Overbag Moisture Management

In cold winter conditions and very moist conditions, using a synthetic over bag on top of your down bag is a really great way to keep your down dry. Synthetic insulation like Climashield Apex and Polartec Alpha Direct deal with moisture very well. Down does not. Even modern treated down. In cold conditions a scenario is created that over time will wet out a down bag even if outside all the moisture is locked up as ice and snow. When you sleep in a sleep system your body is expelling moisture constantly. Quite a bit actually. If it is warm, the moisture just moves on through. When it is cold, the moisture will collect on the first cold surface it reaches. Unfortunately the first cold surface is going to be at some point inside the down fill of your sleep system. If you put a synthetic overbag overbag over your down, that dew point gets pushed out of the down and into the Climashield or Alpha Direct where it can be removed from the down. From this point the overbag can be dried during the day, or it can be packed away separately. This keeps the down system dry and then when the moist overbag is re-installed the next night, your body heat continues to hold the dew point away from the down, in the synthetic. At some point the moisture in the overbag will need to be dealt with but it will be much easier to deal with here, in the synthetic insulations that dry fast, than in your down insulation that does not. Additionally, in really wet conditions it is almost impossible to stay dry just from dew and blowing precipitation. A synthetic overbag will catch all that incoming moisture too. These insulations will continue to keep you warm when it is wet and they dry fast.

Timmermade Overbags also double as an insulated poncho just by opening the footbox and securing it around your shoulders. This again provides an opportunity to carry gear that has more than one purpose, either as a safety net or so you can go ultralight and maybe leave the jacket at home….or carry a lighter one.