Do I need a microfiber sleeping-bag shell?
This July I climbing Mount Rainer. My climbing partners have told me that a synthetic bag is necessary because of the rain. They recommended a 25- to 40-degree bag. We are going light and fast, and plan on using open-air bivys, so I think a bag with a microfiber shell would be a good thing. Unfortunately, I not having any luck in my search for the perfect bag. I have stumbled on only a few bags that are synthetic and have microfiber shells. Integral designs makes one, but it uses Primaloft2 as its insulation material. I have been warned to stay away from short-staple fibers because the bags don't last very long. Do you have any suggestions? Mike Ads Newark, Ohio
Tell you’re climbing partners they’re full of it, Mike. And read my lips: “It…doesn’t…rain…on Mount Rainier….in July.” At least not often. Despite Washington State’s wet reputation, the simple fact is that we are in a drought from about June 15 through October 15. Yes, the odd storm will sweep through - one hit mid-July last year and lasted a week - but that’s the exception, not the rule. In any event, any big storm also will be a big COLD storm, so you will have snow at 10,000 feet and up, not rain.
So here’s the deal: One, either a down or synthetic bag will be fine. Get one rated to between ten and 20 degrees. And you should be OK with open-air bivys. I guess I’d recommend a light bivy bag, whether using a down or synthetic bag, just because the extra shelter could come in handy.
Two, check the weather forecast, and don’t be shy about packing a tent if it’s marginal. Rainier is a big, Alaskan-style mountain, one that creates its own weather. And while my bet is that conditions will be fine - clear and sunny, with high winds above 12,000 feet the worst problembig storms can hit.
As for synthetic-bag durability, it’s true that short-staple fibers such as Primaloft supposedly do not last as long as long-staple fibers such as Polarguard. But in reality, good manufacturing goes a long way toward overcoming this problem. Integral Designs bags are fine. A good one for your trip would be the North Twin ($220), a really nice, ten-degree bag.