[C320-list] Bilge Pump Makers? Comments? Experiences?

[Danny Jensen]

Steven,
I'm interested in using a relay connection to run my primary pump off my alarm float switch per your design. Where did you get your relay?

Good idea about having a hot spare auto sensing pump. Do you have the part number for the primary Johnson pump?

Sent from my iPhone

> On Jun 30, 2017, at 6:17 PM, Stephen Cox <scox at timmin.com> wrote:
> 
> My MkII came with it's bilge pump fitted in the bilge itself.  It ultimately
> failed with a small wood chip from the build process jamming the impellor.
> I subsequently installed a much larger Johnston pump.  
> 
> However, there was enough water collected in the bilge at one stage to
> trigger the pumping process but not enough to really pump the bilge right
> out. So with the back flow of what's left in the delivery tube the setup got
> into a start stop repeat cycle.  Inevitably before I could fine tune the
> shaft packing gland correctly, this repeat cycle happened while I was away
> for some weeks.  The nett result was that the bearings in that Johnston pump
> suffered somewhat from being continually run in a partially dry environment
> and are now very noisy.  
> 
> I don't believe putting a check valve in is the answer as the ones supplied
> with most pumps I have seen are just rubber flaps that will not seal
> effectively over the longer term. At best they would just slow the cycling
> process down, not eliminate it.  Any more substantial "proper" check valve
> will impede the flow of water obtainable because of the pressure needed to
> overcome the valve mechanism, hardly a desirable outcome if taking on
> serious water.
> 
> I have now fitted a pump to the front bilge compartment of the same size as
> that originally fitted but with automatic sensing involving the pump
> spinning up briefly every little while and sensing the load.  If there is a
> load it continues spinning until all the water has gone and the load
> decreases.  Yes there is still a back flow but it is smaller.  It is still
> possible to get just the right amount of water in the bilge to cause a cycle
> pattern to occur but because of the sensing process this is at least
> periodic rather than continuous.
> 
> I have also replaced the larger Johnston pump with a new one, fitted in the
> rear bilge compartment, with a separate larger disposal hose to the rear of
> the boat. This new one is set up with two float sensors and some latching
> relays to cause a significant water level differential between pump on and
> pump off.  So no cycling occurs unless there is a real need. i.e. continuous
> ingress of water.  The sensors are set to only fire when the water level is
> well above the trigger point for the smaller pump, so it is an emergency
> rather than a day to day bilge pump.  An alarm also sounds when this pump
> runs.  Both pumps are independently fused.  I have the disposal hose outlet
> to the side of the rear step, spraying out over the ladder lid, to easily
> see if it is pumping and how solidly.
> 
> Further refinements have been:
> 
> 1. Purchase a second identical automatic sensing pump as a spare and I have
> also kept the noisy larger pump as a spare..
> 2. Fit waterproof plugs and sockets to both pumps' electrical leads and
> screw connections on the hoses.  This means if I have a pump problem at sea
> I can quickly replace the pump.  Trying to make jury rig electrical
> connections or get hose clips and hoses apart in a heavy sea is not a
> realistic proposition in my opinion.
> 3. I have fitted a completely separate water level sensor at a fairly high
> level to catch the situation when both pumps for whatever reason don't
> appear to have worked.  This sensor drives another bilge alarm and two
> independently fused relays connected to the two bilge pumps.  This covers
> the situation where the normal sensors have failed and serious water is
> coming in and will ensure that if one pump has also failed at least the
> other one will be kicked off.
> 
> This all sounds a bit belts and braces but does bring peace of mind,
> particularly if sailing single handed or with inexperienced passengers
> rather than crew.
> 
> I don't think we will ever solve the cycling problem without being OK about
> having some water in the bilges.  I try to keep mine dry as an easy way of
> checking for water ingress.
> 
> 
> 
> Stephen Cox   
> Tegwen #1141
>