4000GPH bilge pump going to be installed on my 16ft RIB

[jonascramm]

haha so i went white water rafting the other day and my boat got swamped and my little 500GPH rule pump just did nto get the water out fast enough i had to actually go over to the shore and let the pump get all he water out, it took about 10minutes haha, meanwhile i was missing all the good waves. so i bought a 400GPH Johnson pump. anybody have any thoughts on that make of pump? or how i should wire it up? i will assume it is going to be big enough, it was the biggest i could find, unless i went to a double pump set up. also does anyone have any idea how i can seal my rigging hose that houses all my engine cables and wiring that goes tot he battery underneath my center console. when i went rafting and the boat filled up with water, so did underneath my seat and battery box haha. is there such thing as an expanding silicone that i could spray in there and it would fill on the nooks and crannies? kind of like the spray insulation u use in ur house, but waterproof? thanks

[Limey Linda]

Put two big holes in your transom with trunks . problem solved. if you mean a 4000 pump then it will kill your battey quickly, gross overkill and wrong solution to the problem.

[Rigaud]

Originally Posted by Limey Linda

Put two big holes in your transom with trunks . problem solved. if you mean a 4000 pump then it will kill your battey quickly, gross overkill and wrong solution to the problem.

I agree, I don't do white water rafting but do have transom drainage and works great.

[Polwart]

Originally Posted by Rigaud

I agree, I don't do white water rafting but do have transom drainage and works great.

but generally for them to work you will need to be able to get onto the plane (or atleast good speed through the water). I'm not sure if that is achievable in "white water rafting" situations.

If you have no other electrics running then I would expect the alternator to keep up with a 4000 GPH pump (although not looked up the current draw) - but my preference if I was routinely expecting to take on serious water would be two pumps anyway as a backup (each with own wiring). But transom drains/scuppers are definitely preferred if possible.

[jyasaki]

There are some expnding urethane foams you could try for sealing, but I'd personally hate to have to do work on that area after you spray it in...

When you say "white water rafting", were you under power? Or motor out of the water and drifting? Not really clear on the concept as described.

If you're filling the boat with large amounts of water, it's going to take some time to pump it overboard no matter which pump you use. Any pumps effectiveness is further reduced by head (the height you're pumping the water to) and hose diameter (smaller means more restriction.) In general, a pump rated at X gph will pump 1/2 to 3/4 X gph when actually installed in a real-life situation. And, as LL mentioned, bigger pumps suck more current.

jky

[Stoo]

Originally Posted by jyasaki

Any pumps effectiveness is further reduced by head...

Ain't it the truth... It's such a distraction~

[prairie tuber]

Originally Posted by Limey Linda

Put two big holes in your transom with trunks . problem solved. if you mean a 4000 pump then it will kill your battey quickly, gross overkill and wrong solution to the problem.

I agree. A pair of proper scuppers with elephant trunks are going to drain the vast bulk of the water in a swamped RIB or SIB much faster than any bilge pump will. The main role of bilge pump (I just use a manual pump) should be to get rid of the last few of inches of water below the bottom of the scupper opening. I've had my 16' SIB completely swamped while in a whitewater river this past summer. The 4" diameter scuppers performed perfectly and were able to drain all of the water to the bottom of the scuppers within about 30 seconds while under power at a speed well under planing speed.

[jyasaki]

PT: Are the ends of your trunks cut like that to prevent static buildup?


jky

[prairie tuber]

Originally Posted by jyasaki

PT: Are the ends of your trunks cut like that to prevent static buildup?


jky

Yup - makes it easier to adjust the squelch on my VHF



I'm not sure if the frilly pattern is functional or not. Perhaps it helps the ends of trunks stay flatter (more closed) when water is not draining.

[Limey Linda]

Originally Posted by jyasaki

PT: Are the ends of your trunks cut like that to prevent static buildup?


jky

They match is eyebrows