man with a bucket' theory is total rubbish: I've been there and I kept it going for about five minutes. Best place is standing up so you can operate the pump by rocking back and fore, using your legs. Wherever it is, try out a mock-up first and pump for 15 minutes.
 
I'd too go with a direct overboard discharge although assuming you dont have an inboard engine I dont know why your bilges would be as foul and oily as everyone seems to thing they will be. (mine aren't and my bilge pump discharges into the cockpit because I still have not got round to fitting the skin fitting for it!)

Some versions of the Corribee have the cockpit floor only very sightly above the water level. If that applies then maybe another good reason for going for the overboard discharge.
 
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Believe me, the 'frightened man with a bucket' theory is total rubbish

[/ QUOTE ]
I endorse that sentiment. I found my cabin sole deeply awash last July in a rough sea and had to utilise my only bilge pump, a manual Whale Gusher, that, after ten minutes, made me realise just how limited it was and how exhausted I had become. As I was alone it would have been only a matter of time before I sank if I hadn't found the cause.

Back in the marina my first job was to fit an automatic electrical pump in the deep bilge sump. I have vented the outlet into the cockpit (rather than tee into the existing piping or install another skin fitting) where the discharge does not cover the cockpit sole when running - and I echo those who say their bilges are not oily, mine certainly isn't because I regularly keep it dry and clean and the engine has its own sealed sump area (which I also keep clean).

An automatic pump should have an alarm when activated - it's no good to have water coming in and automatically going out without being aware of it - and having the pump discharging into the cockpit is a good alarm indicator.
 
Almost certainly no good to you, but something I thought was sound practice. Older french fishing boats had all their water outlets on the side of the deckhouse discharging into a hopper, from which a large pipe drained overboard. No skin fittings to fail, and easily visible.
 
I had a Corribee. I was permanently wearing wellies in the cockpit, as the current cockpit drains are only about an inch above sea level, so it drains slowly.

Send it overboard, or it will make the boat even more sluggish whilst the bath is emptying.

In fact, I would be tempted to mount the bilge pump in the cockpit sole. /forums/images/graemlins/laugh.gif
 
Before I am accused of having oily bilges, I will be quick to announce that I do not. However, I do suffer the minor but irritating weep from my secondary diesel filter that featured in a thread a couple of weeks ago. Equally, I very rarely have water in my bilges either, most usually when I do it has been put there to clean out the aforementioned diesel, using biodgradable detergent, naturally. On other occasions water gets in there when my raw water pump fails to prime and I am forced to mess about with the strainer and sometimes the hoses to get it going again. Inevitably there will be a smear of diesel in the bilge and a little diesel goes a long way.

I see no good reason for pumping this mixture into the cockpit, much better over the side.
 
No worries about oily, smelly bilges as I don't have an inboard. Also, pumping it out through the guardwires involves only about a foot of additional height over and above the proposed outlet. It's a small boat.
One thing that does make me a little nervous about discharging to the cockpit is the possibility of the drains becoming blocked, or pumping into an already full cockpit if pooped.
The problem with discharging through the hull is that, with such a low freeboard, the discharge point won't be far above the waterline and I still won't be able to incorporate a loop above the level of the discharge point. Also, routing it through the cabin won't be easy, though I may be able to site the outlet within the chart table cabinet.
Thanks to everyone for their advice.
 
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