Association Forum - Bilge Pump discharge

Assn Members Area · Join

Home.

Association Forum

Ships Store

Cruising

Racing

Technical Tips

Photo Gallery - New

Boat Search - Updated

Manuals & Brochures

Swap Meet

Links

Officer Flag Line & Staff

Bylaws & Constitution

Members Area

Join the Association

Notice:
The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.

Association Forum

Username:	Password:
Save Password
Forgot your Password?

All Forums

Catalina/Capri 25/250 Sailor's Forums

General Sailing Forum

Bilge Pump discharge - duh?

New Topic

Topic Locked

Printer Friendly

Previous Page | Next Page

Author

Topic

Page: of 3

Dave Bristle
Master Marine Consultant

Members Avatar

Djibouti
10005 Posts

Response Posted - 06/12/2008 : 12:41:04

There's another way to slow down a Daysailer, John... It's when raccoon sh!t from a crab feast in the cockpit clogs up the scupper so the boat fills with enough rain water to reach the centerboard cable hole and fills up the bilge with brown water... But that's purely hypothetical!

Edited by - Dave Bristle on 06/12/2008 12:43:07

piseas
Former Treasurer

Members Avatar

USA
2017 Posts

Response Posted - 06/12/2008 : 14:13:51

After some deliberation, I have decided to go with Rule RM1100 and install thru hull next to manual thru hull. I haven't checked out install manual yet but was wondering what size thru hull most used?
Steve A

Edited by - piseas on 06/12/2008 14:14:43

Nautiduck
Master Marine Consultant

Members Avatar

USA
3704 Posts

Response Posted - 06/12/2008 : 15:07:58

Thanks Steve, now I'm the only crazy one.

Please take and post photos. I'll probably end up needing them.

Edited by - on

delliottg
Former Mainsheet C250 Tech Editor

Members Avatar

USA
4479 Posts

Response Posted - 06/12/2008 : 15:45:12

This may seem counter intuitive at first, but bear with me.

Something to consider when sizing your pump. Relatively speaking, our boats have little in the way of interior space compared to larger boats. While that statement might seem obvious, you may not understand just how much more interior space (to fill with water) a larger boat contains. Because of this, you want to have the largest capacity pump you can fit in your bilge because it takes relatively little water to sink a 25' boat. On a larger boat, you can afford a somewhat smaller pump because you have significantly more volume to fill before it'll sink, which translates into more time. Volume changes by the cube of length, so a longer/wider boat has a much much greater water carrying capacity before reaching negative buoyancy. On our boats a two inch hole would probably sink us in just a few minutes, on a 40' boat, you'd have more time to look for & plug the hole. I haven't done the math on this, but I'm sure of the result.

Of course a larger capacity pump won't run as long as a smaller pump on a given number of amps, but what good is a smaller pump that's still running going to do you when your boat's already on the bottom? A bigger pump moves more water faster, so you can spend that time looking for and plugging leaks instead of manning the manual pump as well just trying to stay ahead of the leak.

Also don't forget about static head, a larger pump can push harder against the water that's already been through the pump, but not over the side yet. The higher your discharge port, the more static head, and since we're talking about sailboats that heel, we want our discharge ports as high as possible to prevent siphoning back into the boat. The larger your pump & discharge hose, the easier it is to get the water over the side due to reduced friction in the hose. More of your amps are spent getting water over the side, and less pushing it against friction.

Oh, and before you ask, SL doesn't have a bilge pump...yet. Fortunately our bilge has always been dry with the exception of condensation. That doesn't mean I'm not putting in a pump, I just haven't gotten to it yet.

Edited by - delliottg on 06/12/2008 15:47:16

piseas
Former Treasurer

Members Avatar

USA
2017 Posts

Response Posted - 06/12/2008 : 16:23:30

[quote]Originally posted by delliottg
 This may seem counter intuitive at first, but bear with me.
On our boats a two inch hole would probably sink us in just a few minutes.

David, yikes, now you got me wondering if any electric pump will be of value, whether it be 1100gph or 2000gph and using the largest discharge hose or largest thru hull. No wonder Catalina doesn't put them on as a stock item! Well I better have my dink in tow every time I go out even though my bilge is dry as a bone too.
Has anyone actually had a small hole and used the pump and survived in one of our boats?
I am not an engineer but if this is the case, sounds like no matter what, we are going down.
Steve A

Edited by - on

delliottg
Former Mainsheet C250 Tech Editor

Members Avatar

USA
4479 Posts

Response Posted - 06/12/2008 : 16:32:28

I don't know about our boats, but an attorney I used to work with a long time ago decided to disconnect his head intake valve while it was still in the water on his 36' sailboat. They managed to keep the boat from sinking, but only just. The irony was, the guy that was helping him was a civil engineer who did most of our sewage, stormwater & fresh water designs, so he knew all about pipe sizes, laminar flows, and head. Apparently they had about a foot of water over the sole before they got it plugged. I'll bet that was an exciting few minutes!

I think the object of a pump in our boats is simply to give us time to find & plug the leak. If you're swinging on a ball with only your battery to keep the pump going & you've got a leak, the boat's going down. However, if you hit something while you're sailing, a big pump gives you a much better chance.

