compression sack for sleeping bag, help with calculations please

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sil2017
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compression sack for sleeping bag, help with calculations please

Post by sil2017 » Sun Dec 31, 2017 2:29 pm

I have spent two hours searching, calling and trying to figure out which sea to summit compression sack I need to buy.
I am so frustrated and losing patience figuring this out so I hope someone can help me.

I have a North face Cats Meow sleeping bag. It is regular length with 1 pounds 9 ounces of filling (poly guard 3d-also known as polyester). It is rated at 20 degrees. Bag is 15 years old. North face still sells cats meow but may have a little more filling.

I am hiking Mt. Kilimanjaro within a month and I like to have my sleeping bag in a compression sack. I have read that sea to summit has the best sack.

I don't know what the liter should be for my sleeping bag. I called North face and I was told that the North face cats meow stuffing sack has 22.9 cm by 40.6 cm volume. CSR and supervisor couldn't calculate the size of compression sack.

Can someone please help me find the correct litre? It comes in 3, 5, 6, 10, 15, 20 . And do I need a water resistant or waterproof stuff bag?

Also, I have a woman nuptse down jacket size small. How big should compression sack be? 3 , 5 litres or??

Thanks very much.

livesoft
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Re: compression sack for sleeping bag, help with calculations please

Post by livesoft » Sun Dec 31, 2017 2:36 pm

I've seen some folks not even use a stuff sack since their pack works fine.

You won't need a waterproof stuff sack if you use a trash compactor (2 mil) plastic bag inside the stuff sack. But you certainly don't want you bag to have even a chance of getting moist.

A cylinder 23 cm in diameter and 41 cm long has a volume of pi *11.5*11.5 * 41 cubic cm which is about 17 liters.

Your puffy should stuff into one of its own pockets. You can try to use a 1 gallon (about 4 l) milk jug to see if it will stuff into that. My puffies would stuff into less than 2 liter, so you can try to cut off a 2 liter soda bottle and stuff your jacket into it to see what I mean.

A similar method can be used for your sleeping bag: Stuff your bag into something like a bucket and then measure the volume of the used part of the bucket.
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Mickey7
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Re: compression sack for sleeping bag, help with calculations please

Post by Mickey7 » Sun Dec 31, 2017 3:04 pm

If you have an REI store near to where you live, go there for help. You should be able to physically try it out,

Enjoy the trip.

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CAsage
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Re: compression sack for sleeping bag, help with calculations please

Post by CAsage » Sun Dec 31, 2017 3:22 pm

Agree with prior poster, this is one of those cases where I would buy a couple, try them out, return what you don't want. I suspect "stuffing" capacity varies so much with the compressibility of the item and the strength of the user and bag..... REI or any sporting goods store if you want to try this out in store!
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Re: compression sack for sleeping bag, help with calculations please

Post by Carefreeap » Sun Dec 31, 2017 6:23 pm

I have a Cat's Meow sleeping bag that I bought two years ago. It came with its own stuff sack. I checked the inside label and it says 10"x18".

Agree with the poster who said one of your jacket pockets should ask as its own stuff sack. I once had to google the jacket name to find out which pocket was designed to be the stuff sack. :oops: It isn't always obvious.

Good luck on your adventure! I had to bag on a trip to climb Mt. Kenya due to the terrorism act in Nairobi a couple of years ago so I'm cheering you on. :beer

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Re: compression sack for sleeping bag, help with calculations please

Post by TravelforFun » Sun Dec 31, 2017 7:12 pm

livesoft wrote:
Sun Dec 31, 2017 2:36 pm
A cylinder 23 cm in diameter and 41 cm long has a volume of pi *11.5*11.5 * 41 cubic cm which is about 17 liters.
Ha. I checked livesoft's calculation and it's correct.

