last bit of water from the bilge

[scosch]

My CD30 has a deep bilge with about a 3-4 foot rise from the bilge pump to the outlet in the transom (plus another 6 inches for the anit siphon loop). So it seems that I never really get a dry bilge and always have ummm... maybe 1/2 inch of water in the 8" x 20" area down there after pumping and then a little more after the check valve slowly leaks its load back. Anybody got any tricks for removing the last bit of water other than a sponge and bucket. Dont really want to do that every few days. The reason I ask is because I read some quote (maybe this site) that, and Im paraphrasing," absolutely nothing good has every come of having any water in the bilge." Maybe I should just be happy that I dont have any real leaks and when in the marina the pump runs maybe only once every few days for a few seconds.

[teshannon]

I have a bilge with about the same depth and always have an inch or so of water in it. It's just impossible to pump the last inch out. I just leave it there and it poses no problem, I would not be concerned.

[JohnRPollard]

Usually you wouldn't want a check valve in your primary bilge pumps. They are somewhat prone to failure/blockage, which can be very problematic in an emergency dewatering situation.

What some folks do is install a second, very low volume bilge pump, with a check valve immediately after the outflow exit. This pump, equipped with the check valve, can handle the little trickle amounts that end up in the bilge during the course of normal operations. And the check valve prevents most of the backflow from returning to the bilge when the pump shuts down.

It works best at keeping a bilge nearly completely dry if there is a small sump at the bottom of the bilge, where the last bits of water collect. Even without that small sump, it works better for drying the bilge than the high volume pumps, because they use small diameter hose that will not begin sucking air nearly so soon.

If you want to then take it another step further, you can raise your primary dewatering pump(s) up a bit off the bottom of the bilge. This way, they aren't constantly getting wet. And they should not have check valves!

[scosch]

If one has two bilge pumps, a high volumn one that wouldnt have a check valve and a daily use smaller one that does have a valve, can the two drain hoses be Tee'd together somewhere to use the same thru hull? I guess they cant be teed until close to the thru hull and after the siphon loop or the water would drain back thru the check valveless pump.

[GBurton]

Just use a shopvac to suck up the last little bit. Its great to have a dusty bilge

[sailingdog]

You generally don't want to have two bilge pumps hooked up to the same through-hull.

JRP's suggestion is a good one, where the small pump is considered a "maintenance" pump, and the larger one, with the high volume is a dewatering pump. Ideally, the larger pump should have a float switch located a few inches above the maintenance pump one and have a high-water alarm connect to the switch as well.

[timebandit]

How about something like this--
Sig 12V Electric Fuel Pump Gas/Glow
Conected to a sink drain?

Rick

[noelex77]

With a good dripless shaftseal a totally dry bilge is easy to maintain. It also makes any fluid leak (oil, diesel and fresh and salt water) very obvious.

[sander06]

Use a shop-vac for the last few drops.

[jackytdunaway]

i keep a paper towel under my packing nut and it catches the water so my bilge is always dry. if i do see water in my bilge i assume a i have an issue and wrok to find it. One time it let me to an anti-syphon gone bad and another time to my presure valve on the water heater. A normally dry bilge that has water in it is the canary in the mine. A keel stepped mast will make this a little harder though