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Bilge Pumps- electric

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Created by kimtrang > 9 months ago, 10 Jun 2017
kimtrang
55 posts
10 Jun 2017 7:42AM
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I'm looking for an automatic bilge pump. What can seabreezers recommend? Is a separate float switch a better idea?

Trek
NSW, 1149 posts
10 Jun 2017 1:14PM
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I found the electronic sensor ones a pain and a separate float switch is better.

The reason is the electronic sensor eventually gets growth on it and stays damp after the pump has emptied the bilge. But the pump sees the damp growth on its sensor and keeps going until its impeller or something else fails. The alternative is to clean the sensor all the time.

Bristolfashion
VIC, 490 posts
10 Jun 2017 5:51PM
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I've got the Rule pump and separate float switch. Works a treat and you can always seitch it on manually if the float switch fails.

Cheers

Bristle

Ramona
NSW, 7584 posts
10 Jun 2017 6:38PM
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I would suggest separate pump and switch.

For the switch there is really only one choice. They are expensive but superb.

www.whitworths.com.au/swch-waterwitch-mini

Charriot
QLD, 880 posts
10 Jun 2017 7:08PM
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Separate switch is way to go, as was already suggested , also
very important is offset the switch. The pump must by fully submerged before kiks in, in any boat movement.
Mine was set by previous owner, working ok, until first gale going through marina, pump was sucking the air, and runs until battery was completely dead.

Ramona
NSW, 7584 posts
11 Jun 2017 8:34AM
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Charriot said..
Separate switch is way to go, as was already suggested , also
very important is offset the switch. The pump must by fully submerged before kiks in, in any boat movement.
Mine was set by previous owner, working ok, until first gale going through marina, pump was sucking the air, and runs until battery was completely dead.


Fit a Water witch and you will never have that problem.
www.whitworths.com.au/swch-waterwitch-mini

They are really a clever piece of kit.

Andrew68
VIC, 422 posts
14 Jun 2017 10:21AM
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Ramona said..

Fit a Water witch and you will never have that problem.
www.whitworths.com.au/swch-waterwitch-mini

They are really a clever piece of kit.


Total agree with Ramona here.

IMO the standard water witch with a separate pump (ideally a diaphragm pump designed for bilge water) works best. The great thing about the water witch is that you can place it exactly where is needs to be and it's easy to clean.

I have had all sorts of troubles with integrated centrifugal bilge pumps. And others do too : from time to time, I can hear the echo of a bilge pump flattening batteries somewhere in our marina running stuck or cycling.

They are fickle little things. I made up a test bench at home and was surprised how they seem to work perfectly then fail when you least expect it. Test them thoroughly. Fill them quickly, fill them slowly, can they suck air, will they work on an angle, or with vibration or with water sloshing in from the through hole fitting ?

Some of the issues are :
-float switches getting stuck : the smaller integrated float switches wear at the hinges and get gunked up sticking closed or open, can work well in the marina, but can get stuck on an angle when heeling.
-cycling : water left in the outlet hose drains back filling the bilge turning the pump on again and repeat. One solution is to use a non-return valve.
-non return valves : avoid them, if possible. They get clogged with gunk, stuck with back water pressure or get air locks. Some pumps have a tiny hole that drains the water from above the non-return valve to assist here. You need to make sure that hole is clean and never ever gets blocked.
-Gunk and grunge caught up in the tiny impellors
-Air in the impellors
-Not enough offset between switch and intake leading to cycling

Out of four integrated units I played with, I found the Rule Lowpro seemed to work best, but I can still get it to cycle or fail in some situations. It needs to be cleaned regularly.

A

Ramona
NSW, 7584 posts
14 Jun 2017 6:08PM
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If you don't want to install a Waterwitch you can jerry rig a standard float switch. Start with a Rule float switch and mount it well clear of the water {they don't like water}. Use a table tennis ball glued to a lightweight stick and rig that to push up the float switch. Another set up I used for years was a washing machine vacuum switch mounted several feet above the bilge water. 3 inch plastic tube with a cap then down to 4mm tube to the switch. As the water rises air pressure makes the switch.
The Water witch is the only real answer and the time delay where the pump only turns on the pump when the level is actually rising will save those batteries from running flat

kimtrang
55 posts
14 Jun 2017 8:17PM
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Thank you all for the responses. I bought a WaterWitch switch and 2 Rule pumps (a 900 g/h LoPro and a square 1000g/h). Didn't realise Whitworths have Rule 1100 g/h on special for $50, so might return both and get a few of them. Already have a Rule and 2 Johnson standard float switches that came with the boat. I'm not sure of their condition, but I'll test before I buy another.

