21EC: Mounting 2nd bildge pump

[RockGuy]

I have a 2009 21EC. I am mounting a 2nd bilge pump (a Rule 1100 gph). I am planning to install on the interior of the hull in the void space accessed by lifting the wooden cup holders near the stern. The mounting instructions suggest mounting the pump to the hull using #8 SS screws, short enough so as to not penetrate the hull. (Makes sense to me). So, How thick is the hull? Do you see any problems with securing the pump directly to the hull with screws? And, just out of interest, what is the hull construction anyway. Thanks! John

 

[bob daily]

John, The space under the cup holders would place the second bilge pump too high! And your engine would be half submerged prior to pumping any water. A better location for a second bilge pump would be in the bilge under the access plate between the motor box and the cabin door. There is plenty of room for the pump, easy access, and would place the pump where it would do the most good.
That location places the pump over the keel which should be the thickest fiberglass on the boat.
However if it was me, I would glue some marine wood or other material to attach the pump to.
Good luck with your install. Bob

PS the thickness of the bottom of my 2009 R21-EC was about 3/4 in, a picture of the piece that I took out to install a transducer is in my photo album.

 

[MarcoArias]

John,

I would recommend painting a small piece of 0.5" plywood and puttying it into the bottom of the bilge with reinforced putty. Gelcoat or basecoat would be best, but a urethane paint would work too. I would then mount the pump onto the wood. This would avoid not only going through the hull, but also avoid getting any residual debris from the bilge into the bilge pump over time. It's always good to set a bilge pump just a hair above the mounting floor for that same reason. As said above, you always want the find the lowest point of the bilge for your installation.

 

[Catch22]

I would certainly agree that the proper location for a 2nd bilge pump would be as described by Bob...... I would install it with a block of marine friendly wood like cedar or ironwood or a composite. Bond it to a properly prepared surface with any number of today's marine adhesives......this is will be one of my spring projects once I can spring my boat from quarantine.......keep us posted on your project progress including your electrical and thru hull choices.........good tides........

 

[TylerFromEverett]

I’m also thinking of installing a 2nd bilge pump and I have a couple questions. Why install a Rule and not a Johnson? Also, how do you recommend running the drain line?

 

[iggy]

You can never have too many pumps.......... In the past, I have cleaned a spot and used 3M 4000 fast cure and glued the pump down. I am not suggesting this one, but this type where you squeeze the sides and the motor comes off. https://www.defender.com/product.jsp?na ... id=4014686

You should install a check valve or a anti-siphon loop. You don't want water coming into the boat. I would not worry to much about the pump getting clogged as long as you keep the bilge fairly clean. I would also install a fuse and connect it to a battery that not used for the other pump.

Keep in mind, that a pump rated 500GPH as rated at the hose being at the same level as the pump. If the water needs to pumped up 2 feet. That pump may only be working at 400 or 425 GPH. The higher the thru hull, than the pump, the GPH goes down. Bigger is better.

Good reading.........https://www.practical-sailor.com/blog/b ... nance-tips

 

[RockGuy]

Thanks everyone for for the great advice! I'm set for another "staying-at-home" project.

BTW I picked the Rule 1100 because:

1) It was on sale
2) It has a built in sensor so no separate float switch
3) Relatively high capacity
4) Good reviews
5) Did I mention it was on sale

Thanks!

JB

 

[bob daily]

Tyler, I'm not sure if one type of pump is any better than the other, it would be more of a personal preference as to the manufacturer of the pump. The size of pump, mounting and ease of cleaning and maintenance not to mention cost! Most suppliers have a vast selection of different models and makes.
The discharge of the second bilge pump if located in area that is between the motor box and door under access plate could be run fwd and taped into your drain line for the sink, and discharged on the port. This would be the shortest run for the discharge hose and no need for extra hardware or cutting a new hole in the boat. Some pumps come with mounting panel and switches to make your installation easy and professional looking. Remember to wire the pump to a different battery than the other pump so each bilge pump has its own battery.
Good luck and let us know how your installation goes, a picture would be nice! Bob

 

[BB marine]

You should install a check valve or a anti-siphon loop.

Iggy is right on about anti-siphon loop but the check valve should not be used to take the place of the loop. Most pump manufactures require the discharge be 12" above the water line. If not install a anti-siphon loop but do not use a check valve. If you read the installation manual of most newer bilge pump manufactures it states do not use a check valve in line in the discharge hose. Rule pumps have check valves installed in the pump and state do not use check valves in line. The old style pumps with long runs needed a check valve. Most newer pumps have them built in. A check valve should never be used for installations near or close to the water line to take the place of the anti-siphon loop.


The other point Iggy was making is spot on too lift elevation reduces pump capacity along with:
Pump discharge capacity as installed may be reduced by such factors as:
-length of discharge piping,
-number and radius of bends,
-roughness o f the interior surfaces of hose
-reduction in cross-sectional area of discharge system components such as check valves and thru-hulls.

Just a few things to think about when installing or replacing a pump. I always have questioned the install in my C26. The pump in front of the engine high water pump has no check valve, it has a much longer run and the discharge thru hull is next to the aft pump that has a check Valve. I assume it is to help recirculation of bilge water flowing back. Both thru hull discharges are 6" above the water line no anti-syphon loop. It has never caused an issue but marginal.

 

[ohioan55]

I plan on adding a second pump as well to our R21 in the void forward of the engine compartment. The reason I want a second pump is that I was on an R21 a few years ago that had ankle deep water in the cockpit/pilot house. The reason is that they had many days of rains and storms, they had lost power on the pier and nobody knew it, and the single pump ran the house pump down. So, I am going to install the second pump and power it off of my 3rd (AC) battery bank, just as a backup. It is unnerving to find your boat with that much water in it.

 

[iggy]

I plan on adding a second pump as well to our R21 in the void forward of the engine compartment. The reason I want a second pump is that I was on an R21 a few years ago that had ankle deep water in the cockpit/pilot house. The reason is that they had many days of rains and storms, they had lost power on the pier and nobody knew it, and the single pump ran the house pump down. So, I am going to install the second pump and power it off of my 3rd (AC) battery bank, just as a backup. It is unnerving to find your boat with that much water in it.

You might want to drill and glass in a 1" PVC pipe so the water can drain between compartments. Let say and I hope not!! You hit a rock and start taking on water, As it is now, the water level will have to spill over the compartment walls to reach the other pumps. Not good.

 

[ohioan55]

The void I'm referring to is between the engine and pilot house near the raw water intake on our boat. There is what appears to be a perfect spot there (see Bob Daly post). This second pump would be higher that the first, but still low enough to keep the water below the engine. It really is just insurance since this is my first boat without a self bailing cockpit. Is the void you're referring to under the forward v berth?

 

[bob daily]

Ohioan-55 I believe if you look at the space we are talking about you will see a piece of material with a few screws holding a piece in place that blocks the bilge area in the cabin bilge from the bilge area under the motor. It is not water tight but if you wanted more flow from the cabin area you could modify it to your liking. Personally if I have that much water coming into the boat I'm putting on my life vest, grabbing my insurance papers and buying a bigger boat! Always look at the brighter side.
Bob

 

[Fisho]

Hi all, worth reading previous threads on installing a second bilge pump on 21EC. A relatively easy instal next to existing pump. I used a similar but larger 1000 gph Johnson, a separate switch, fuse and matching outlet. Kept it simple. Great as a backup and works a treat. Cheers.