Edited by - delliottg on 06/12/2008 16:45:54

piseas
Former Treasurer

Members Avatar

USA
2017 Posts

Response Posted - 06/12/2008 : 17:07:01

Sten or anyone else, you've got the 2000gph pump. What size exit hose and thru hull did you install?
Steve A

Edited by - on

JimB517
Past Commodore

Members Avatar

USA
3285 Posts

Response Posted - 06/12/2008 : 17:53:01

I bought the 500 gpm pump to save a few dollars, then worked for days installing it. After all that work, I wish now I had gone larger.

I used 1 inch hose all the way to the stern.

My pump is in the keel well as low as possible. Not sure if a larger one would have fit.

When I was done with the job I opened a through hull and let a bunch of water in to see if it worked. It did, but no way would it keep up with a 1 inch hole on the bottom of the boat.

I don't have an alarm but I think the sound of water pumping out the stern would be hard to miss.

The purpose of the pump is peace of mind and to give yourself time to find and fix a minorminor leak taht occurs offshore (not in the slip when you are not there).

Also, PHRF offshore racing requires 2 pumps on board, 1 manual, so I installed it for compliance.

Edited by - on

piseas
Former Treasurer

Members Avatar

USA
2017 Posts

Response Posted - 06/12/2008 : 18:13:45

Jim, thanks. Others have installed an 1100 and it fits other side of keel bolts. Did you make new thru hull at stern (where exactly) not next to manual pump thru hull. Also how did you afix pump, using adhesive or mount.
Any tips you have to make job easier and not 2 days would be appreciated.

Steve A

Edited by - on

Tom Potter
Master Marine Consultant

Members Avatar

USA
1913 Posts

Response Posted - 06/12/2008 : 19:19:27

Installed a Rule 1100 with a built in float Switch. Put a three way switch over by the Propane switch (C250). Ran the power wire straight to the battery with a fuse at the battery, by passing the breaker panel. I wanted the pump to have power 24/7. I ran a 1 inch separate discharge hose along side the manual pump hose all the way back to the stern. I installed a thru hull next to the manual pump thru hull. Here's a couple pictures.

Here's the hose (white) as it runs up and thru the wet locker.

Hose running in the troff in the aft berth.

Here's the thru hull.

The switch is located just to the left of the fan.

Edited by - Tom Potter on 06/12/2008 19:24:43

piseas
Former Treasurer

Members Avatar

USA
2017 Posts

Response Posted - 06/12/2008 : 20:35:05

Tom, I saw your install, quite nice. I will copy it except I will omit switch. Your setup is meets my KISS rule. Guess you didnt feel 2000gph was necessary.
Steve A

Edited by - on

Nautiduck
Master Marine Consultant

Members Avatar

USA
3704 Posts

Response Posted - 06/12/2008 : 21:17:57

Tom, thanks for posting the photos. I still think the primary benefit of such a bilge pump is at the dock while you are away and a slow leak happens at a thru-hull.

Edited by - on

redviking
Master Marine Consultant

Members Avatar

USA
1771 Posts

Response Posted - 06/13/2008 : 09:25:58

Quote: "Sten or anyone else, you've got the 2000gph pump. What size exit hose and thru hull did you install?
Steve A"

SV Lysistrata has an 1100 installed. My 2000 GPH is NOT installed. It has a cigarette lighter plug which is also teed off to accept the generator plug. The idea here is that in case of an emergency I can plug it in and discharge what the installed bilge pump can't handle. Also, should someone else be in trouble, we can easily assist with this system... My wife calls me "Mr. Backups for backups."

Sten

DPO C25 #3220 "Zephyr", SR, FK
SV Lysistrata - C&C 39 - Newport RI

Edited by - on

Tom Potter
Master Marine Consultant

Members Avatar

USA
1913 Posts

Response Posted - 06/13/2008 : 11:27:16

You could also drop the pump over the side and have a salt water wash for your anchor.

Edited by - on

piseas
Former Treasurer

Members Avatar

USA
2017 Posts

Response Posted - 06/13/2008 : 15:05:37

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Nautiduck
 a slow leak happens at a thru-hull.
<hr height="1" noshade id="quote"></blockquote id="quote">
Randy, I am trying to imagine how a slow leak at the thru-hull(next to the manual pump exit thru-hull) will happen.
Steve A

Edited by - on

Nautiduck
Master Marine Consultant

Members Avatar

USA
3704 Posts

Response Posted - 06/13/2008 : 15:09:13

Steve, I mean a thru hull like the depth and speed transducers. Not the discharge hole for the bilge pump. A leak of one of those underwater thru hulls is what I see an electric bilge pump being good for.

