What is a ballast sack - Puzzle Toys

I recommend washing it by hand with warm water. It is easy to do, it dries quickly, and in a washer you are putting the sack more at risk of ripping or causing a little hole which will result in the sack no longer being waterproof.

Basically, just stuff the sleeping bag into the sack while rotating the sack slightly with each 'stuffing' to make sure you fill all the nooks and crannies. Then close the flap, over the opening, and cinch the straps as tight as you can. You can check out this video: http://www.youtube.com/watch?v=GolE9gg3GRo

Airpurge means the sack is made of a high quality waterproof fabric that allows air to escape freely from inside the sack when you are compressing it, without letting water or air in from the outside. This is helpful because the entire goal of using a compression sack is to get the air that is trapped inside your lofty sleeping bag out. that is how the compression sack is able to make the size smaller, and airpurge makes it all easier.

Your sleeping bag is usually sold with a stuff sack, which just refers to the (usually nylon) bag that the sleeping bag comes in. If space in your backpack is not an issue, than the provided stuff sack will be fine for you, but keep in mind that it is not totally waterproof because water can enter in through the opening at the top. A compression sack is a separate sack that you can buy if you want to pack your sleeping bag into a smaller size. The compression sack shrinks the size by allowing you to use straps to squeeze any excess air out of the sleeping bag. The straps are connected to a piece of fabric that can cover the opening of the sack and make it completely water-proof.

You should try to avoid this for several reasons. First, it will make your sleeping bag stink and potentially become moldy, as well as the inside of the compression sack. Next, it may reduce the warmth rating of your sleeping bag because moisture will become trapped inside the fabric. Finally, it defeats the purpose of having a waterproof sack if you put something wet inside of it. If your sleeping bag is caught in the rain and you don't have time to hang it out before hitting the trail, try to take it out within a few hours and get it dry. You can also flip the compression sack inside out and let it dry, it will dry very quickly.

There is a 'roll top lid' that covers the opening. After shoving your sleeping bag inside the sack, you place the lid over the opening. The lid has 4 straps that are connected to the bottom of the sack. Once the lid is in place, pull the 2 opposite straps at the same time. The lid is made out of the same waterproof fabric as the rest of the sack, sometimes it is even double insulated because it has more stress put on it. As long as you make sure the lid covers the entire opening, no water will be able to get in.

No, but leaving the sleeping bag inside a compression sack for an extended period of time will reduce the loft of the sleeping bag. In between camping trips I suggest to take the sleeping bag out of the compression sack. Also, when stuffing the sleeping bag into the sack, try to do it evenly on all sides to not wear out the stitching.

Generally, no. It is possible that you could find a fire resistant compression sack but that is not the standard.

It is ok to put your compression sack in the wash but it should be on a delicate cycle. They tend to get pretty stinky if you've been camping so it's helpful to have the option.

Yes. Most have two or three to tighten whatever is in the sack and to attach it to another bag for easy carrying.