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  • Adding ports to Ballast bags


    cowwboy
    • Year: (unspecified) Brand: (unspecified) Cost: $0-$249 Ballast Modifications: Fat sac(s), Fittings DIY or Professional Install: I installed it

    Before you could get custom bags made from wakemakers I was stuck with 3/4" fittings.

    So I decided to add 1 1/8" fittings to my bags for a reversible pump.

    I planned on using the flow-rite through hull fittings with RTV silicone added to ensure a leak free seal.

    Here is the fitting I used. https://flow-rite.com/products/marine/1-18-fittings/ma-044-qlb

    I hooked up a air pump to ensure it would stay inflated so I could work with the bag. 
    I then drew out the hole needed for the port to go through but left it a tad on the small side.
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    I then used a new razor blade to carefully cut the hole out.

    553698_10151194295818245_341593246_n.jpg.d0b245dd7d4c4cbea990e0d95b7310ba.jpg
     

    I then pushed the mushroom end of the fitting through the bag after putting a liberal coating of rtv on the edge of the fitting that would mate with the bag.

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    Then just put the nut on and tighten down.

    377124_10151194299588245_1805145708_n.jpg.dba30320a1f92b2ec2c2ea9143c3b571.jpg

     

    Definitely measure 4 times cut once. It was almost as unnerving as drilling hole through the hull. 

     



    User Feedback


    Nice project... I have a few bags that lost their ports (Wakemakers replaced them), so maybe I can salvage them like this.

    Should be a big improvement with less friction loss / restriction on the new port!   

    Have you tested it yet with it full of water?

     

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    3 hours ago, Rugger said:

    Should be a big improvement with less friction loss / restriction on the new port!  

    Its a little gain in flow rate between the 3/4 fitting an 1" in a standard 3/4 threaded fitting, but not huge. Maybe like 12 seconds difference on a 400 lbs sac. Just note, this is with an aerator pump. Impeller pump will not be any different. Smaller fitting just increases the velocity, but flow rate remains the same. I would not add a fitting just in an attempt to gain a little flow rate. Rather for the need for an additional fitting or one in a different spot.  

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    1 1/8" vs 3/4" is substantial in hydraulics.   But yes, these aren't high GPM pumps.   

    But....15-30 seconds is a long time to wait when it's your turn to go first. :)   haha

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    14 minutes ago, Rugger said:

    1 1/8" vs 3/4" is substantial in hydraulics

    While thats true, those are the nominal ODs of the fittings, not the true IDs. Back when I did my testing, the threaded sac size was the 3/4 thread opening by fly high. We did not yet have a 1" threaded opening we see on the strightline and WM sacs. The ID difference between the fly high 3/4 (.525 ID and 1" (.735 ID) was noticeable, but not huge. No real difference between 3/4 and 1" hose though. The difference came from the fitting upgrade, not the note. Yes, I made 3/4 hose fit over the 1-1/8 fitting for the test. 

    I would presume that the 1" threaded fitting or the flow-rite thru-hull would show a little increase over the .735" ID fly high fitting, but not enough for me to cut a hole in the sac. 

    Again this is all based on aerator pumps. Positive displacement impeller pumps dont really benefit from this. They are not effected by head pressure near to the degree as aerators. Once the flow hits the narrow sac fitting, the speed of the water increases and the GPH in to the sac stays about the same. 

    I also like to use a PVC/Rubber cement when bonding in these added fittings. Use some on both the flange and the jam nut on the outside. I also like to use the straight thru-hull with a 90* quick-con on the hose. This allows the hose to move without pushing on the glued in fitting. 

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    Given I have not run a pressure  test on a ballast system to know the exact back pressure. 
    But on a jabsco ballast puppy going from 5'(2PSI) of head pressure to 20'(8.7psi) of head pressure you have a 16% drop in flow. 
    Plus the more you strain the pump the higher the current draw and load on the rocker switch. 

    My main reason for initially doing this was I added impeller pumps in addition to the existing aerators and no one offered custom bags except water bed bags at that time.
    If WM was making bags at that time I would have probably ordered them pre made.

    But when nothing is available you create what you need. 
     

    Also remember this is not even a 1" threaded fitting but a 1 1/8 ID. 

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    6 hours ago, cowwboy said:

    Also remember this is not even a 1" threaded fitting but a 1 1/8 ID. 

    Actually, the ID at the quick connect opening of the flow rite is .92. Thats not even the narrowest portion of that fitting. Inside of the flange, the fittings narrows down to .835". 

    The 1" threaded fitting that the wake maker, ronix  and straightline sacs use, has an ID of .965". 

    Maybe this off season, i need to do some more pump testing. Put an amp clamp on the pump leads and measure current while filling into the bottom of a sac and see if it changes as the sac gets full. Also compare a short and long hose. I can also time the fill rate into the top of a sac, then time again into the bottom and see what kind of difference head makes in the real world.   

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    Great idea and we can start a topic on ballast flow tests in Shop Talk / ballast section.    I planned on taking a few before and after flow measurements as well when I update my ballast and would love to hear more about your findings.

    For now, let's keep this this thread open for more questions about this ballast bag port project.   Thanks again, Cowwboy for the post.   I might have more questions if I fix those older bags with a broken fitting.

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