How many bilge pumps?

[Startracker]

Originally Posted by MicHughV

Some of the posters here bring up a good point...which is battery location.

Obviously, due to their weight, the ideal location is low and central, but too low also puts them within reach of water ingress.

Once water reaches the battery terminal's, you will have a problem.

Many boats have batteries connected together, so when one goes, they all go.

Battery location requires some serious thought.

Exactly. It's why as much as I like the low/center location for my batteries, they're moving. How many people bother to multiply out the cubic footage of the boat? The bilge volume is amazingly low. Under a settee I get many cubic feet of water before anything is permanently wrecked. Under the floor, the batteries could be gone before I notice the water, and it would only take a couple minutes of a thru hull without pumps to fill that far. My boat is my only valuable asset.
1000$ to cover most of the eventualities which could cost me that asset is cheap insurance. On much more expensive boats like OPs, I think it's crazy not to invest in pumps. I've seen 1M$+ boats with less capacity than any one thru-hull. I guess if you have good insurance it doesn't matter so much.

[AKA-None]

Please don’t use your pump switch as your bilge alarm switch.

[GordMay]

Originally Posted by TrentePieds

...
There are some other issues you might like to think about: IMO a 4K gph bilge pump is TOTAL overkill in your boat, but the wiring will be the same regardless of pump capacity, so why don't we start with the wiring?
Cultivez la simplicité :-)!
TrentePieds

The argument can be made, that the smaller the boat, the larger the recommended bilge pump; because the same leak [inflow] will sink the smaller boat, faster than it will a large one.

For emergency use, fit the largest pump practically possible.

For every day nuisance water clearance, fit the smallest self-priming diaphragm pump available [less backflow when it stops].

I'd also keep the high-volume manual pump [cockpit mtd], since all that pumping capacity will be useless, if something happens to your electrics.

FWIW: The American Bureau of Shipping [ABS] recommends one 24-gallon-per-minute (gpm) pump [about 1,440 GPH], and one 12-gpm [720 GPH] pump for boats under 65 feet.
ABYC is silent on bilge pump capacities.

[gwoiler]

Originally Posted by Startracker

Useful more often than you'd think.

OK. Coming up to speed here. My last question is about 2 cycle versus 4 cycle trash pumps. I was thinking, if it gets used very little, a 2 cycle is smaller. Even though most people think you can not store gasoline for a long time... you can. the trick is twofold. You have to store non-alcohol gas, and you have to store it in a pressure proof container. If it can't vapor off, it will never varnish. If it is out of the sun, it is easy to store if the container seals up and can withstand a little internal pressure. I have stored unleaded gas in 55 gal drums many years, and when cracked open, it was just as fresh as the day I filled them. If in doubt, a little gas preservative can be added.


So, what say you? 2 cycle, or 4 cycle on the trash pump? Yeah... if you are lending it out all the time, 4 cycle would be safer seeing how people can do dumb things and run it without the oil.


Also.... Over time, I have seen a few tiny generators that were 2 cycle, and not a whole lot of watts - maybe 500? Don't remember. But the thing was so tiny. I always wondered if that was something worth having just in case?

[Startracker]

Originally Posted by gwoiler

OK. Coming up to speed here. My last question is about 2 cycle versus 4 cycle trash pumps. I was thinking, if it gets used very little, a 2 cycle is smaller. Even though most people think you can not store gasoline for a long time... you can. the trick is twofold. You have to store non-alcohol gas, and you have to store it in a pressure proof container. If it can't vapor off, it will never varnish. If it is out of the sun, it is easy to store if the container seals up and can withstand a little internal pressure. I have stored unleaded gas in 55 gal drums many years, and when cracked open, it was just as fresh as the day I filled them. If in doubt, a little gas preservative can be added.


So, what say you? 2 cycle, or 4 cycle on the trash pump? Yeah... if you are lending it out all the time, 4 cycle would be safer seeing how people can do dumb things and run it without the oil.


Also.... Over time, I have seen a few tiny generators that were 2 cycle, and not a whole lot of watts - maybe 500? Don't remember. But the thing was so tiny. I always wondered if that was something worth having just in case?

2 Stroke all the way!! Epecially for units that are being lent/rented out.
Yes gas preservation isn't rocket science. I always go a little overboard with stabilizer though.
The reason is a 4 stroke is susceptible to insufficient oil, either by user error, during unloading/loading and not so happy being crammed into lockers sideways after draining the gas and running the carb dry. 2 strokes never run low on oil.
2 Stroke is lighter too. I don't care how loud it is, unlike a generator.

That being said, when rented it came with enough already mixed by me gas, in a 5 gallon jerry can labeled for it specifically, with dire warnings about the consequences of using gas from another can. This also prevented filthy gas being used, a more common problem.

[geoleo]

Originally Posted by gwoiler

My boat is 3.5 hours away from me [Indiantown]. I have spent less than 8 hours on it since buying it last May. Mother duty is priority. Each time I get an hour or more, I keep busy. Rotten scupper drain hoses were letting rain water inside - Fixed. Rain water coming in at the mast - need to fix. Mold - cleaned up. Filthy bilge - needs cleaned. Bilge pump switches and wires need sorted and understood.

