Bilge hoses, check valves, and smell

Nov 16, 2012
1,037
Catalina 310, 2000, #31 31 Santa Cruz
Our C310 has a 3/4" bilge hose on an electric pump with a check valve and strainer (no idea who installed that or why!!). There's also a 1-1/8" hose with a flapper valve at the inlet going to the Whale manual pump. Recently we spent an afternoon cleaning the bilge, removing all the water, and ended up with a nice, clean, dry bilge. I'm now discovering that the water left in the two hoses is going anoxic/septic and, not surprising, slowly leaking back into the bilge. So now not only does the bilge not stay dry, it stinks worse than before.

My plan now is to remove the check valves and strainer, replace both hoses (nice smooth inside walls), clean the bilge (again), and then manually sponge out the water that drains back from the hoses when we're finished. Assuming that neither pump is needed, that should solve the problem, I think. Does that seem reasonable? Other thoughts?

I know some of you have gone to a larger pump, but I don't see how to get two 1-1/8" hoses (one for the Whale manual and one for a big electric) run, plus two pumps in the bilge; other than mounting a big (diaphram) pump externally and then somehow routing that hose back to the stern.
 
Dec 2, 1997
8,709
- - LIttle Rock
Removing the check valve and strainer (never a good idea in a bilge pump line) and new smooth hoses are exactly what I'd have recommended...along with removing any run back water ( I used a dinghy bailer, bucket and a BIG sponge) before the boat will sit each time. Also useful to leave hatches to the bilge(s) open when leaving the boat to allow air to help the bilge dry out completely.
 
Nov 16, 2012
1,037
Catalina 310, 2000, #31 31 Santa Cruz
Removing the check valve and strainer (never a good idea in a bilge pump line) and new smooth hoses are exactly what I'd have recommended...along with removing any run back water ( I used a dinghy bailer, bucket and a BIG sponge) before the boat will sit each time. Also useful to leave hatches to the bilge(s) open when leaving the boat to allow air to help the bilge dry out completely.
Thanks, Peggy. The strainer puzzled me. I could see putting it on the intake, but why the outlet?
 
Feb 26, 2004
22,760
Catalina 34 224 Maple Bay, BC, Canada
Rob, could be the lack of knowledge (kindly) of the PO. Hope you're enjoying your new boat. And that you haven't found too many of these fusterclucks elsewhere. :)
 
Nov 16, 2012
1,037
Catalina 310, 2000, #31 31 Santa Cruz
Removing the check valve and strainer (never a good idea in a bilge pump line) and new smooth hoses are exactly what I'd have recommended...along with removing any run back water ( I used a dinghy bailer, bucket and a BIG sponge) before the boat will sit each time. Also useful to leave hatches to the bilge(s) open when leaving the boat to allow air to help the bilge dry out completely.
Peggie, there seem to be quite a few different bilge hoses out there (144, 147, 149, 141, 148, 140). Any that you recommend, or not? Some say not for use below the water line, or for a thru hull below the water line. In this application it's not really "below the water line", but is that something I should avoid?
 
Nov 16, 2012
1,037
Catalina 310, 2000, #31 31 Santa Cruz
Rob, could be the lack of knowledge (kindly) of the PO. Hope you're enjoying your new boat. And that you haven't found too many of these fusterclucks elsewhere. :)
Thanks. Loving the boat. I'm really glad we started with a C27, because it was a nice, inexpensive introduction and taught us a lot about what we wanted. So far the C310 has been great for us.
 
Dec 2, 1997
8,709
- - LIttle Rock
Peggie, there seem to be quite a few different bilge hoses out there (144, 147, 149, 141, 148, 140). Any that you recommend, or not? Some say not for use below the water line, or for a thru hull below the water line. In this application it's not really "below the water line", but is that something I should avoid?
Welll...one could make the case that your bilge pump will be "below waterline" if the bilge floods. Because it's hard to go wrong erring on the side of caution, I'd avoid any that aren't rated for below waterline use. And I'd choose smooth walled hoses, not corrugated. #148 seems to be a safe bet but you may prefer a black hose, if for no other reason to distinguish it from your sanitation and water hoses. Make it long enough to put a high arch in it that's well above the thru-hull.
 
Nov 16, 2012
1,037
Catalina 310, 2000, #31 31 Santa Cruz
Well, this has suddenly gotten more complicated. A closer look today revealed that I've actually got a Rule 1100 pump, with a 1-1/8" outlet, but there are several fittings that reduce it to 3/4" which is size of the hose running to the thru hull (it actually tees in between the Whale manual pump outlet and the thru hull on the C310). The way the hose runs there's no way (at least for me) to replace it with anything larger. It also turns out the pump is a little flaky, so here's my question: since I need to stick with 3/4" hose for the electric bilge pump should I go with a new pump with 3/4" outlet, or stay with a new, larger pump with a reducing fitting?

I realize the bigger pump won't be able to run at rated capacity with the reduced hose size, but maybe it will still do better than a smaller pump. Or will the extra resistance cause the pump to die an early death (maybe that's what happened already)?

Sure glad I looked more closely before ordering the new hose! What's that about measure twice and cut once?
 
Dec 2, 1997
8,709
- - LIttle Rock
so here's my question: since I need to stick with 3/4" hose for the electric bilge pump should I go with a new pump with 3/4" outlet, or stay with a new, larger pump with a reducing fitting?
Hose size depends on the size of the pump (GPH + gallons per hour):
Rule Mate Pumps 12 Volt DC Automatic Bilge Pump Data
Model GPH Hose Diameter
RM500A 500 3/4"
RM750A 750 3/4"
RM1100A 1100 1-1/8"
So I'd go with the hose size that matches your pump.
 
Nov 16, 2012
1,037
Catalina 310, 2000, #31 31 Santa Cruz
Hose size depends on the size of the pump (GPH + gallons per hour):
Rule Mate Pumps 12 Volt DC Automatic Bilge Pump Data
Model GPH Hose Diameter
RM500A 500 3/4"
RM750A 750 3/4"
RM1100A 1100 1-1/8"
So I'd go with the hose size that matches your pump.
In this case the hose size is fixed at 3/4". In that case do I go with the pump size that matches my hose? Or can I stay with the larger pump, with a reducer, like it already has?
 
Nov 16, 2012
1,037
Catalina 310, 2000, #31 31 Santa Cruz
Marchem, At 80 psi your 3/4 hose can discharge about 12 gal per minute (see chart)
http://www.engineeringtoolbox.com/water-discharge-hose-d_1524.html
It becomes a decision of psi ability of pump, discharge rate of hose, volume of water, and boat bucks.
I guess my real question is if a bigger pump would have more pressure and more flow, since it would require lots of boat bucks to install a larger hose. It also seems that the smaller hose would have the same affect as a higher head for the pump to work against, I think.