TravelforFun

livesoft
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Re: compression sack for sleeping bag, help with calculations please

Post by livesoft » Sun Dec 31, 2017 7:19 pm

Plenty of youtube.com videos with good answers.

https://www.youtube.com/watch?v=6AnokcB371w

And even on Kilimanjaro: https://www.youtube.com/watch?v=WEMjrTS9TSA
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Re: compression sack for sleeping bag, help with calculations please

Post by cherijoh » Sun Dec 31, 2017 7:59 pm

TravelforFun wrote:
Sun Dec 31, 2017 7:12 pm
livesoft wrote:
Sun Dec 31, 2017 2:36 pm
A cylinder 23 cm in diameter and 41 cm long has a volume of pi *11.5*11.5 * 41 cubic cm which is about 17 liters.
Ha. I checked livesoft's calculation and it's correct.

TravelforFun
If you can't find a compression sack to test, another way to check it would be to see if you can stuff your sleeping bag into a daypack. They usually provide the capacity in liters. Checking the REI website, there are daypacks starting around 18 liters and running up to 40 liters. Based on Livesoft's calculation, it sounds like you are either looking at the 15 or 20 liter compression sac, so stuffing it in the smallest daypack may give you the answer you need. You can probably find daypacks at any big box sporting goods store if you aren't located near an REI or Cabellas.

sil2017
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Re: compression sack for sleeping bag, help with calculations please

Post by sil2017 » Wed Jan 03, 2018 9:54 pm

Thank you all . I bought 2 sea to summit event dry compression sacks.

nerdymarketer
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Re: compression sack for sleeping bag, help with calculations please

Post by nerdymarketer » Thu Jan 04, 2018 2:50 am

Please don't use a compression stuff sack, it can permanently reduce the loftiness of the bag, thereby reducing it's warmth.

More details: https://backpackinglight.com/forums/topic/57909/

halfnine
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Re: compression sack for sleeping bag, help with calculations please

Post by halfnine » Thu Jan 04, 2018 4:46 pm

Before moving on to the compression stuff sack, I am curious about a 20F bag for Kili. Most people likely opt for a sleeping bag in the 0F range.

livesoft
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Re: compression sack for sleeping bag, help with calculations please

Post by livesoft » Thu Jan 04, 2018 4:58 pm

A 20 deg bag could work with the right sleeping pad and the right night-time clothes.
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Pajamas
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Re: compression sack for sleeping bag, help with calculations please

Post by Pajamas » Thu Jan 04, 2018 4:59 pm

nerdymarketer wrote:
Thu Jan 04, 2018 2:50 am
Please don't use a compression stuff sack, it can permanently reduce the loftiness of the bag, thereby reducing it's warmth.

More details: https://backpackinglight.com/forums/topic/57909/
That is usually considered to be a problem for down fill more so than synthetics like in the bag being discussed. Synthetic fill is less compressible than down but is not damaged as much by it. (Something like a hot drier or being too close to a fire is much more of a danger for synthetic fill than compression.) The exact fill used in the Cat's Meow has changed over the years.
halfnine wrote:
Thu Jan 04, 2018 4:46 pm
Before moving on to the compression stuff sack, I am curious about a 20F bag for Kili. Most people likely opt for a sleeping bag in the 0F range.
I wondered about that, too, when I saw this thread yesterday. Apparently this bag has a fairly accurate temperature rating, unlike many that greatly exaggerate. I think that there is a good chance that sil2017 will end up sleeping fully clothed in the bag. I would also consider getting a silk liner and making sure that my sleeping pad provides a good bit of insulation if I didn't want to buy a warmer bag for that hike.

I use a regular waterproof stuff sack to slightly compress a down bag when backpacking but store them uncompressed. I would not use a compression sack for a down bag, but it might be necessary to use one to get much compression for one with synthetic fill. On the other hand, the amount of compression might not be worth the weight.

In this situation, where the temperature rating is at best borderline for the hike and volume is a problem, I would strongly consider buying or even renting a down bag.
Last edited by Pajamas on Thu Jan 04, 2018 5:20 pm, edited 1 time in total.

halfnine
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Re: compression sack for sleeping bag, help with calculations please

Post by halfnine » Thu Jan 04, 2018 5:06 pm

A 20 deg bag could work with the right sleeping pad and the right night-time clothes.
I agree there are a lot of ways a 20F bag could work under the right circumstances. I used a 38F bag on Kili and still kept all my fingers and toes :D . But, most people seemed a lot happier with lower rated sleeping bags especially since many are quite exhausted at the high camp. YMMV

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Re: compression sack for sleeping bag, help with calculations please

Post by Pajamas » Thu Jan 04, 2018 5:17 pm

halfnine wrote:
Thu Jan 04, 2018 5:06 pm
But, most people seemed a lot happier with lower rated sleeping bags especially since many are quite exhausted at the high camp. YMMV
When I was trying to decide on which bag to buy for the first time and had the choice down to temperature rating only, a friend told me that if you are cold, you can't sleep, and if you can't sleep, you can't hike. If you are too warm, you can always unzip the bag. I went with the bag rated for lower temperatures and did not regret it.