Every boat is different and then, how did the previous owner make changes? I ask questions to get a better idea how ans where I should be looking. At the moment, getting ready to install a dehumidifier that runs off the solar panels to help keep mold down. So yes... If an answered question or idea given helps me zero in on a fix... I am all ears. And, your comment was good also. Thank you.

Have had 7 sailboats in past 50 years in Florida. Best thing for mold is MOLD AWAY from Home Depot. $10qt.After cleaning just leave a thin film of it on surfaces-works wonders.

[sailingharry]

I ponder the usefulness of large bilge pumps.

I have read multiple stories as well as heard first-hand accounts of boats that have sunk where it took many hours to sink and it happened in relatively calm weather -- not crazy survival type conditions. I can't help but think that in those situations the ability to move massive amounts of water would have saved the day.

The problem is that there are no 12 volt pumps that meet this need. Water takes power to move, and few bilge pumps are rated at more than a couple of hundred watts (the most powerful one on Defender is rated at 15 amps or 180 watts) Engine mounted pumps are certainly an alternative, but very expensive and difficult to do -- which probably explains why a very small percentage of boats have them.

I believe the answer is a 1 horsepower residential sump pump. 1 horsepower is about 800 watts or a 70 amp drain on the batteries -- four times the biggest pump on Defender. A lot of power (and a lot of water)! But they are fairly small, fairly portable, and will easily run off of any inverter typically installed on cruising boats. This could be installed in a somewhat permanent fashion, or simply stored in a locker and deployed when needed.

I know it relies on an inverter. And that might fail. But wow, if it doesn't fail, it will empty the water out of your boat! For an investment of around $100. And if it does fail, you still have what you had before you tried it! Lol

We are doing the Down East Circle this coming summer and I think this will be at least in a locker where it could be pulled out and fired up in 10 or 15 minutes or less.

[GordMay]

... I believe the answer is a 1 horsepower residential sump pump. 1 horsepower is about 800 watts or a 70 amp drain on the batteries -- four times the biggest pump on Defender. A lot of power (and a lot of water)! But they are fairly small, fairly portable, and will easily run off of any inverter typically installed on cruising boats. This could be installed in a somewhat permanent fashion, or simply stored in a locker and deployed when needed...

A typical 1 HP domestic sump pump will weigh over 20 pounds, and measure about 10" in diameter [<12" high], and draw about 9 - 10 Amps [running, FLA] @ 120VAC [± 100A @ 12VDC].
It might pump ± 5,500 - 6,000 GPH @ 5 Ft head [5,000 GPH @ 10'], through an 1-1/2" smooth bore discharge hose.

[moseriw]

A typical 1 HP domestic sump pump will weigh over 20 pounds, and measure about 10" in diameter [<12" high], and draw about 9 - 10 Amps [running, FLA] @ 120VAC [± 100A @ 12VDC].

No way with a whale 4000 Gph you are with 25A at 12VDC and if the pump lasts it out you are done at 8-10 hrs with your battery capacity. Yes OK we charge too...

Just wanted to mention that those pumps need energy and it has to come from somewhere.

So maybe 3" a gas-pump for around 400 USD (Kärcher) and a capacity of 10.000 Gph would be a good choice for emergency. The downside: 36 kgs 60x40x40 cm, 5 kW / 1,5l/hr and you need the hoses of the fire brigades.

[rslifkin]

Originally Posted by moseriw

A typical 1 HP domestic sump pump will weigh over 20 pounds, and measure about 10" in diameter [<12" high], and draw about 9 - 10 Amps [running, FLA] @ 120VAC [± 100A @ 12VDC].

No way with a whale 4000 Gph you are with 25A at 12VDC and if the pump lasts it out you are done at 8-10 hrs with your battery capacity. Yes OK we charge too...

Just wanted to mention that those pumps need energy and it has to come from somewhere.

So maybe 3" a gas-pump for around 400 USD (Kärcher) and a capacity of 10.000 Gph would be a good choice for emergency. The downside: 36 kgs 60x40x40 cm, 5 kW / 1,5l/hr and you need the hoses of the fire brigades.

This is a good point. Whether or not really large electric pumps are a viable option depends on the electrical systems of the boat in question. If you've got big batteries, an inverter, and a generator that is mounted high enough, you can power a lot. But if you don't have those options, then you can't do nearly as much with electric pumps and may want to consider a gas powered one (with associated storage and maintenance concerns).

[MicHughV]

I remember an article some years ago done by "Cruising World".....at least I think it was "Cruising World" magazine, whereby a number of bilge pumps were tested to see, if, in fact, they could pump their rated gpm.

All pumps tested fell far short of their claimed production in real life scenario's.

One must remember that the "claimed" gpm amount is likely under laboratory control, but in real life, the bilge water must travel from the bilge "upwards" and along a relatively narrow tube which is likely quite long with any number of curves, kinks, etc, in it, all of which is robbing the system with friction and other pipe losses..