Edited by - Nautiduck on 06/13/2008 15:12:27

piseas
Former Treasurer

Members Avatar

USA
2017 Posts

Response Posted - 06/13/2008 : 17:04:30

Randy, thanks for clearing that up. And you said what I fear re transducer thru-hull. Thats why I am looking at shoot thru(in hull) transducer for a chartplotter. But since I am looking at installing elect bilge pump and buying Delta anchor at WM(its on sale), chartplotter is down the road.
Steve A

Edited by - on

delliottg
Former Mainsheet C250 Tech Editor

Members Avatar

USA
4479 Posts

Response Posted - 06/13/2008 : 18:32:20

FWIW, I just got back from Fisheries Supply with a Rule 2000, float switch & three way bulkhead switch, 20' of 1-1/8" discharge hose, a through hull and some SS clamps. I don't even know if the pump will fit in the bilge, it was a snap decision to buy all the stuff after Rita read this thread. At worst, I return the pump for a smaller footprint pump. I don't plan on installing it before we splash, I'm simply going to rig it similarly to Sten's, wired with a cigarette plug adapter & ready to go if we (or someone else) need it. I'll install it properly next winter, I'm tired of projects for this "winter". I want to sail, not work on the boat...

Edited by - on

piseas
Former Treasurer

Members Avatar

USA
2017 Posts

Response Posted - 06/13/2008 : 22:56:29

David, this is one purchase that gives you piece of mind. But not sure about waiting till winter. But I understand you wanting to sail and not work.
The difference in height between the 1100(one I am buying tomorrow) and the 2000 is 2"s. I will let you know if thats a problem. I have an 03, 250.
Have you given thought how to cut thru hull?
Steve A

Edited by - piseas on 06/13/2008 22:57:53

delliottg
Former Mainsheet C250 Tech Editor

Members Avatar

USA
4479 Posts

Response Posted - 06/13/2008 : 23:22:32

The [url="http://www.rule-industries.com/products/pumps/bilge_pumps/rule_2000/iid_256/index.htm"]Rule 2000[/url] will fit, but it won't sit on the bottom of the bilge, it'll be above the keel bolts, but that's close enough for me, the manual can get the rest. I'll have to build a little shelf for it to sit on, probably out of lexan so I can still see my keel bolts without removing it.

As far as the through hull, I'll probably use an oversized hole saw, backfill with thickened epoxy & redrill the correct size, whatever fits the through hull. I plan to put it the same place as Tom did, right next to the manual pump's discharge, unless I can find a convenient place that's closer, as closer means less static head to pump against.

As far as not installing it till next winter, I'll rig it so it can be left to discharge into on of the sinks or something when we leave the boat, or maybe I'll do the install over one of our not-so-nice weather weekends this summer. At least it'll be on board and usable.

Edited by - on

britinusa
Web Editor

Members Avatar

USA
5404 Posts

Response Posted - 06/17/2008 : 22:35:39

I ended up following the advice of the team. The new WM 800GPH pump is installed in a removeable pallet in the bilge and plumbed into a new thruhull above the stripes and directly above the AC discharge. Works a treat during tests. The control panel is above the std electrical panel stbd side cabin.

Paul

Edited by - on

Nautiduck
Master Marine Consultant

Members Avatar

USA
3704 Posts

Response Posted - 06/17/2008 : 23:43:30

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Works a treat during tests.<hr height="1" noshade id="quote"></blockquote id="quote">

What are you, British?

Edited by - on

Nautiduck
Master Marine Consultant

Members Avatar

USA
3704 Posts

Response Posted - 06/18/2008 : 14:21:56

David, can you take a photo of where you will put the 2000? I don't see how an additional 2" will fit given the photo of the 1100.

Edited by - on

britinusa
Web Editor

Members Avatar

USA
5404 Posts

Response Posted - 06/18/2008 : 15:19:48

Here's a sketch of the base system I developed.

I have used this method to secure the wash down pump and the bilge pump to the inside of the hull without screws.

The system consists of two parts, both are cut out from starboard (I use wallyworld cutting boards, they are about 1/4" thick.)

I cut out the pieces using a coping saw with a very fine blade.
The center piece has sloping sides.
The outer U shaped piece is glued to the inside of the hull.
The fixtures (in my case 'pumps') are screwed to the removeable base plate.
The removeable base plate simply slides out of the fixed base plate, the sloped sides keep it in place.

In the picture the fixture is represented by the blue circle and securing 'ears' typical of most pump fittings.

My intent was to create a system that would allow me to remove the fixture and replace with a new possibly different model and not to have to drill new holes in the hull.

The inner plate fits pretty snugly and there has been no need for any method of securing the removable plate from the fixed plate, but a simple piece of velcro or a couple of short screws in each piece with a tie wrap would be plenty.

If I need to replace the fixture with a new different shaped model, if needed I could simply cut a new removable base plate and attach the new fixture to it.

Paul

Edited by - on

piseas
Former Treasurer

Members Avatar

USA
2017 Posts

Response Posted - 06/18/2008 : 15:49:57

Paul, nice diagram. Surprised you didnt video the entire project!

If you go to the Rule web site, they talk about using epoxy on the bottom of the pump as well as having a mount for a couple of bucks-on WM site-that can be attached 1 of 3 ways.
Steve A

Edited by - on

Page: of 3

Topic

Previous Page | Next Page

New Topic

Topic Locked

Printer Friendly

Jump To:

Association Forum

Notice: The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.