WM bag overfill – any reason not to?

Only reasons are : It will make it heavier, and it will make it warmer.

depends on what you do in warmer weather if it will bother you there.

also, do you even need it if you are carrying clothing. Below 20-25 at night Ive got down jacket and pants and booties, and a 30F bag is fine.

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No reason not to for me. I have an Apache with the factory provided overfill and like the way the bags sits around me and lofts, both better than the standard fill bag that I checked out, IMO. You can also specify where the overfill is added, which can be particularly helpful if you suffer from cold feet.

I know this is BPL, but I am not a believer in a barely adequate bag and making up the difference with clothing. I like a bag which will be adequate for what I expect to encounter wearing only a light thermal top and socks.

I then have the option to add clothing if I encounter the unexpected. I think of this as insurance.

What does a retrofit of overfill cost? I guess it depends on how many ounces of down they add, but I would figure opening seams, adding 1-3 oz of down, and resewing must not be cheap.

I agree with stry. I've done enough of this to have figured out where I'm willing to carry a little extra weight, and a comfortable sleep system is where I'm willing to carry a bit of extra weight. If you can't sleep you're miserable- that's not "camping," it's "enduring." But then of course the question is ARE you miserable without the overfill? If you don't need it you don't need it.

I spoke to WM about overfilling my Kodiak recently and they reckoned it would add 5F for about 6oz weight gain, I decided against it as my Puma is only 10.5oz more.

Howdy,
I sent my 23.9 oz Megalite in for refill, and it came back 28 oz for $40. Good to go. Thanks WM.

stephan

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I think Stuart is asking whether it's worth doing to save himself
getting a warmer bag.

Mine cost $35 including return shipping three years ago. Two week turnaround. Thought they were adding three, but they added nearly six ounces. Workmanship is superb. Can't tell anything was done externally.

I think you are cheating yourself out of buying a 3rd Western Bag that is even warmer. That way you have 3 really cool bags, plus it is fun to buy outstanding gear.

Owner of 4 WM bags here, I absolutely love them.

As soon as I can get around to washing it, I'll be sending in my Summerlite for an extra 3 ounces. A friend had three added to his and I really liked the look of it.

The real question is, will adding overfill compromise the performance of these bags in any way? Sure, they'll weigh a few oz more, and they won't pack quite as small, but are these the only downsides? If so, then I see no reason to avoid having it done.

I always used to think of myself as a warm sleeper, but as I get older I wonder whether my metabolism isn't as efficient as it used to be. Either that, or I'm doing more cold weather trips than before. I bought the Alpinlite and the Kodiak for the extra space they have, and I have worn down parka (MB Mirage) / pants (WM Flight) / booties (WM Flash) inside to supplement the bag. I switched from an Exped Downmat to a TAR XTherm last fall, and don't feel any cold from the ground through the pad. But overall I felt cool at 15F in the Alpinlite this fall. Last weekend I was comfortable at 20F in the Kodiak on Friday night, but on Saturday night it fell to the low single digits and I felt cool. A month ago I was out at -5F and the Kodiak plus all my down layers was only just enough.

So yes, I am looking for more warmth, but I don't wish to switch to the narrower 10F Versalite and -10F Lynx. From what I've read, the overfill (4oz on the Kodiak, 3oz on the Alpinlite) will add about 5F to the temp rating. That's more efficient than carrying a ~15oz 50F synth quilt to lay over the bag that would add a similar amount of warmth. I figured the small upcharge on the overfill ($57 for the Kodiak, $45 for the Alpinlite) would be worth it, especially if I can avoid the shipping.

If the Alpinlite becomes too warm for summer use, there's always the Caribou…

You sound like the perfect overfill candidate. I myself have not noticed any downside to having had it done.

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I was planning on getting a couple ounces adding to my summerlite. I feel like that would hit a sweet spot for warmth for 3 season hiking. The summerlite seems a little limp like it could take a couple more ounces well.