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Re: compression sack for sleeping bag, help with calculations please

Post by livesoft » Thu Jan 04, 2018 5:24 pm

Maybe the OP sil2017 can comment on their experience with their bag and temperature.

I've done quite a lot of backcountry wilderness snow skiing and camping in the Sierras and elsewhere. I love the cold and maybe they do, too. They may have plenty of experience sleeping while wearing down (or synthetic) filled booties, a puffy jacket, long underwear, beanie, and gloves. And they may already know to put their boots/shoes in their sleeping bag so that they are not frozen stiff in the morning and cannot be put on.

What are the coldest temps on this trip anyways? OK, I guess I can go watch numerous youtube videos and see for myself, nevermind.

See also: https://www.youtube.com/watch?v=Cn9sS7psIQ4
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Re: compression sack for sleeping bag, help with calculations please

Post by White Coat Investor » Thu Jan 04, 2018 10:47 pm

sil2017 wrote:
Sun Dec 31, 2017 2:29 pm
I have spent two hours searching, calling and trying to figure out which sea to summit compression sack I need to buy.
I am so frustrated and losing patience figuring this out so I hope someone can help me.

I have a North face Cats Meow sleeping bag. It is regular length with 1 pounds 9 ounces of filling (poly guard 3d-also known as polyester). It is rated at 20 degrees. Bag is 15 years old. North face still sells cats meow but may have a little more filling.

I am hiking Mt. Kilimanjaro within a month and I like to have my sleeping bag in a compression sack. I have read that sea to summit has the best sack.

I don't know what the liter should be for my sleeping bag. I called North face and I was told that the North face cats meow stuffing sack has 22.9 cm by 40.6 cm volume. CSR and supervisor couldn't calculate the size of compression sack.

Can someone please help me find the correct litre? It comes in 3, 5, 6, 10, 15, 20 . And do I need a water resistant or waterproof stuff bag?

Also, I have a woman nuptse down jacket size small. How big should compression sack be? 3 , 5 litres or??

Thanks very much.
I've owned at least a dozen stuff sacks in my life. Both a 20 degree down bag and a very beefy down jacket each fit inside the smallest compression sack that is generally sold. You'll need a bigger size for a -20 degree bag. I think your synthetic bag will also fit in the small size.

I see the Sea to Summit offers 5 sizes though, not just small medium large. And at REI they're measured in liters. If I was buying one for your bag and jacket at REI right now, I'd buy the 10L for the bag and the 6L for the jacket. I'll be surprised if those aren't perfect for you.

When in doubt, buy the next size up. It's not a big deal.

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Backpacking
Gear Capacity (L)
6 L: 6 liter
10 L: 10 liter
14 L: 14 liter
20 L: 20 liter
Gear Capacity (cu. in.)
6 L: 366 cubic inches
10 L: 610 cubic inches
14 L: 854 cubic inches
20 L: 1,220 cubic inches
Closure
Drawcord
Compression Straps
Yes
Material(s)
Cordura nylon
Dimensions
6 L: 5.5x14 inches
10 L: 7x16 inches
14 L: 8 x 18 inches
20 L: 9x20 inches
Weight
6 L: 2.4 ounces
10 L: 2.6 ounces
14 L: 3 ounces
20 L: 3.3 ounces
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Re: compression sack for sleeping bag, help with calculations please

Post by White Coat Investor » Thu Jan 04, 2018 10:50 pm

nerdymarketer wrote:
Thu Jan 04, 2018 2:50 am
Please don't use a compression stuff sack, it can permanently reduce the loftiness of the bag, thereby reducing it's warmth.