Additionally, the voltage source for these pumps soon fall off, which means the pump is not operating under it's full capacity.

Most pump discharge lines are typically 1 1/2" inside dia. which is not very large to move a lot of water.

Taken altogether, I seem to recall that, eg, a 1,500 gpm pump is likely to only do about 50% of it's rated capacity under the best of conditions and even then only for a limited time.

[Startracker]

Originally Posted by sailingharry

I ponder the usefulness of large bilge pumps.

I have read multiple stories as well as heard first-hand accounts of boats that have sunk where it took many hours to sink and it happened in relatively calm weather -- not crazy survival type conditions. I can't help but think that in those situations the ability to move massive amounts of water would have saved the day.

The problem is that there are no 12 volt pumps that meet this need. Water takes power to move, and few bilge pumps are rated at more than a couple of hundred watts (the most powerful one on Defender is rated at 15 amps or 180 watts) Engine mounted pumps are certainly an alternative, but very expensive and difficult to do -- which probably explains why a very small percentage of boats have them.

I believe the answer is a 1 horsepower residential sump pump. 1 horsepower is about 800 watts or a 70 amp drain on the batteries -- four times the biggest pump on Defender. A lot of power (and a lot of water)! But they are fairly small, fairly portable, and will easily run off of any inverter typically installed on cruising boats. This could be installed in a somewhat permanent fashion, or simply stored in a locker and deployed when needed.

I know it relies on an inverter. And that might fail. But wow, if it doesn't fail, it will empty the water out of your boat! For an investment of around $100. And if it does fail, you still have what you had before you tried it! Lol

We are doing the Down East Circle this coming summer and I think this will be at least in a locker where it could be pulled out and fired up in 10 or 15 minutes or less.

I chuck a sump pump in at the dock, connected to shore power. Own float, own power source, unlimited power available generally. takes the wear and tear on a cheaper pump. Works great.
For cruising, gas power is where it's at. Trash pumps are far better than sump. And the secondary uses are very handy, so far rescuing a few boats including getting a beached one un-beached. It's even eaten plastic bags, god knows how many pounds of sand.

Doesn't even have to be massive flow rates,look at that lovely steel boat, I forget the name now, that sank after being swamped in bad weather. Couple had lots of cruising time, in the end they lost their home due to books and debris clogging the pump.
To my mind most boats are massively underprotected from the single most likely to cause loss issue. Water is patient, it has from the day the boat is made to the day it is scrapped or sunk to win.

the cost differential between a 800 watt sump pump and a 2200 GPH 12v marine pump is not enough for me to rely on the sump pump underway.
I just look around the boat, what's the biggest thing that is likely to fail in a single event, barring catastrophic collision in which case no pump is going to save you. On my boat that is a 1-1/2" hole. Bigger boat, bigger holes. Run the numbers, add enough pumps to cover that and some reserve capacity. Do that and you're more protected than most commercial boats in the same size range.

[MicHughV]

based on my own personal experience....a scared sailor with a bucket in his hand is likely the best bilge pump you can have when the chips are down...

[Startracker]

Originally Posted by MicHughV

based on my own personal experience....a scared sailor with a bucket in his hand is likely the best bilge pump you can have when the chips are down...

I think that is largely an old wives tale, or people are running dodgy undersized pumps.

That assumes:
1. The sailor can fit the bucket into the space where the water is, I don't really want to wait until water is a foot over the floor to get a decent sized bucket in there.
2. The sailor doesn't have other things to do, like fixing the problem to stop the water, provide medical care to other crew, or be at the helm to try and get it on a beach.
3. Where the water is is a nice straight shot out of the boat, and the height to where you can chuck it is low.

Ignoring for the moment the option of a gas powered trash pump, lets go with just electric and a normal manual bilge pump at the helm.
2200 GPH emergency pump and a single 750 GPH scavenger, whale gulper at 1500 GPH if you're really whaling on it, but lets say you can only pump it half the time because you're also steering so we'll call that 750 as well.

That gives your scared bucket with a sailor the following: 1 second to fully fill the 5 gallon bucket, right to the rim with not a milimeter of space left. 2.1 seconds to carry the bucket and throw the water up and out of the cabin. They must do this every 3.1 seconds without fail. Each of those buckets weighs 41 lbs.
If you can throw the equivalent to a full bag of concrete from your feet, up and over onto something around or above your shoulders every 3.1 seconds, then you'll just about keep up with the pumps. Until you get tired or have to do something else.

Personally I'd rather have a scared sailor yanking the manual pump and steering, or figuring out how to stop the leak and letting the electrics handle the water.

[GordMay]

Originally Posted by MicHughV

based on my own personal experience....a scared sailor with a bucket in his hand is likely the best bilge pump you can have when the chips are down...

Originally Posted by Startracker

I think that is largely absolutely an old wives tale ...

Indeed.
May be closer to the truth, in a small open boat [dinghy].