Cal 2-29 Bilge pump cycling

[nylajo]

Due to the depth of the bilge that rums down the back of the keel, anyone have any suggestions how to stop bilge pump cycling, I have tried NR Valve but the bilge water always seems to leak back int to the bilge causing the bilge pump to cycle.

[capt jgw]

I had a similar problem in my Columbia 36. One large bilge pump amidships with about 20 feet of 1 1/2" hose discharging out the transom. The hose contained enough water to cycle the pump when it drained back to the bilge and it would pump that same gallon or two of water back and forth all day long. My solution was to remove the big pump and replace it with a little one, 360gph as I recall, with as short a hose run as possible discharging amidships at the gunnel. Only a few ounces drain back, not enough to cycle the pump. The big pump with it's own float switch was put back in on a shelf about 4" above the little one. The little pump handled nuisance water and the big one was still there in case of more serious flooding, which never happened. An alarm on the big one would have been a good idea but I never got around to it.

[TrentePieds]

Let's see what we can do to help you out here :-)!

Is this the boat you have?

https://sailboatdata.com/sailboat/cal-2-29/

If so, please explain what you mean by "the bilge that runs down the back of the keel".

The canoe body of this boat is quite shallow and the pickup point for the bilge pump would be just about in line with the forrard edge of the dinette table.

What's the make and model of you bilge pump?

TrentePieds

[Don C L]

Originally Posted by TrentePieds

If so, please explain what you mean by "the bilge that runs down the back of the keel".

Encapsulated keel with lead ballast in the forward 2/3 or so I believe.

[TrentePieds]

You mean that the after 1/3 of the fin keel is hollow????

Technically feasible, but obviously daft!

Or did I misunderstand you?

TP

[Don C L]

Its construction is similar to the Cal 28:
https://sailboatdata.com/sailboat/cal-28/

[nylajo]

Correct, the aft part of the encapsulated keel contains the bilge which is about 30” deep and about 3”x 7” at the bottom, therefore when the bilge pump is at the bottom the bilge hose contains more water than the float switch swing travel and when the float switch drops all the water runs back ant the pumps just cycles on and off every few seconds. I have tried a check valve but they don’t seal well enough.

[capt jgw]

The key is the length of the hose. If it runs all the way to the stern like mine did that's a lot of water. Just shortening it and moving the discharge point closer to the pump may cure the problem. It does have to run all the way up to the sheerline though, not just above the waterline.

[nylajo]

The 5/8” hose from the pump to above the waterline still holds more the the bottom of the bilge

[leecea]

I wonder of the float switch can be adjusted or something like that. We recently had one episode of this cycling after I'd drained the hot water heater into the bilge for winterization. It's never happened before.

I used the manual switch to run the bilge pump and it pumped out enough water to stop the cycling. It seems like the float switch was turning the pump off too early.

[nylajo]

I am wondering if I put a vented loop in the bilge hose if that would work.

[nylajo]

If this is a stupid idea don’t be too harsh with me as I am desperate, I have to visit my boat every day until I cure this.

[Don C L]

Is there some kind of steady leak going on? How about just drying out the bilge using a hand pump?

[TrentePieds]

Unless I've got my math wrong, given those dimensions, the amount of water in that bilge will amount to roughly 1 liter per inch of depth, I believe.

5/8 hose has a cross-sectional area of the bore of about 2 cm^2. 30" = 75 cm (approx). This 30" of 5/8 bore hose will hold (75 x 2) = 150 cm^3 of water which equates to 0.15 litres of water.

Just set the float switch/pump on a bit of a block. Such a smidge of water will never bother you when confined in such a tall narrow vessel. The well is probably not gel-coated on the inside, so you might like to wipe it dry, let it air-dry and get some paint on it to render the surface impervious to water.

But check my math :-)!

TP

[nylajo]

Originally Posted by Don C L

Is there some kind of steady leak going on? How about just drying out the bilge using a hand pump?

I live on Vancouver Island it rains quite a lot here.