I want to drill holes in the bottom of the hull.

[Mark42]

Installing a bilge pump (Attwood Sahara 750gph) in the Capri. Would like to mount the pump directly on the hull, rather than epoxy a piece of wood to the hull and screw the pump to the wood. That will raise the pump at least 1/2" and I want the pump to go on ASAP.

So I'm wondering how thick is the keel on my Capri? It looks to be about 1" or so. But before I put drill to hull, I thought I'd ask my fellow Bayliner owners if anyone has screwed their bilge pump right to the keel? Any idea how thick it is?

I plan to use 5/8" stainless screws, and with the thickness of the pump base, only about 1/2" or less will protrude into the hull.

Thanks!

Mark.

 

[azlakes]

Re: I want to drill holes in the bottom of the hull.

... hiya Mark,

how thick dont know exactly, but on my bl there looked to be an embedded mount pad just for the bp. so all i had to do was use that location and laid a bead of silicone adhesive along with the ss mount screws. i would look on yours for this bp spot. if not i would think a 1/2" and some adhesive would be fine for your b-pump. btw take a look at the other post about a ladder u were looking for. i think i have one.

 

[mthieme]

Re: I want to drill holes in the bottom of the hull.

Another popular way (around here) of doing it is to epoxy a plastic coffee can down and attach the pump to it. You'll need holes around the bottom of the can of course. You can attach the pump to the side of the can instead of the bottom.

 

[Lone Duck]

Re: I want to drill holes in the bottom of the hull.

Another popular way (around here) of doing it is to epoxy a plastic coffee can down and attach the pump to it. You'll need holes around the bottom of the can of course. You can attach the pump to the side of the can instead of the bottom.

Interesting. You could also epoxy an L shaped piece of wood to the bottom of the hull and screw a B P to it at any height you choose.

 

[Mark42]

Re: I want to drill holes in the bottom of the hull.

Those are interesting ideas, but the Attwood Sahara series pumps are automatics, and must be mounted upright for the internal float to work. I'm pretty sure that the keel is well over 1/2 inch.

Another thing about the 1600 Capri is that the space for the fuel tank is recessed about 2 inches down between the stringers into the bilge space right in front of the tansom.

There is no space behind the fuel tank for the bilge pump, so its has to go right in front. Not sure how the hose will run yet, because the instructions say it must be all uphill from the pump with no sags where water can sit causing an air lock. Hmmmm thats going to be tricky. It would be easy to run the hose under the gas tank and up behind it (there is a little space behind the tank) and out the the thru-hull. But that means there will be a sag under the tank, and that can cause an air lock.

Been too cold outside to go check out the boat in person, but I'm sure routing the hose will be a challenge.

 

[redone4x4]

Re: I want to drill holes in the bottom of the hull.

Installing a bilge pump (Attwood Sahara 750gph) in the Capri. Would like to mount the pump directly on the hull, rather than epoxy a piece of wood to the hull and screw the pump to the wood. That will raise the pump at least 1/2" and I want the pump to go on ASAP.

So I'm wondering how thick is the keel on my Capri? It looks to be about 1" or so. But before I put drill to hull, I thought I'd ask my fellow Bayliner owners if anyone has screwed their bilge pump right to the keel? Any idea how thick it is?

I plan to use 5/8" stainless screws, and with the thickness of the pump base, only about 1/2" or less will protrude into the hull.

Thanks!

Mark.

i am in the same situation, trying to mount my new pump to the hull but i cant reach the factory installed block easily enough. I was thinking about screwing into the hull just barely, but i couldnt find an answer to this.....

 

[Mark42]

Re: I want to drill holes in the bottom of the hull.

redone4x4, This weekend it's supposed to get into the 50's. I'll do a drill test into the keel from the bilge and see if 1/2" protrudes through the bottom. If it does, then out comes the marine tex and patch the hole. Probably only 1/8 " bit wil be used, so no big deal. Will keep you posted.

Regarding the air lock that the instructions warn agains, can anyone tell me how this air lock business works? I understand air lock in a closed loop system, but I didn't think it could happen in an open end system. The pump is not strong enough to push air and water out the hose, but it can push just water?

Here is a link to the install doc: http://www.attwoodmarine.com/products/Install_Instructions/69370-C Sahara Pumps.pdf

 

[redone4x4]

Re: I want to drill holes in the bottom of the hull.

redone4x4, This weekend it's supposed to get into the 50's. I'll do a drill test into the keel from the bilge and see if 1/2" protrudes through the bottom. If it does, then out comes the marine tex and patch the hole. Probably only 1/8 " bit wil be used, so no big deal. Will keep you posted.

just curious, did u ever check this out? i still havent solved my bilge pump situation...

 

[fishrdan]

Re: I want to drill holes in the bottom of the hull.

(edit) AHHH SHOOT, didn't see you had posted this a few weeks ago,,, oh well

How about epoxying the bilge pump right down to the hull? I've done this on a few and have been able to remove them again by prying the pump's base off and then scraping the epoxy off the hull,,, kind of a semi-permanent installation. I used the cheap 5 minute epoxy which probably helped in removing the base so it wasn't a permanent part of the boat.

I'm not sure what they are talking about with pump air-locking since water will be flooding the pump if it's on,,, and any air will easily be pushed out of the discharge hose Heck I've even had bilge pumps being submerged, then dry, then submerged, then dry,,, as the boat rocked in heavy seas and the bilge pump primed itself again and continuing to pump. Maybe something to do with the design of this specific pump???

 

[Mark42]

Re: I want to drill holes in the bottom of the hull.

(edit) AHHH SHOOT, didn't see you had posted this a few weeks ago,,, oh well

How about epoxying the bilge pump right down to the hull? I've done this on a few and have been able to remove them again by prying the pump's base off and then scraping the epoxy off the hull,,, kind of a semi-permanent installation. I used the cheap 5 minute epoxy which probably helped in removing the base so it wasn't a permanent part of the boat.

I'm not sure what they are talking about with pump air-locking since water will be flooding the pump if it's on,,, and any air will easily be pushed out of the discharge hose Heck I've even had bilge pumps being submerged, then dry, then submerged, then dry,,, as the boat rocked in heavy seas and the bilge pump primed itself again and continuing to pump. Maybe something to do with the design of this specific pump???

Hi Dan!

I ended up just epoxying down a piece of 1/2" pt ply and screwed the pump to it. Sometimes ya just gotta go with the flow (pun intended )

As far as the air lock, the problem is if the hose has a dip that holds water, the pump will not flood with water. Like turning a glass upside down and submerging in the sink, water can not enter the glass. Same with the pump, if air can't get out the hose, water can not flood the pump and prime it. So even if the pump is submerged, there is a big air bubble around the impeller and it won't pump air.

The solution is a small hole drilled in the pump housing, maybe a 1/16" or smaller just to let air out as water rises. The drawback is water shoots out the hole when the pump runs. So its best to keep the hole as small as possable and make it on the underside of the discharge part of the pump.

But if the hose has no dips, then this is not a problem.