C-Forum

Getting ready to outfit the Nitro with a dual-bilge system. Let's pretend money wasn't an option....is there a fast-acting, high-volume pump out there on the market? Where can I find a pump? Online sources? Online kits?

Additionally, any tips on outfitting. Placement/materials etc.? Thanks.

If you want to use Attwood Tsunami 1200's you can find them at Wal-Mart for under $40 each.

http://cgi.ebay.com/ebaymotors/New-Attw ... _748wt_941

ebay has many pages of bilge pumps, including 4 pages of attwood pumps. Since I'm cheap and use SLA batteries I really liked the old v1250 pumps, but the Tsunami 1200 is a fine pump.

David, I prefer the old V1250 as well, but the Tsunami works fine with an SLA battery. It just takes a larger one. I think I'm using a 4.8 Ah with a Tsunami in a Spark where the V1250 took a 2.3 Ah battery. The nice thing about the Tsunami is that it press fits nicely in the space between the saddle and the foam block to which the foot peg rails are mounted without modification. I hollow out a spot for the battery in that foam block and hold it down with a piece of bungee.

any electrical engineers out there know how multiple batteries in series affects mAh / Ah value? I have 12 rechargeable AA in series in my home brew power supply pack. Wondering how much "ooomph" I'm lacking with this approach vs a big block'o'energy like your single SLA.

Wal-Mart. Go figure. I'll have to check it out.

cheajack wrote:David, I prefer the old V1250 as well, but the Tsunami works fine with an SLA battery. It just takes a larger one. I think I'm using a 4.8 Ah with a Tsunami in a Spark where the V1250 took a 2.3 Ah battery. The nice thing about the Tsunami is that it press fits nicely in the space between the saddle and the foam block to which the foot peg rails are mounted without modification. I hollow out a spot for the battery in that foam block and hold it down with a piece of bungee.

Why does the tsunami need a larger battery?

mr ray wrote:any electrical engineers out there know how multiple batteries in series affects mAh / Ah value? I have 12 rechargeable AA in series in my home brew power supply pack. Wondering how much "ooomph" I'm lacking with this approach vs a big block'o'energy like your single SLA.

All the current must pass through each plate/battery no matter what, but the rechargeables might have more internal resistance. (Even a Lead-acid battery only generates about 1.5V per plate.) You can tell whether it's a factor if the AA batteries get hot under load. That indicates high internal resistance - and a loss of power to the pump.

The Tsunami 1200 draws juice about twice as fast as the v1250. I use a small battery to save on weight. I've still never depleted a fully charged battery on a single river trip, and you can recharge on the drive home. I only run a single pump. Eventually I'll go with 2 pumps and a lighter, stronger battery.

The Tsunami 1200 draws juice about twice as fast as the v1250

Well that sucks (no pun intended) - I assume it's the same gph rating judging by the name. Wonder why they would make half as efficient?

Don't know. But the Tsunami is a nice pump. As Jack says, the Tsunami series have a much smaller profile than the v series pumps.

I'm going to start gathering my materials this week. I'll pick up the pumps tomorrow from Wallyworld. Any advice on tubing? I'm thinking about making short runs that pop out on either side of the boat behind my feet (So my feet can't get caught up in them.) I'm planning on placing the pumps up against the back of my seat to hopefully suck up most of the water. As far as the switch goes, I'll likely place that behind the seat as well.

But again...any ideas on tubing or where to buy it? Also, I can likely get the switch from a hardware store, correct?

One last thing...the white ring I see on the exterior of people's boats where the water shoots out...where can I get one of these?

To answer the OP. Dual-bilge sounds like overkill for a nitro. I would put in the biggest bags you can find and some sidewall foam and go with a single 1200 gph the others have mentioned. The 1200 gph seems to be about the right size for a playboat (takes about 15 seconds to empty my prelude when it's completely full).

Since money is no object, the LiPo batteries will give you the best energy density/weight ratio. They do cost about 10x an SLA - and I question the ruggedness. I've also had several friends with NiMh battery packs that died on them prematurely because one of the cells goes bad.

I've been using a 3.2 Ah SLA for the last 4 seasons and it is still going strong. Heavy @ 3lbs. but I like that it's cheap and I don't have to baby it (although I always charge it after use) Using an attwood v1250 I think I have run out of juice maybe 1 or 2 times towards the end of a long day trip -- and that was in a phantom which holds a lot more water, so I was running the pump a lot more.

You can a thru-hull fitting at any marine store. West Marine stocks them. I've picked some up at Wal-Mart, but my local store doesn't carry them any longer. Home Depot/Lowes carry tubing. Wal-Mart carries an installation kit that includes tubing, tubing clamps, and a thru-hull. I use a cheap dry box from Wal-Mart to hold my battery and switch. Just drill a small hole in the box to run the wires into the box. Use some kind of wire attachment outside the box so that pump and battery/switch/box can be disconnected. Drill a larger hole in the box to mount the switch. You can get a cheap plastic switch for under $2, but you'll break it. Spring for the extra couple of bucks and get a metal one. Once I've installed it, I build up many layers of liquid electrical tape to try to keep the switch relatively dry. I use foam scraps inside the box to keep the battery still and as dry as possible. I don't use a fuse. The dry box has slots to pass a webbing strap through. You can pretty easily end up with something that can move from one boat to another in just a few minutes.

Why drill a hole in your boat for a through the hull fitting? I just run the tubing from the pump up and across the boat hanging over my onside gunnel. I hold the tubing in place with cable ties around the tubing and bag strings. Be careful with the installation kits at Wally World. The last time I was in our local store the tubing in the kits was smaller in diameter than that required for a Tsunami series pump (1 1/8" I think). I get tubing from West Marine and switches from True Value Hardware or Radio Shack. I have used SLA batteries in six boats now and never have tried to waterproof the switch or battery "housing" and never have used a fuse and have never had trouble. I do break the hot leg (brown wire if you get an Attwood pump) at the switch. I mount the switch on the front of the saddle. I mount it to a piece of ABS and glue the ABS to the foam. This requires over drilling the place where the wires come through using an 1 1/4" paddle bit so the switch will fit flush. I solder all joints and cover with heat shrink tape. If you want to move the pump from boat to boat, only solder the wires at the switch and use pull apart connectors everywhere else. On boats with a bulkhead type saddle, I mount the switch on a thwart making a mounting bracket out of a small piece of aluminum 1" angle. I have paddled six days with an Attwood V1250 and 2.3 Ah battery in an Ocoee that is pinched and foamed out without recharging. I think the Tsunami series will drain a battery faster than that but have paddled an entire weekend without recharging the battery. Large bags and additional foam to displace water is a good idea if you don't mind the weight.