Andrew68- can you recommend an diaphragm pump? There is the Jabsco Puppy, but apparently it isn't what it used be and has some reliability issues.


Ramona
NSW, 7584 posts
15 Jun 2017 8:10AM
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Select to expand quote
kimtrang said..
Thank you all for the responses. I bought a WaterWitch switch and 2 Rule pumps (a 900 g/h LoPro and a square 1000g/h). Didn't realise Whitworths have Rule 1100 g/h on special for $50, so might return both and get a few of them. Already have a Rule and 2 Johnson standard float switches that came with the boat. I'm not sure of their condition, but I'll test before I buy another.

Andrew68- can you recommend an diaphragm pump? There is the Jabsco Puppy, but apparently it isn't what it used be and has some reliability issues.




The problem with the rule type float switches is they go on and off when boats go by and the yacht rocks a bit. They also jam easy when there is loose stuff about.
The best bet with the rule pumps is to carry a spare. Wire them up to a junction box well clear of bilge water so that a replacement can be installed with the minimum amount of tools.

The Waterwitch switches used to have a life long guarantee. They don't anymore but you will have it for a very long time!

Andrew68
VIC, 422 posts
15 Jun 2017 11:51AM
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kimtrang said..
Andrew68- can you recommend an diaphragm pump? There is the Jabsco Puppy, but apparently it isn't what it used be and has some reliability issues.


I was recommended the Jabsco 50880 Diaphragm Bilge Pump and it has worked flawlessly with a Waterwitch.

www.jabsco.com.au/uploads/4/5/4/4/45448347/mtc_08_general_purpose_pumps.pdf

Andrew

Cav30
NSW, 121 posts
15 Jun 2017 1:55PM
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How many mm's of water in bilge will it take to activate the water witch? Thanks v much.
Ed.

Andrew68
VIC, 422 posts
15 Jun 2017 5:28PM
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Cav30 said..
How many mm's of water in bilge will it take to activate the water witch? Thanks v much.
Ed.


If you laid it flat it would trigger in 1" off water (in calm conditions), I guess.

waterwitchinc.com/wp-content/uploads/2015/11/Model-101-Techsheet.pdf

A

woko
NSW, 1592 posts
18 Jun 2017 8:27AM
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While trying to size a bilge pump I came across this chart, if a 1" hose or seacock fails 1' below the waterline your going to be looking at 19.4 g/m or 1164 g/h.


Trek
NSW, 1149 posts
18 Jun 2017 9:09AM
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woko said..
While trying to size a bilge pump I came across this chart, if a 1" hose or seacock fails 1' below the waterline your going to be looking at 19.4 g/m or 1164 g/h.



Thanks Woko thats something I never thought to work out. Ill be looking at the gallons per hour of my bilge pumps asap, all my hoses are 1 1/4". No wonder boats sink!

Andrew68
VIC, 422 posts
18 Jun 2017 7:51PM
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Trek said..


woko said..
While trying to size a bilge pump I came across this chart, if a 1" hose or seacock fails 1' below the waterline your going to be looking at 19.4 g/m or 1164 g/h.





Thanks Woko thats something I never thought to work out. Ill be looking at the gallons per hour of my bilge pumps asap, all my hoses are 1 1/4". No wonder boats sink!




See Why Did Inception Sink ? - Appendix F

www.sailing.org.au/sport-services/safety/major-incident-reports/port-fairy/

One of my favourite reports out there.

A

kimtrang
55 posts
20 Jun 2017 6:53PM
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After studying my bilge[s] I've decided on my set up. I have two separate bilges- one under the engine and the main just aft of the bolt on keel with a fuel tank dividing them. There is also a very small one between the fuel tank and main bilge. I think this was the access point for the original tank which was fiberglass and at the bottom of the keel beneath the existing tank. In total there are around 8 bulkheads in the keel which makes things tricky.

I returned the 900g/h Rule LoPro and Rule 1000g/h and bought 4x 1000g/h Rule ($50 on special at Whitworths) and a 3700 g/h Rule. Two of the 1000g will have a WaterWitch switch and be at the bottom of the main bilge, port and starboard. The 3700g will be be above them again with a WaterWitch to cope with massive influxes.