More details: https://backpackinglight.com/forums/topic/57909/
You must take less stuff backpacking than I do if you have space to not use compression sacks for clothing and sleeping bags.
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Re: compression sack for sleeping bag, help with calculations please

Post by Epsilon Delta » Fri Jan 05, 2018 12:39 am

White Coat Investor wrote:
Thu Jan 04, 2018 10:50 pm
nerdymarketer wrote:
Thu Jan 04, 2018 2:50 am
Please don't use a compression stuff sack, it can permanently reduce the loftiness of the bag, thereby reducing it's warmth.

More details: https://backpackinglight.com/forums/topic/57909/
You must take less stuff backpacking than I do if you have space to not use compression sacks for clothing and sleeping bags.
You need a larger pack. If you're hiking theres not much downside unless it tempts you to carry more stuff. Although on occasion I've had to use empty milk jugs as dunnage.

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Re: compression sack for sleeping bag, help with calculations please

Post by nerdymarketer » Fri Jan 05, 2018 1:06 am

Pajamas wrote:
Thu Jan 04, 2018 4:59 pm
nerdymarketer wrote:
Thu Jan 04, 2018 2:50 am
Please don't use a compression stuff sack, it can permanently reduce the loftiness of the bag, thereby reducing it's warmth.

More details: https://backpackinglight.com/forums/topic/57909/
That is usually considered to be a problem for down fill more so than synthetics like in the bag being discussed. Synthetic fill is less compressible than down but is not damaged as much by it.
I have always heard/experienced the opposite. That synthetic is damaged almost immediately, but down is only damaged by compression longer than 12-24 hours. See the thread I linked--looked like most others were saying the same thing.

Would love to see an actual study on this rather than just conjecture.

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Re: compression sack for sleeping bag, help with calculations please

Post by DSInvestor » Fri Jan 05, 2018 1:10 am

REI's page for current version of Cat's Meow comes with 23L (10X18 inch) stuff sack:
https://www.rei.com/product/103296/the- ... bag-womens

If you struggle to get your bag into your existing stuff sack, I'd suggest getting a compression sack that is larger (i.e. 30L). This will make it easier to put the sleeping bag inside before you squeeze it down. If it's really easy to get your sleeping bag into your stuff sack, maybe 20L compression sack would work.

Sea to Summit eVent compression dry sacks:
https://www.rei.com/product/730882/sea- ... n-dry-sack

If you live near an REI store, bring your sleeping bag in and try out different compression sack sizes. While you're in the store, take a look at the REI Joule 30 and 21 sleeping bags which are lighter and more compressible than the Cat's Meow. Joule 30 weighs under 2lbs and compresses down to 4.5-5.4L depending on size. Joule 21 with a lower temperature rating will weigh a little more and be a little larger than Joule 30 but still significantly lighter than the Cat's Meow. Something to consider if you'll be doing more backpacking in the future.
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sil2017
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Re: compression sack for sleeping bag, help with calculations please

Post by sil2017 » Fri Jan 05, 2018 9:18 am

I received the sea to summit event dry compression sacks in size small and medium from Omcgear online.( best prices) It was a struggle for me to stuff the cat's meow in size medium so I bought 2 more ( size L and M, just in case I need an extra one) I thought of buying the Ultra-Sil dry sack instead but CSR at Sea to Summit recommended the event as it has much more durable material than the ultra sil.

I stuffed my 4 top base layers, 3 bottom base layers, 2 hiking pants, wool hat, 4 pair of wool socks, 2 sock liners. There was plenty of space left for the M size.

I am thinking about using the size small for my down jacket or whatever else I need for my osprey daylight plus (20 liters) I need to carry.

I am waiting for the arrival of my Osprey Aura 65G early next week. I plan to take the top lid off, place 3 event compression sacks (S, M, L) and hopefully I can carry it on the airplane.

I called North Face and was told the Cat's meow would be sufficient for Lemosho Trek. I plan to wear my thermal and add my down jacket in case I need the added warmth. I also will be using my thermarest lite pad.

I have the Western Mountaineering Ultra light down sleeping bag but I don't want to risk the damage nor condensation. Thus, I am using the Cat's Meow instead.

After the private trek, I will join a no frill safari with a large group and I don't want to risk taking the down sleeping bag.

