DIY Ballast System w/ Diagram

I'm planning on installing an auto ballast system in my '97 Moomba over the winter. I'm going to use sac's in front of the rear seats and in the bow walkway because I don't have much storage (and don't want to loose what I have). Most of the system will be hard-wired and hidden. Then I'll just pull out the sac's with pre-attached hoses, connect them up to quick disconnect fittings, and flip a switch to fill. Here is what I'm thinking so far:



I have a few questions, and looking for any pointers if you've done this before.

(1) Are there quick disconnect fittings I can get and use with the clear plastic tubing most people use in these applications?
(2) Does this look like the right design and plumbing?
(3) Should I use a dedicated thru-hull fitting for pumping out the water, or just tap into the already existing one (for the bilge)?

Thanks

Looks pretty good. I just did a very similar system in my 97 MC. I used a dedicated thru hull for draining and that was with just one pump. The bilge line is a smaller diameter and would have definitely limited my drain times. With two pumps, you should probably have 2 dedicated thru hulls.

If you have any luck finding quick connects, I'd love to know about them. I used regular pipe fittings on mine.

Is everything hard-wired and tucked under seats on yours? Or do you have sacs out in the open?

Thanks for the advice on the thru-hull outlets.

The sacs are out in the open. It's a dd 205, so there isn't room to hide the weight. I have a 1200# couch in the back and a 750# sac in the bow/walkthrough.

Of course, those weights are total crap, unless the manufacturers somehow change the density of water as it passes into the sacs. The volume of the sacs simply can't contain that much weight.

The front sac has a quick connect that I pulled off the tsunami pump I was using. I have the hose under the front seat and pull it out to fill and drain the sac. The rear has a screw-on fitting that I connect to one of the bottom valves and I just leave that on all day. I can remove it when we're done so I can take the sac out of the boat.

The pump is under the spotter's seat and I have a manifold mounted on the inside of the gunwale to direct flow. It's a 3-way so I can fill the front, rear, and/or a side sac for surfing.

I see one problem. Your sacs have no means of burping. If you don't burp the bags they'll end up with air that can't get out before the bag even fills. You'd need another set of one way valves to allow air to escape from the bags.
You can also eliminate the drain plumbing and just have the sacs fill and drain out of the through hull fitting.

Chris
www.wakejunky.com

Sounds like a nice system. Almost exactly what I'm looking at doing.

Are you using manual lever-type valve's to direct flow? Also, is the one pump enough to fill up the sac's, or would more than one pump help speed up the process?

Any pics of your setup?

Thanks for the input.

Looks, good, you should put check valves on all lines though...

Dont rely on you pumps to stop water from enetring a bag upon an empty of another. You can take the check valve that you have labled and move that to the left of one of your pumps. Add another in the same position as your other pump and add one more to your bilge line so water from the emptying sacs will not find its way into your bilge...

another note, I do not burp my system at all. Did it once on the first fill and there is no air in the bags at all anymore...

I used a manual valve set up. It just wasn't worth the expense and wiring hassle for the cool factor of the actuated valves. Another pump would certainly speed up filling and draining. It would also mostly eliminate the need for the manifold. One pump is quick enough for me though, so I skipped the expense of another pump.

Wakejunky has a point about draining through your intake thru-hull. Then again, if you're doing 30 mph across the water back to the ramp or the dock, you're pumps are going to be working against a good amount of pressure.

So here is my updated diagram with a separate thru-hull fitting for each pump.

I'll try to get some pics for you this afternoon or tonight.

Are you mounting the pumps in the bildge? If not, then you can use Simer pumps for alot less money. One of the things I have done in the past is have the switch control relays that are mounted by the pumps. The wiring from the pump to the relay then gets wired to the battery connection on the starter solenoid at the motor. This keeps the heavy gauge wire as short as possible.

Here are a few pics.

Under the spotter seat:


The manifold:

IMO you are over complicating the system. You only need the water inlet which the pumps can also use to pump the water back out of. This will eliminate the need for all of the valves other than the main shut off. The impellers in the pumps will keep the bags from emptying on their own. With the Fly high pro-x series you can get quick disconnect fittings that go on the sacs.


Then run overflow out of the top of the sacs to through hull above the water line exits similar to where your bilge hose currently pumps out. This will burp the sacs and keep them from overfilling if you forget to turn off the pump. It is also easier on the pumps when the bag doesn't vacuum closed which happens if there is no vent.

I have been running a 3 pump system all filling and draining from the main fresh water pickup of the engine for 3 seasons now with zero problems. I can fill and drain at full speeds.

Ok, so here is a much simplified version of the system.



I'd use the thru-hull fitting (on the underside of the hull) for both pulling in water and pumping out water. I don't mind slowing down a bit while pumping out if pressure becomes an issue.

I'd put vent fittings on the Fly High sacs for venting and in case of over fill. I have a direct drive, so these sacs will be sitting out in the open. I don't see a need to plumb a line to the overflow on the sacs. If I forget to turn off the pump, I'll see water coming out of the valve and thus shut off the pump.

I will also definitely use relays to activate the pumps. Just didn't put them in the diagram for simplicity.

That looks a lot nicer. Adheres to the KISS method nicely. The less stuff you have the less there is to go wrong with.

Here is a site that might be handy for the Quick Disconnects:

https://www.flow-rite.com/store/marine/retail/marinestoreretail.html

look under 3/4" Fittings; there is less selection in the 1 1/8" section

also for the plastic thru-hulls for above water side discharge if you go that route

I used garden hose quick connects. they work very well, and they are a lot cheaper.@ home depot I think you get 2 for 1.99

Will those 3/4 quick connects take the place of a waterbed fitting?

yep!