# Small bilge pump to keep it dry.



## zz4gta (Aug 15, 2007)

I'm looking at installing a small bilge pump to keep the boat dry during the week when I'm not around. I like the auto on/off pumps that have a float switch built in. Rule makes one, however, the float switch doesn't come on until the water level reaches 2-3/4" high. Are there any pumps out there that'll switch on around 0.5-1.0" of water depth?


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## JohnRPollard (Mar 26, 2007)

ZZ,

There are some pumps that don't use a float switch, but instead switch on at a set time interval. If they detect water, they cycle until it's gone. If they don't, they shut off immediately.

If this is not your "survival/emergency" pump, I would suggest you go with the smallest size possible and install a check valve in the line (to prevent backwash)..


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## kwaltersmi (Aug 14, 2006)

I just installed a Rule-Mate 750A and have been happy with it so far. It does have internal "solid-state water sensing technology" so a float switch isn't needed. But you're right, the water level does have to be 2.75" before the pump will kick on. So far, the very bottom of my bilge stays wet because of this.


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## klem (Oct 16, 2009)

You will have a lot of trouble getting a bulge pump to actually pump with less water than that. It will difficult to keep the pump from sucking air. When the pump has good suction, it will draw the water down quickly enough that it won't be replenished and will suck air. Once it sucks some air, the water will catch up but then it will have trouble pumping because of having air in the pump. If the pump does get airbound, it will draw down your batteries as it sits there and does nothing.

Do I dare ask why you need to have a pump run on a regular basis? Is there something that is leaking? If it is something like a leaky porthole, it is probably easier and better to fix that.


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## Gene T (May 23, 2006)

Different ways to do this. You can mount a self priming pump with pickup hose to the lowest part of the bilge through a check valve. Use a float switch mounted very low to start it. Or you can just use something like a Rule automatic, they run every 2.5 min to check for water. You can put a check valve on the outlet if you wish, although this is not a good application for them as they tend to stick and these pumps don't have enough pressure to unstick them. I have both types of these pumps. The automatic Rule drove me nuts when trying to sleep on the boat. I use it now to keep my dinghy dry. Works great for that. 

Gene


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## Maine Sail (Jan 6, 2003)

zz4gta said:


> I'm looking at installing a small bilge pump to keep the boat dry during the week when I'm not around. I like the auto on/off pumps that have a float switch built in. Rule makes one, however, the float switch doesn't come on until the water level reaches 2-3/4" high. Are there any pumps out there that'll switch on around 0.5-1.0" of water depth?


I have one... it's called a Turkey baster....


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## L124C (Oct 4, 2007)

I installed a Diaphragm pump (as opposed to the usual Centrifugal Bilge pump) for my maintenance pump. Unlike Centrifugal pumps, Diagram pumps can be run dry without damage (which is why Centrifugal switches don't kick on until the water is 2.5" high), and have check valves built in, so the water doesn't flow back into the bilge. However, they don't pump the volume required for an emergency, so I have a regular bilge pump with a float switch as well. I used a electric switch which senses the water level for the maintenance pump, attached to a ON/OFF switch. This setup keeps the water level in my bilge to about half an inch on Automatic. Unfortunately, my old diesel apparently leaks a small about of oil into the bilge. The oil coats the electronic switch thereby connecting the two sensors. So, unless I wipe off the sensors, it is no longer shuts the pump off automatically. So I use it in manual mode once a week and it still keeps the water level much lower than the float switch would. If you don't have and old diesel that sits midships directly above the bilge, this shouldn't be an issue. I posted a thread here when I installed it if you want to search for it.


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## sailingdog (Mar 19, 2006)

Hey Maine Sail-

How'd you automate the turkey baster??? 


Maine Sail said:


> I have one... it's called a Turkey baster....


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## IslanderGuy (Apr 26, 2008)

Kids 



sailingdog said:


> Hey Maine Sail-
> 
> How'd you automate the turkey baster???


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## L124C (Oct 4, 2007)

IslanderGuy said:


> Kids


A Diaphragm pump is MUCH cheaper!:laugher


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## ukrsindicat (Jul 27, 2010)

Looks like this pump brings the level down to 3/8":

http://www.defender.com/product.jsp?path=-1|51|299222|84462|316440&id=1207040

Yuriy


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## L124C (Oct 4, 2007)

ukrsindicat said:


> Looks like this pump brings the level down to 3/8":
> 
> http://www.defender.com/product.jsp?path=-1|51|299222|84462|316440&id=1207040
> 
> Yuriy


Looks good. However I would definitely go for the optional "non return valve" otherwise, the pump would probably keep cycling. Some frown on check valves for an emergency pumps because of potential clogging, but it looks like a good option for a maintenance pump to keep the bilge dryer.
BTW, regarding my earlier post concerning oil and electronic sensors. I see they have sensors that specifically address this issue now.