Livesoft- I don't like the cold!! :shock:

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Re: compression sack for sleeping bag, help with calculations please

Post by livesoft » Fri Jan 05, 2018 9:34 am

Sounds like you will have lots of fun and a great experience! You are heading for a top, too. Nice!
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Re: compression sack for sleeping bag, help with calculations please

Post by mak1277 » Fri Jan 05, 2018 9:38 am

White Coat Investor wrote:
Thu Jan 04, 2018 10:50 pm
nerdymarketer wrote:
Thu Jan 04, 2018 2:50 am
Please don't use a compression stuff sack, it can permanently reduce the loftiness of the bag, thereby reducing it's warmth.

More details: https://backpackinglight.com/forums/topic/57909/
You must take less stuff backpacking than I do if you have space to not use compression sacks for clothing and sleeping bags.
It's definitely doable to avoid compression sacks. I backpack a lot and I don't own a single one. Sleeping bag (actually down quilt) and clothes get packed loose in a trash compactor bag at the bottom of my backpack. I will say that I never take "extra" clothes. I typically take one "active" outfit for the day's hiking and one set of clothes for sleeping...no more.

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Re: compression sack for sleeping bag, help with calculations please

Post by barnaclebob » Fri Jan 05, 2018 9:39 am

Get a down bag, much lighter, warmer, and smaller. If you are going to kili you can afford it and you wont regret it. I had a 20 degree cats meow and I just barely might have survived the night in 20 degree temps even with a few layers on.

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Re: compression sack for sleeping bag, help with calculations please

Post by Pajamas » Fri Jan 05, 2018 10:25 am

nerdymarketer wrote:
Fri Jan 05, 2018 1:06 am

Would love to see an actual study on this rather than just conjecture.
Synthetic fill manufacturers do extensively test their products and most will provide spec sheets and testing information on request. Synthetic down fills have come a long way since the 1980s and 1990s. The proprietary fill in the Cat's Meow has changed over the years and is currently "Heatseeker Pro".

A high quality down fill is still the best choice over any synthetic in most circumstances. The primary reasons for choosing synthetic fill are lower cost and higher insulating ability when wet and faster drying time. With the newer lightweight and water-resistant fabrics like Pertex Quantum, moisture is not so much of an issue for a sleeping bag. I can pour water over my sleeping bag and it just rolls off. The problem is when water is combined with time and/or pressure, sleeping in a bag in a puddle of water, for instance. A down bag in a water-resistant stuff sack in a pack lined with a plastic bag should be fine even in wet conditions, as long as it is used on a relatively dry surface. A jacket that will be exposed to rain or perspiration is a different matter and synthetic may be a better choice even if cost is not a consideration.

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Re: compression sack for sleeping bag, help with calculations please

Post by livesoft » Fri Jan 05, 2018 10:28 am

One can buy bags and jackets with down treated to be hydrophobic, so that it is just like synthetic when it comes water and just like down when it comes to weight, loft, and compressibility.
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Re: compression sack for sleeping bag, help with calculations please

Post by Pajamas » Fri Jan 05, 2018 10:43 am

livesoft wrote:
Fri Jan 05, 2018 10:28 am
One can buy bags and jackets with down treated to be hydrophobic, so that it is just like synthetic when it comes water and just like down when it comes to weight, loft, and compressibility.
The treated down is inferior to untreated down in weight, loft, and compressibility. There are always trade-offs.

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Re: compression sack for sleeping bag, help with calculations please

Post by DSInvestor » Fri Jan 05, 2018 1:09 pm

sil2017 wrote:
Fri Jan 05, 2018 9:18 am

I am waiting for the arrival of my Osprey Aura 65G early next week. I plan to take the top lid off, place 3 event compression sacks (S, M, L) and hopefully I can carry it on the airplane.
I do not think that the Osprey Aura 65 in any size will be carry-on compatible. I believe carry on bags are limited to about 22 inches in length. The XS size is 29inches tall, S size is 31.5 inches, M size is 33 inches. Removal of the top cover will not reduce the height much. If you have to check the bag, consider putting the backpack into a duffel bag to protect the straps.
Link to Osprey page for Aura 65: https://www.osprey.com/us/en/product/au ... 8_568.html

I do not know if you're getting the new model or last year's model, but I do not think the height of the pack will change much between model years.

