My Sacs are Bulging

[chpthril]

A couple of things to point out. Pressure, measured in pounds per square inch, is a result of force and resistance. If you have no resistance, you have pressure. The sacs are bulging, thus applying unwanted force on the boat, because they are not vented.

So, if I'm understanding Ragboy's dilemma correctly, he needs the sac to bulge in order to get as much weight out of it as possible, and this is done by using a spring loaded c/v. But the bulging and pressure is now reeking havoc on the boat. Kinda a catch-22, huh.

Well, I hate to say it, but I gotta go back to my original suggestion of going with the original Enzo sac. Because the sac is larger then the storage area, it will fill almost every in. of the storage area, giving the maximum weight possible. When vented, the sac will not build pressure and bulge, thus no undue stress on the boat, but will fill as full as the storage area will allow. Kinda like putting a 55gal trash bag in a 30 gal trash can, it still holds 30 gals, but the sac will fill the entire can and not leave any voids. No added stress to the can, unless you overfill the can and then try to force the top down compressing the trash

[ragboy]

couple things.

1. I did order them smaller, but didn't think the bulge would be THAT pronounced. They key will be getting the size just right.

2. @chpthril I respectfully disagree. The sacs fill from bottom, water seeking its own level and all. In order to COMPLETELY fill the rear, the front has to fill FIRST, because it is lower than the rear. You can see that clearly in pictures with RJ. So in order for the upper half of the rear of the sacs to fill, the front must pressurize to the point where water can then fill the upper half of the sac. And the amount of pressure on the front grows til you see cup holders starting to pop, you seat lift up, and fiberglass is getting that strain. When the rear of the sac is finally full, the greatest amount of pressure is on the front of the sac, where you have more sac than space. You can't fix the problem in this area with a smaller sac, unless you go so small that you make the back very thin, and waste a lot of space, and lose the weight.

[majestic]

My 1000lb sac is on the way soon, I hope to not have any of these issues. If I see fiberglass damage or other I will have a sac for sale and will go smaller.

[dogbert]

A couple of things to point out. Pressure, measured in pounds per square inch, is a result of force and resistance. If you have no resistance, you have pressure. The sacs are bulging, thus applying unwanted force on the boat, because they are not vented.

So, if I'm understanding Ragboy's dilemma correctly, he needs the sac to bulge in order to get as much weight out of it as possible, and this is done by using a spring loaded c/v. But the bulging and pressure is now reeking havoc on the boat. Kinda a catch-22, huh.

Well, I hate to say it, but I gotta go back to my original suggestion of going with the original Enzo sac. Because the sac is larger then the storage area, it will fill almost every in. of the storage area, giving the maximum weight possible. When vented, the sac will not build pressure and bulge, thus no undue stress on the boat, but will fill as full as the storage area will allow. Kinda like putting a 55gal trash bag in a 30 gal trash can, it still holds 30 gals, but the sac will fill the entire can and not leave any voids. No added stress to the can, unless you overfill the can and then try to force the top down compressing the trash

I have that situation with my bow sac and it bulges

[ragboy]

I think I may pull my boat in this weekend, and do some tests.

[dtown]

You guys need lead bricks. No bulging, no plumbing... no problems. I made these 25lbs bricks last winter. If you can lift 25lbs you can easily move 20 of these bricks from one side to the other in 5 minutes. Bonus is that you don't lose your storage area! I painted them up with roll on truck bed liner. I made extras that I'd sell. PM me if interested.

[ragboy]

That looks like a terd with a string on it. Need to put some gold in that mix, so it looks like corn. LOL. j/k.

There are few reasons why I don't use lead/pop bags anymore.

1. You feel it when you tow 700-800 lbs of lead is a lot of extra weight.

2. My boat is now on a lift, and when I had the pop bags in there, it barely lifted, removed them, it lifts with ease.

3. My previous side to side issue. One of the things I have learned as a dad, is you have to keep the kids stoke up. This is why we do contests and videos and wake9, makes it fun and exciting. Nothing puts a dent in that like moving everything around to move bricks. The bricks need to go under the sac. you have to empty side sac, remove sac and anything on top like jackets or whatever. then empty other side and put lead on bottom, then put sac on top and fill, and put all away. Its a PITA IMHO. Not bad if you do once in a while, but we do every time we go out, and we go out 3x a week.

Now go to our system now, you move some life jackets and flip 2 switches. One fills and one empties at same time, we all go in and swim, listen to tunes and horse around for 15 mins or so.

The extra effort to get it to work this way, automated with all H2O is important and worth it to me.

[dogbert]

You guys need lead bricks. No bulging, no plumbing... no problems. I made these 25lbs bricks last winter. If you can lift 25lbs you can easily move 20 of these bricks from one side to the other in 5 minutes. Bonus is that you don't lose your storage area! I painted them up with roll on truck bed liner. I made extras that I'd sell. PM me if interested.

LOL...every time I hear someone recommending lead bricks I think of my friend who owned a Supra. When his kids were old enough to take the boat out, they just pick up rocks from the shoreline and used those.

[dogbert]

Now go to our system now, you move some life jackets and flip 2 switches. One fills and one empties at same time, we all go in and swim, listen to tunes and horse around for 15 mins or so.

The extra effort to get it to work this way, automated with all H2O is important and worth it to me.

I'm still waiting to be adopted...LOL

[dtown]

I didn't eat any corn!

True true.
... just tell the kids that this is the new weight training program. haha

Fully automated is nice.

[dtown]

Ballast systems are something that manufacturs are going to have to look at harder as this mussels issue gets worse and worse (see Timmy!'s thread). The fully automated Pure Vert System seems like the best ballast system with regaurds the mussles issues. http://www.mikemurphyentinc.com/purevert.html
That's the main reason why we switched over to MB for our new boat... Colorado is getting crazy about mussels... not a bad thing.

The problem with the Pure Vert is that the weight is spread across the whole side of the boat (great for wakeboarding) rather than the rear locker area. This is why we use a little lead in the rear locker.

[zad0030]

Pure Vert = Pervert lol

[dtown]

If

Pure Vert = Pervert lol

Then
slalom,trick,jump = ankle grabber j/k j/k

[Ptown]

Ragboy, sounds like you are on the path of what I would have recommended which is making the sack under the seat it's own compartment. This would be the best way to reduce the sloshing affect. By the way, sloshing is an actual term used in fluid dynamics. When designing water tanks in earthquake country, you have to take into account how much force will be hitting the roof of the tank during an earthquake due to the side to side movement. If you are worried about the pressure when the sacks are filled and stationary, then you have a couple options. First would be to make the sack under the seat it's own copartment. This allows that part of the sack to be filled without the added pressure from the rear locker due to the extra height. Other option would be to order a smaller sack so that the sack is completly filled without touching the fiberglass. This would make it so the water pressure is felt on the sack rather than the fiberglass. This would probably make the sloshing affect worse though. The option that would allow the most water in the boat with the least amount of fiberglass stress would be to reinforce the fiberglass though.

[ragboy]

yes, we are working on 2 sacs per side. The issue is connecting them, and then emptying properly. They fill easy. We are working it out. We are on the job. ;-)