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## fcsob (Apr 28, 2007)

I use that pump in my forward bilge with a check valve. It's not my main pump and I service the check valve every couple of months.


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## JohnRPollard (Mar 26, 2007)

fcsob said:


> I use that pump in my forward bilge with a check valve. It's not my main pump and I service the check valve every couple of months.


I agree, check valves are not really an issue if the pump is for bilge maintenance. In fact, if you want to keep the bilge dry, they're almost a necessity.

For emergency de-watering pumps, skip the check valve.


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## L124C (Oct 4, 2007)

The diaphragm pump I referred to earlier in this thread was a Whale, Gulper 220 that cost over $200. It worked fine for about two years, then died due to a leak in the diaphragm. IMO, not great longevity considering the light use it gets. Replaced it with a Flojet 2100-12 I purchased from Grainger for a about $100. Works great, and hopefully it will last longer. If not, it's half the price! It's easy to set up a Grainger account and order on line. They offer some other marine products (i.e., 3M caulking), however the retail prices seemed about the same as West Marine.


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## sawingknots (Feb 24, 2005)

i tend to agree with klem,unless you have a specific leak problem [which should be repaired] i don't see the need for a automatic pump,i also agree with the dog lol turkey baster indeed ,if you have a sudden catastrophic water leak a automatic pump will only delay the inevitable


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## L124C (Oct 4, 2007)

sawingknots said:


> i tend to agree with klem,unless you have a specific leak problem [which should be repaired] i don't see the need for a automatic pump,i also agree with the dog lol turkey baster indeed ,if you have a sudden catastrophic water leak a automatic pump will only delay the inevitable


Well, lets see....It keeps 2 1/2" of bilge water (let in by the packing) from fermenting in the bilge. It also keeps my bilge pump from constantly sautéing in salt water, so that it may work when I need it. Will the Bilge pump save the boat if I hit a whale or a container? Probably not. However, if a valve or hose fails....in combination with the manual pump, possibly.


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## downeast450 (Jan 16, 2008)

I was discussing packing drip with a senior marine engineer friend who has had many boats and has cared for dozens. His suggestion to me for keeping the bilge dry between weekly uses was to drill and tap a grease fitting into the stuffing box, aft of the lock nut. Instead of tightening down on the packing to stop the drip each time you leave the boat you can just pump a little grease in behind the packing. If I am not going to run the engine for a week I tighten the stuffing box and stop the drip. I keep a set of stuffing box wrenches in the engine space for easy access. When I change the shaft log hose coupling next winter I may install a zirk fitting. I am a little uncomfortable about adding a "opening" to the sea if the zirk fitting failed but he assured me he had never had any problems. He cared for some impressive yachts. I also keep an absorbent pad, sometimes just an old towel under the stuffing box to "catch" the small amount of water that collects there. It is easy to remove and wring out the water. A dripless shaft seal is another option.

Down

Down


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## sawingknots (Feb 24, 2005)

L124C said:


> Well, lets see....It keeps 2 1/2" of bilge water (let in by the packing) from fermenting in the bilge. It also keeps my bilge pump from constantly sautéing in salt water, so that it may work when I need it. Will the Bilge pump save the boat if I hit a whale or a container? Probably not. However, if a valve or hose fails....in combination with the manual pump, possibly.


your stuffing box shouldn't be leaking to the extent of actually accumilating in the bilge,that small amount should evaperate,unless you have another leak,i've personally saw 2 boats sink due to hose failure and both owners said they had automatic bilge pumps,try opening a thu hull and see how long your bilge pump keeps ahead of that leak,and how long before your battery are drained,i also 2 older wooden boats sink that had constant [owners aware]water leaks one of which had 3 automatic pumps


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## RobGallagher (Aug 22, 2001)

After a near sinking off Block Island a couple of weeks ago I am adding a second bilge pump.

I have one "medium" sized pump under my mast step in the deepest part of the bilge. It could not keep up with a torn stuffing box hose. That is not a good feeling.

I do have a manual pump in the cockpit... Useless as nothing but a last resort. I never thought this before, but, with experience it has become clear that a manual pump is the thing you use when you are sitting in the cockpit waiting for help to arrive.

If you doubt me, try sailing your boat, talking on the cell phone to the CG, answering (warding off the salespeople might be a better description) the tow boat companies on the VHF, and attempting to patch a leak. Now do all this while pumping by hand.

A large capacity back up pump (electric) can buy you precious time while you follow protocol and, if possible, remain self sufficient.


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