Custom ballast - anybody use a 2" Thruhull?

I've been doing a ton of research over the last few weeks on my own custom ballast system. I've decided to do an aerator style for speed, but also because I already own all of the pumps. I was hoping to do the whole system (4-5 Tsunami pumps) off of a single homemade manifold in the rear of the boat. I've read about many people installing 1 1/2" thru-hulls, but haven't heard of anybody going bigger. Please let me know if you have done so or if you have heard of any problems arising from going that big. There will be a brass shut-off valve first thing on the inside of the boat.

I would think the biggest problem would be finding the hardware to accommidate 2" plumbing.

i know I can get my hands on a 90 degree elbow and a 2" brass ball valve at Menards, I haven't checked on the thru-hull itself, i don't think it would be a problem at west marine or the like. I could be wrong.

After the ball valve the plan is to have a homemade PVC manifold, so I would just need a 2" connection between the manifold and the brass ball valve.

In all the catalogs and online stores I've seen, the only options are 1" and 1.5". You might want to check some places that cater to yachts or houseboats.

Post pics of you manifold and setup. I just picked up my Pro-X series bags and plan on doing the same thing myself. I am looking at going with a 1.5" thru-hull and a 3800gph Rule pump to fill 3 bags. Each bag will have an 1100 pump for empty.

First of all building a manifold usign all 2 inch PVC woudl be really big I would think? Where would you put it? Secondly I would think system will only flow as fast as the smallest diameter hose/fitting will allow. on top of that the opportunity cost of going with a 2inch is probably not even worth the hassle.

I'll be sure to document the entire install process. Right now I'm kind of in the research phase.

Rich, are you just going to split the hose 3 ways off of your pump? My thought is to have one manifold with a dedicated pump per bag so that I can control the level of each bag individually. I will also have a dedicated pump and thru-hull (up on the rubrail) for the draining of each bag.

Here is a link to a place to get 2" thru-hulls:
http://www.shipstore.com/SS/HTML/CNN/CNN65BN807.html

West Marine carries the same ones made by the same company - but they are about $10 more.

Adam,

The thought was just to have a 2" thru-hull and elbow to basically allow a bunch of water to flow up into the homemade manifold. I figured in order to have 4-5 pumps run at the same time there would need to be a large "pool" of water available to them. The manifold itself would sit in the bilge (port side). The pumps would be attached to the manifold and 1 1/4" flexible tubing would run to each bag from there.

Correct me if I'm wrong, but the goal of a ballast manifold is to bring in the water "in bulk" so to speak before diverting it into pumps and bags? In my case, I figure if I can keep the whole manifold under the water line, the manifold will constantly be full (assuming the ball valve is open) and the pumps can feed off of that water.

Ballast experts, please correct me if I'm wrong. I don't want to drill into the boat for something that won't work! Thanks!

You can also get a thru hull scoop ( like the one that is for your raw water intake ) This would force water into the main manifold, and fill much faster when you are under way. I have this set up with 4 pumps and my sacs fill within 3-5 min, easily.

http://www.go2marine.com/go2_structure/5/4/4/6/54468F-p.jpg

The problem with ballast pumps is that they air lock from running without water in them. You want to have the distance from the thru-hull and the pumps to be as short as possible (ideally, mount the seacock valve directly to the thru-hull and the pump directly to the seacock) This way, if you have a scoop/strainer rear facing (if they face forward your ballast will constantly fill while driving unless you close the seacock valves)underwater you can drive the boat in reverse to force water into the pump and get them to start filling the bags if they airlock. The further the water has to travel to the pumps, the more likely they will not suck up any water and you'll have a hard time forcing water into them. If I were you, I'd have a seperate intake thru-hull for each intake pump. The other thing you may want to check out is a check valve on each intake, that way your bags won't empty out your intake while you are driving, some pumps may work as check valves (meaning the water can only flow one direction) but the attwood tsunami's do not.

here is an electric valve that can be controlled @ the helm. Fill the sacs to where you like and then close it. The manifold (with the 4 pumps connected) is directly after the gate valve.

http://www.phasefourindustries.com/staticpages/index.php/dm_cart

Erik, the one big pump will go into a manifold then split 3 ways, with a manual shutoff valve on each hose. Each bag will have an overflow. When the first bag fills, probably the locker, you shut if off then the fill rate increases for the back bags. you could also fill one side or the other for surfing.

I am going with the strainer-scoop type thru-hull.

Here is another option for remotely operated valves, although these are mechanical/cable actuator type:

https://www.flow-rite.com/store/marine/retail/marinestoreretail.html
Click on "Valves" when you get to the link

I do not want to get quite that sophisticated on my system.

(Message edited by Rich_G on December 12, 2006)

Rich,

I'm in agreement with you on the lack of need for electronic valves. I think with the right check valves to prevent backflow, I wouldn't have a problem having a manual "master" ball valve who's primary purpose would be to stop water from forcing into the system during operation. The electronic valves all seem to be too large to screw around with, too expensive, or altogether too much of a pain to install. If I had seperate draining pumps, I would literally only need to close the manual ball valve once a day, after the bags are full. I think I can deal with that.

Not a lot of response about a possible 2" thru-hull - nobody done that?

Etakk, before you start putting holes in your boat, I'd probably test out your manifold idea with an existing drain hole. I've made several manifolds and they never seemed to work 100% of the time. The pumps attached directly to the hull, like in my VLX, work every time.

Call me when you're ready to do the install and I'll come over to supervise and drink your beer