I saw the overfill rate sheet on their pricing page, but i assumed that price was added to a new bag when they did it at the factory during production. Sound like those prices are for the post-sale mods. Cool.

I've always lusted after a Summerlite. I have a MH Speedlite 32 bag now that I actually am quite happy with, so I can't justify the switch. I just bought a used Summerlite for my wife though. Looks great for her.

Josh – The Alpinlite is a couple of seasons old, and it would probably have to be washed before WM would take it in for overfill. That might be just the ticket although I wouldn't mind adding 5F to its lower limit.

I bought the Kodiak in September, and I've only had three nights in it, all with baselayers. I don't think WM will ask for that to be washed given its limited use. That's the one I'll be taking in first. Overnight lows here are regularly in the +/- single digit range, and having a true -5F bag would be very handy. Much colder than that (like the -25F Puma) seems overkill for my 2-3 night winter trips.

Maybe arguably, the overfilled down is half as warm as fully lofted down.

Think about it – you want to fluff up the down so it produces as much loft as possible. If your sleeping bag is compressed, it won't be as warm.

If you overstuff, you can't get as much loft. You would do better to increase the baffle size a little.

If you add 6 ounces of overstuffed down, you could achieve the same warmth if you added 3 ounces of down and had wider baffles. That is, just get a bag rated for a colder temperature.

You want some overstuff because all the baffles won't be perfectly evenly stuffed, the down can get damp or absorb body oil and lose some of their loft.

It does feel better to be over-stuffed, but you pay a small weight penalty.

That makes sense Jerry. However, sometimes it seems like bags are underfilled relative to their shell volume.
Sometimes people want that extra warmth without buying a new bag and they don't mind getting a little less warmth for the weight.
A bpl guy I hike with was talking about adding some down to his well used western mountaineering bag because it had lost some of its loft over the years.

I would first ask this to myself: are the current bags warm enough for 95% of what you do now ? If so, overfilling the bags might make them to warm for the 95% of what you use them to. If that's the case, I wouldn't overfill and add clothing when needed. Otherway, overfilling might be a good route to go.

BTW, wearing clothing while sleeping is no problem for me. I already wear several pieces in camp. So when going to sleep, I just crawl in my SB with those pieces on (my SB is constructed to have more then enough space when wearing clothing) and I've never been cold, although the bag is only rated to 32°F and it might be 20°F.

PS: I've done the same with a bag rated to 10-15°F and the outsidetemperature was 0°F.

I have a WM Summerlite that I found to be marginally warm for me at mid to high 30's temperatures as purchased. At the lowest rated temperature (32) I would get cold in it. Because the Summerlite is a closely fitted bag, adding extra clothing was uncomfortable for me and tended to decrease the bag's loft and the insulation value of the clothing. I'm in my late 70's and my internal furnace isn't as hot as it once was.

I sent the bag back for a 2 oz overfill and now the bag is warm enough in the mid-30's and marginal at 32 degrees. To me, it was worth the $35 and the extra 2 oz of added weight. They did a beautiful job!

I prefer to sleep without wearing a lot of extra clothing if possible; I'm just more comfortable that way. So, I like to take a sleeping bag that will be warm at the lowest temperature I anticipate seeing without wearing my clothes to bed. My preference is to leave my puffy jacket behind and wrap my sleeping bag around me on cold evenings in camp to stay warm. I never wear a puffy when I'm walking.

like some others who prefer a bit more insulation …. ive come to the same conclusion

– these days if im cold i find i get sick easier … a case of the sniffles outside aint the most fun

– sometimes temperature drops are lower than you anticipated … a bit of a margin aint a bad thing

– unless you can dry it out in the sun, down can lose its loft from moisture overtime … a bit more insulation compensates for this

while the en-ratings are generally accurate for the "standard" eurobum …. folks come in all shapes and sizes and some run warmer/colder than others

interesting that so many folks are adding down to the summerlite … while its marketed as a 32F bag, it en-tests at ~35F for men

;)