Sleeping Bag Rating?

11:22 p.m. on May 21, 2006 (EDT)
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19 forum posts

I recently stumbled upon a used down mummy sleeping bag that I cannot find anything about. The only marking I could find on it was on the “do not remove under penalty of law” tag. It says that the sleeping bag was made for the Sears Corporation. It is slightly used and faded but otherwise it is in good shape. Is there anyway I can figure out what temperature rating the bag would be good for or should I just forget using it all together?

4:49 p.m. on May 22, 2006 (EDT)
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6,010 forum posts

Temperature rating is only a rough guide, plus various companies use different methods of rating the temperature range. A few of the top companies, which tend to make very expensive bags for the intended use, are pretty accurate, but way too many companies, especially the ones making the bags for the mass market (like Sears, Big 5, etc) tend to over-rate the bags.

The general rule of thumb that works for the "average" backpacker is to measure the loft of the bag. To do this, get the bag out and fluff it up as much as you can, then let it sit for a bit to build its loft. Several things that will affect the amount of loft - how long it was stored stuffed or rolled in its backpacking bag (bags should be stored unstuffed), how long it has been sitting out (to allow the filler to rebound), how recently it was washed (dirty bags tend to not reach their full loft), how it was washed (never, never, never dry clean a bag - removes the oils from down fill, and the cleaning fluid is poisonous to breathe - use "soaps" which are intended for washing filled bags and clothing).

Having let the bag fluff up, lay it out flat, as you would use it for sleeping (zipped closed). Now measure how thick it is. The minimum temperature you can use it without supplements depends on lots of things, but generally 3 inches will get you to freezing, 5 inches to the 15-20F range, and 8-10 inches will get you into the -30 to -40F range.

Some assumptions here - you are using a sleeping pad with appropriate insulating qualities (closed cell foam, or an inflatable with interior insulation, such as foam, down, or Primaloft). You are wearing sleeping clothes that are dry and appropriate to the temperature range (T-shirt and shorts for summer weather, light long johns for subfreezing weather, expedition long johns for subzero weather). You are in an appropriate shelter (in the open for summer, in a tent for +50F down to subfreezing, in a 4-season expedition tent in subzero weather). If you are really fatigued, dehydrated, haven't eaten a good dinner, etc, your bag should be quite a bit warmer. It also matters in a tent if you are alone or with 1 or more companions who can add to the heat generation in the tent.

5:07 a.m. on June 14, 2006 (EDT)
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18 forum posts

GO to the manifactures web site and see if you can find it there. Otherwise sleep in it

5:08 a.m. on June 14, 2006 (EDT)
42 reviewer rep
18 forum posts

BTW if made by "Sears" dont bet your life on the bag.

June 19, 2018
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