Notes

1.The first step is to find the breaking point of one solitary bag. Hang it on your coat hanger or whatever you found and begin filling it. Make sure the scale is underneath, as it will save you a little work later. At some point your bag will give in and break. Note where the bag fails. Was it the handles, or did the bottom fail first? While this is not what you are testing at the moment, it may help with future analysis of your data.
2.With any luck, when your bag failed the weights inside should have fallen to the scale. If not, just pick them up and put them on the scale (this is why sandbags or Ziploc bags with sand in them are recommended, as they're easily movable and shouldn't make a mess). Record the weight it took to break the bag, then do this same test with at least three more bags. This is to make sure that the bags break at some consistent weight range.
3.Once you've taken down the breaking weights of at least four single bags (and made sure that they're fairly consistent with each other!) you are ready to try double bags. Insert one bag into another so that the one is basically acting as a liner for the other, then hang both from your hanger over the scale. Again, fill it up until the bag breaks, record the weight, and repeat this trial for double bags at least three times.
4.After the double bags, try the same procedure at least four times for triple bags and quadruple bags. We encourage you to do as many extra trials as you need to feel completely satisfied with your data. You can even add more bags into the equation. Remember, the more data you take, the easier it will be to draw meaningful conclusions from the data.