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Sailingchefs 04-13-2010 03:11 PM

Bilge Pump Installation
Hi all,

Trying to update the boat with an electric pump. After doing some research, I'm looking for some experiences with this job.
I decided to go with the Rule 2000, with it's own thru-hull, in addition to my soon to be rebuilt manual pump.This should give me, all things considered, about 1700-1800 real gallons per hour, plus a manual piston pump.
Here are some of my concerns, in no particular order:

-Suppose I wanted to be even more OCD, and install a smaller Rule 500 Fully Auto. (that I already have a couple of) in a slightly lower position in the bilge as the ( bilge pump page suggests. Does that necessitate yet another thru-hull, or some ingenious combination of Y's and anti-backflow devices? It does seem less of an issue than with tapping into the manual pump's hose, since the smaller, lower one would also be running and largely irrelevant if the 2000 needs to kick in. Sonnet II will be on a mooring for the summer, and although I usually get out once or twice a week, I have no good way to recharge the batteries without running the motor. (Only a tiny cheap solar panel, and no new one in the budget.) I like the idea of the tiny low-draw pump taking care of small amounts of rain water while I'm not around without killing the batteries. As everyone says, its likely to stay dry and never be an issue anyhow. Just a bit of mental comfort and extra redundency for two sailors who took turns working a 3ft. man. piston pump for 2 1/2 hours non-stop, literally for our lives,one evening last fall.

-One of the tech guys I spoke to today explained to me that the anti-siphon loop was the point in the new pump's discharge hose that the water would drain back into the bilge from when the pump shut off, possibly turning it back on. I had thought to put said loop just forward of and higher than the new thru-hull, but that leaves the maximum length of hose to drain back into the bilge. Tech guy suggested I put the loop as far forward, close to the pump, as possible. I know all the different years and models have different bilge layouts, but does any one have a strong position on the best route for the new discharge hose and placement of the loop considering this back flow issue? Maybe it's high up just forward of the manual pump in the laz.? (In a 1984 Catalina 25)

-And about this vent in the loop; what is it called, and who has them?
Why do they get blocked, as they apparently do?

-The DPO seems to have added 3-4 ft. of smaller diameter clear vinyl hose, through a Home Depot reducer, to the end of the manual pump's pick-up hose. It does a loop back aft so the cut end rests on the floor of the bilge. Could this have been intended to prevent back flow from the manual pump? Doesn't seem like it would.
The larger, original black hose lays flat on the floor of the bilge, but from my reading, it seems it at least needs a strainer installed on the end. Agreed?

-Every one refers to the manual pump's thru-hull as being 6 inches above the waterline. As it happens, the center of my thru-hull is 3 1/2 inches above the waterline, and mine looks like all the others.
Since the top of the keel/ bottom of the bilge is not quite 2 ft. below the thru-hull, I'm thinking putting the new hole a few inches higher on the transom wouldn't be so bad. It sounded like it was placed lower not just for less static head, but to minimize splash/staining on the hull. Since this pump should never turn on anyway, not an issue right?

-For the wiring, I'll probably go with the Rule 3-way switch; wire it directly to the panel with no breaker, and mount the connections in the bilge as high as possible with shrink connectors and a dab of dielectric grease.

-Since our current Honda outboard motor is a pull start with a generator, I'm looking at going with 2 of the largest marine deep-cycle batteries that will fit in the battery locker. I have yet to measure this up. Anyone care to chime in on their favorites or what the max. size that will fit is?

Thanks, Glenn

Architeuthis 04-13-2010 04:10 PM

I looked at some of these issues and decided the following:

Each bilge pump gets its own thruhull.

Each pump gets its own hose with a clean a shot to the thruhull as practiable.

Only one has an anti-syphon which I left in place as it has not caused any trouble, one has a high loop to prevent water from entering unless boat is well underwater, in which case pump is likely running.

Bilge area is large enough to not have pumps restart after pumping water so don't know about that for your boat.

If you are going to share hoses and thruhulls, I would use a Y valve and a simple on/off for the large pump. Idea being that the large one is just for another incident in which much manual pumping is needed. Look at your boat maybe this does not need a thruhull at all. Maybe you have a way of just leaving the hose coiled and ready to be fed though something to get it over board? Something to consider if another thruhull is not an option and you want that back up.

Better or same diff to leave the small one on when you are not at the boat. Not that it will use much less power, the amount of water leakage determines that but it will operate a little longer when your battery is dying. Big pumps draw big current.

Edit: You might want to consider keeping only one battery on the boat and replace it with the other one (fully charged of course) when you do your regular inspections. This will also get you to check voltages regularly and give you an idea how long you can ignore, I mean, extend the periods between inspections. When you go away for a long time leave both fully charged in the boat. AGMs are great for this work as they do not selfdischarge much and are easier to carry around.

sailingdog 04-13-2010 05:08 PM

I've written about bilge pump installations on my blog and suggest you read it.

In general, each bilge pump should have a dedicated through-hull. The output hoses should be looped to at least 1' above the waterline and have an anti-siphon device installed in them.

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