Bilge Pumps

[Stemar]

The pumps in Jazzcat (one per hull) are inadequate, taking far too long to clear the results of a leak from the exhausts. They're diaphragm pumps of unknown make, about 3 1/2" in diameter and about 8-10" long and are getting a bit long in the tooth (38 years), so I'm considering replacing them, though if you can convince me that a refurbishment will be my best option, that's the way I'd go.. Both they and their filters are also hard to get at, so re-siting them might be logical.

What would you put in their place? Diaphragm again, or vane pumps? I've already replaced the float switches, as they weren't working at all, so I'm not bothered about automatics unless there's a compelling reason to fit them. The current pipe - pickup to filter to pump to through-hull is 1" external diameter, and I'm not anxious to change the through-hulls as they're pretty inaccessible on both sides of the hull. No huge lifting is needed - 18" at best. What will give me my best bang in terms of reliable litres per minute per buck? I'm prepared to pay a sensible price for performance, but the budget for this has to come from other projects, so I'm looking for a price/performance sweet spot.

Supplementary question: The stainless steel on booth engines silencers have corroded joints and significant leaks. I'm advised that they're one-offs. Is it worth trying to get them rewelded or have new ones made, or cut my losses and fit something from the Vetus catalogue (suggestions for other suppliers welcome) The existing ones are quite compact, but I could squeeze in something like this

Thanks in advance.

Apologies for the rambling post - I'm far too hot and far too knackered to be capable of concise thinking!

 

[Refueler]

Being a cheapskate .... I have a cheap chinese copy auto pump in the bilge .... its exact copy of a Rule ....

Like this :

1100GPH 12V Automatic Submersible Bilge Pump Fully Auto Float Switch Internal | eBay

A switch panel that gives me Manual - Off - Auto.

I have same in my Soviet speedboat powered by 7A/hr SLA charged by small solar panel.

With regard to your silencers .... given they are one-offs .... I'd consider re-welding .....

 

[CM74]

With the silencers, the question to ask is "why are the current ones one-offs?"
Presumably it'll either be because standard ones wouldn't fit, or were significantly more expensive than having something made up.

It might be worth taking them off and having a really good look at whether it's just a few isolated patches or joints that are rusted, or whether the whole lot's rotten

 

[Refueler]

Sadly - as you are UK .... costs of repair / replace is not cheap.

Over here - getting a replacement made is often cheaper and better .... my hydraulic cooler on my gearbox, the tubes inside fell apart, Gave it to pal of mine who is Metal Master .... he built a better unit for 20 euros !!

 

[Stemar]

1100GPH 12V Automatic Submersible Bilge Pump Fully Auto Float Switch Internal | eBay

That looks like just the job, and at that price, I could carry a spare!

With the silencers, the question to ask is "why are the current ones one-offs?"

There doesn't seem to be any particular reason for them to be one-offs, though anything much bigger would make access to the engine more difficult, which is something to consider, as I'm not getting any younger, and my ability to clamber into tight spaces is reducing rapidly.

 

[Refueler]

There are lower rated ... 800GPH as well .....

 

[Stemar]

In the end I got Whale low profile pumps, like these, as I wasn't sure if Refueler's pumps would fit under the engine, and I wanted to get it sorted quickly.

But I'm having a problem with them. They're fitted with a couple of inches of hose and a non-return valve, then around 4' of pipe from under the front of the engine, out the back and to the through hull, which is about 15" above the waterline. If the pipe has water in it from the last time the pump ran, the pumps won't prime even though the strum box is well below water level. This applies to both pumps, so it seems unlikely it's a fault with the pump, and both pump well once they are primed. It seems as though it's the weight of the water in the pipe beyond the non=return valve that prevents the priming

Any ideas. please? I don't really want to change them, but will if necessary as ISTM that reliable bilge pumps are essential, and if I can't trust them to prime when the float switch turns on, it means they're likely to run dry for a good while, which doesn't seem like a good idea.

 

[Neeves]

Your pumps sound as if they are dedicated for the engine bays (which will be sealed from the rest of the hull). What happens if you have a seacock fail or run into something hard and unforgiving? We have pumps protection the rest of each hull - and hand pumps with a long enough hose to get to the 4 extremities.

Your silencers are like ours: big rubber tube with stainless end caps. They also help protect the engine from run back of salt water through the exhaust elbow. The end caps are roughly hemispheres with spigot welded on. Its the weld that fails - ours are clearly marked Volvo. They are large, 30cm long 15cm diameter, and make it very difficult to work in the engine bays - whatever you want to do - the silencers are there. I've learnt to live with them. I did look at Vetus silencers - very sexy, sexy price too. I have not decided if I'll upgrade or ......

