Fat Sac actual weight?

[GuitsBoy]

I have heard that fat sacs are overrated, but by how much?

I didnt realize until i saw my old 18 gal rubbermaid containers I had used for ballast before I got my locker sac. It looks like two rubber maid containers would hold more water than the locker sac does. Why is the locker sac rater at 600# when I know that the two rubbermaids will hold less than 300#. Are fatsacs really rated at 200% of what they actually weigh? I guess what I really need to do is measure how much water is really in them with a gallon jug and do the math. I guess thats why 600 real pounds made a much bigger wake than the 600 pound fat sac. And here I though I just needed to work on positioning and trim!

[Nauty]

The ratings that fat sac companies state vary from manufacturer to manufacturer. Some understate the full capacity and some overstate it. Basically, to determine the weight of a rectangular sac you can use the following formula:

Length x width x height x .036 = weight

Therefore, a sac that is 42 x 19 x 19 would technically weigh 545 lbs. However, this would be if the sac filled up exactly to its seams and did not stretch past them. Most sacs, when completely filled, stretch quite a bit past their seams. In the case of the 42 x 19 x 19 sac mentioned above, it is not unreasonable that to think that this sac may stretch a couple of inches to 45 x 22 x 22 making it weigh somewhere in the neighborhood of 745 lbs.

Like I said, which weight the manufacturer decides to market varies. Some manufacturers want to advertise the largest weight possible thinking it will help sell the sac. You will notice that most boat dealers advertise the lower weight on their stock ballast systems (if a sac is used) to help keep them from violating the capacity plate for the boat they are selling.

Long story short, if you want to know the exact amount of weight your sac will hold, fill it up completely and then drain it into 5 gallon buckets. Count how many gallons come out of the sac and multiply them by 8.33. A gallon of water weighs 8.33 lbs. Then you will have your exact answer without debate.

[GuitsBoy]