The engine bilge already has a Whale Compac 50 manual pump and another the same will be added to the main bilge. A 1100g will go there. Not sure I should connect a WaterWitch as it will invariably there will be oil leaked from the 40 year old Volvo MDII 25hp. I'm cleaning it up now and hope mini spill booms will keep it from polluting. I'll keep the last 1100g as a spare.

It it is an imperfect setup given the way the bilges are. I'm thinking of installing 3" or so PVC pipes connecting the bilges so it doesn't flow across the fuel tank when the engine bilge overflows. Maybe later I'll install another high capacity pump in there later. It's an expensive set up, but I feel I need it as I won't be getting insurance.

Thank you for your assistance.

Main bilge to the right and engine on left. The bilge under the engine is quite inaccessible. Yep, that is rot from water leaks in that timber beside both sides of the engine. It's not structural- just a fascia.




Bushdog
SA, 309 posts
21 Jun 2017 2:29AM
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Select to expand quote
woko said..
While trying to size a bilge pump I came across this chart, if a 1" hose or seacock fails 1' below the waterline your going to be looking at 19.4 g/m or 1164 g/h.



This chart IS an eye opener. Take a mid example - 2" hole 2feet under water. 110 gallons per minute = 6600 gallons per hour. That'll easily overwhelm even a 'large' electric bilge pump with 3700 gah capacity, especially when capacity will be reduced to about 2000gph by outlet width and head height (not the dunny, but how high the water has to be lifted before it exits the boat). I'm presuming that the chart refers to Imperial gallery no, but even if they're US gallons, it ain't looking pretty!

Ramona
NSW, 7584 posts
21 Jun 2017 8:06AM
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Select to expand quote
kimtrang said..
After studying my bilge[s] I've decided on my set up. I have two separate bilges- one under the engine and the main just aft of the bolt on keel with a fuel tank dividing them. There is also a very small one between the fuel tank and main bilge. I think this was the access point for the original tank which was fiberglass and at the bottom of the keel beneath the existing tank. In total there are around 8 bulkheads in the keel which makes things tricky.

I returned the 900g/h Rule LoPro and Rule 1000g/h and bought 4x 1000g/h Rule ($50 on special at Whitworths) and a 3700 g/h Rule. Two of the 1000g will have a WaterWitch switch and be at the bottom of the main bilge, port and starboard. The 3700g will be be above them again with a WaterWitch to cope with massive influxes.

The engine bilge already has a Whale Compac 50 manual pump and another the same will be added to the main bilge. A 1100g will go there. Not sure I should connect a WaterWitch as it will invariably there will be oil leaked from the 40 year old Volvo MDII 25hp. I'm cleaning it up now and hope mini spill booms will keep it from polluting. I'll keep the last 1100g as a spare.

It it is an imperfect setup given the way the bilges are. I'm thinking of installing 3" or so PVC pipes connecting the bilges so it doesn't flow across the fuel tank when the engine bilge overflows. Maybe later I'll install another high capacity pump in there later. It's an expensive set up, but I feel I need it as I won't be getting insurance.

Thank you for your assistance.

Main bilge to the right and engine on left. The bilge under the engine is quite inaccessible. Yep, that is rot from water leaks in that timber beside both sides of the engine. It's not structural- just a fascia.





I would suggest wiring the Waterwitch to two of the small pumps and wiring the others direct to a switch. I would also suggest not using the reinforced plastic hoses anywhere in the bilges or engine bay. Use rubber. The plastic hose will harden from UV and engine heat and just bilge water and will not stay tight with hose clamps.

woko
NSW, 1592 posts
21 Jun 2017 9:21PM
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I recon it's a good idea to add an alarm of some sort, with the motor running you can't hear a bilge pump ! If you have a wet sorta bilge then a high water alarm might be the go. The reversing alarms used on trucks and other machines are almost indestructible.


Lazzz
NSW, 885 posts
22 Jun 2017 7:45PM
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woko said..
I recon it's a good idea to add an alarm of some sort, with the motor running you can't hear a bilge pump !



I have a bright LED at the helm & another at the nav station that come on with the main bilge pump.

One day I was washing the anchor chain, as it was coming up, and the water suddenly stopped! I just thought I had blown a fuse or the pump had sh#t itself but the hose had come off at the base of the tap and was pumping sea water into the bilge. I motored for an hour back to my mooring & turned the motor off before I realised what had happened.
The bilge pump kept it at bay but after that I wanted to know if the bilge pump was in use. I now also have a separate float switch hooked up to my Raspberry Pi3 which sets off a nice loud alarm & also sends me an email & text if I'm not there.



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"Bilge Pumps- electric" started by kimtrang