I am most sympathetic

Jonathan

 

[Neeves]

Which engines do you have?

J

 

[sarabande]

Possibly, just possibly a low voltage to the pump, preventing it from spinning up fast enough to eject water at startup ? Happened with an old grey Whale I had. I remade the connection at a junction box and them OK.

 

[Stemar]

Which engines do you have?

J

They're Beta 20s

Possibly, just possibly a low voltage to the pump, preventing it from spinning up fast enough to eject water at startup ? Happened with an old grey Whale I had. I remade the connection at a junction box and them OK.

Thanks for that - I'll look into it. I think the wires are the right size, they were fine for the diaphragm pumps they're replacing, but a poor contact/corroded connector could do it.

 

[Refueler]

Yes ... either too much voltage loss along the wires ....
or
as you say the pipe run and head of water may be holding that NR valve ...

If the NR valve is removable - just as a test - I would try without .... if it works without NR ... then need to sort why NR is stopping flow.
I have a NR for my under main cabin sole pump ... but after fitting found it did cause a 'slow to get' going flow ... I removed it in the end and extended the pipe to have loop more higher above W/L ..... I have a ball valve at hull side when sailing as iy also serves the galley sink.

 

[vas]

sorry, slightly confused, you replaced diaphragm pumps one on each hull with impeller pumps? is that what this whale is?
as usually impeller pumps wont prime.
I'd use again whale diaphragm pumps tbh, or cheap rule copies (I m using both...)

 

[Refueler]

sorry, slightly confused, you replaced diaphragm pumps one on each hull with impeller pumps? is that what this whale is?
as usually impeller pumps wont prime.
I'd use again whale diaphragm pumps tbh, or cheap rule copies (I m using both...)

Rule .... Seago .... pumps such as these are Impeller and require water level to be at least level with intake / outlet of the impeller casing.

 

[Stemar]

sorry, slightly confused, you replaced diaphragm pumps one on each hull with impeller pumps? is that what this whale is?
as usually impeller pumps wont prime.
I'd use again whale diaphragm pumps tbh, or cheap rule copies (I m using both...)

The diaphragm pumps are original equipment with a tube from the lowest point of the bilge, through a filter to the pump a foot or so above the bilge. They're original equipment and, to judge by their position were fitted before the engines and water tanks, which makes them and their through hulls inaccessible. Since they don't pump - I suspect all the rubber's gone hard over the nearly 40 years they've been there, and I can't get at 'em, I'm abandoning them in place and fitting low profile impellor pumps in the bilges, which have their own completely separate installation. Except they're reluctant to pump too.

Your pumps sound as if they are dedicated for the engine bays (which will be sealed from the rest of the hull). What happens if you have a seacock fail or run into something hard and unforgiving? We have pumps protection the rest of each hull - and hand pumps with a long enough hose to get to the 4 extremities.

The only pumps fitted are for the engine bays. There was a seriously knackered hand pump with a pipe, but I doubt it would reach the bow compartments. I'm reasonably confident that a leak into them wouldn't come close to sinking the boat, same for the cabin bilge, which only has a through hull for the galley sink, which is well above the waterline. A serious leak in the engine bays would certainly bring the engines to a terminal stop, though I doubt it would sink us.

 

[ltcom]

Hope u get it working. I switched to electrically - or water sensing - switches over float switches.

 

[Refueler]

Hope u get it working. I switched to electrically - or water sensing - switches over float switches.

I had one of the rec'd electronic switches ... "Watermaid" ? or similar sort of name ... test was to use a damp cloth. Was fine for about 5 years then just failed .... Given the price of it compared to other means - I did not buy another. I went back to float switched pump via 3 way switch > Manual - Off - Auto.

I also modified a 'worn out' smoke alarm .... smoke no longer activated it. By soldering a twin lead across the TEST button contacts - the other end of the lead with bare wire ends provided the water sensor. Later replaced it with a smaller 'Bath Water' level detector.

 

[Supertramp]

I carry a pump like Refueller suggests as a spare but use a diaphragm pump as the primary pump because I can mount it well above the bilge making it easy to clean the prefilter and service (deep bilge). I ummed and aahed about automatic and fitted a Johnson level switch but mounted it on a tube so I can retrieve it from the bilge to clean. It's sealed and with no floats or moving parts. Strum box cleaning is not easy though.

I have a Whale manual back up and a second grey water pump which can double as a bilge pump.

I have one (deep) hull. It's a good question and not thought about much until the day you discover your system is less than adequate.

 

[Refueler]

Most boats have an excellent back up pump - they are unaware of ...............

The Toilet.

Pipe into bowl ... seal around the pipe where it enters bottom of bowl and you have a manual pump ...