Link to page showing carry-on size charts for 150 airlines: https://travel-made-simple.com/carry-on-size-chart/

I hope you have had a chance to be measured for torso length before ordering your pack. Once you have positioned your hip belt properly on your hip, the Aura 65's shoulder straps can be adjusted up or down by about 3-4 inches.

Link to youtube video on the AURA 65 showing the shoulder harness adjustment: https://www.youtube.com/watch?v=6o6DpIYWbUk
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Re: compression sack for sleeping bag, help with calculations please

Post by halfnine » Fri Jan 05, 2018 5:31 pm

sil2017 wrote:
Fri Jan 05, 2018 9:18 am
....I am waiting for the arrival of my Osprey Aura 65G early next week. I plan to take the top lid off, place 3 event compression sacks (S, M, L) and hopefully I can carry it on the airplane......
I was a bit confused on the sleeping bag choice and the compression stuff sacks, but it seems the main reason for your choices is so that you can carry your crucial clothing and gear on the plane with you.

I'd reconsider the down sleeping bag. The porters are going to carry your sleeping bag and set up the tent for you. The sleeping bag isn't getting wet. As to durability, I took mine the duration of a gap year including Kili, multiple safaris and everything else bare bones travel could throw at it. It survived just fine. Actually, 20 years on another gap year and many more months of travel it is still going fine. At a minimum, and since you don't like the cold, put the two sleeping bags side by side and compare the loft and take the one with more.

I'd consider a synthethic jacket instead of a down. I suspect you are going to be wearing it on summit day. The synthetic jacket will handle a better range of conditions since Kili isn't always necessarily a cold and dry mountain.

For warmth I'd add a balaclava to your clothing list. And bring a 1L nalgene bottle. Fill it up with boiling water before you go to bed, wrap it up in some clothing so it doesn't scald you, and put it in your sleeping bag.

I'd be cautious about overstuffing a stuff sack. Criminally small stuff sacks are bad enough at home but in the cold and at elevation they can be an absolute pain. Consider you might also want to be able to do it with gloves on.

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Re: compression sack for sleeping bag, help with calculations please

Post by White Coat Investor » Sat Jan 06, 2018 12:17 am

Epsilon Delta wrote:
Fri Jan 05, 2018 12:39 am
White Coat Investor wrote:
Thu Jan 04, 2018 10:50 pm
nerdymarketer wrote:
Thu Jan 04, 2018 2:50 am
Please don't use a compression stuff sack, it can permanently reduce the loftiness of the bag, thereby reducing it's warmth.

More details: https://backpackinglight.com/forums/topic/57909/
You must take less stuff backpacking than I do if you have space to not use compression sacks for clothing and sleeping bags.
You need a larger pack. If you're hiking theres not much downside unless it tempts you to carry more stuff. Although on occasion I've had to use empty milk jugs as dunnage.
Ha ha. They don't make larger packs. I carry more stuff because I want more stuff when I get there. The more stuff is usually climbing gear, but sometimes it is sleeping bags, pads, and food for all these rug rats.
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Re: compression sack for sleeping bag, help with calculations please

Post by White Coat Investor » Sat Jan 06, 2018 12:17 am

livesoft wrote:
Fri Jan 05, 2018 10:28 am
One can buy bags and jackets with down treated to be hydrophobic, so that it is just like synthetic when it comes water and just like down when it comes to weight, loft, and compressibility.
Does it work? Does it work long-term? Why not do that to all down bags? Why does anyone buy synthetic bags?
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Re: compression sack for sleeping bag, help with calculations please

Post by livesoft » Fri Mar 30, 2018 12:37 am

Hi Silvana,

I'm curious how your trip went. Was your equipment more than adequate? Any updates?
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Re: compression sack for sleeping bag, help with calculations please

Post by Pajamas » Fri Mar 30, 2018 11:59 am

White Coat Investor wrote:
Sat Jan 06, 2018 12:17 am
Why does anyone buy synthetic bags?
They are cheaper and synthetic insulation is not affected by moisture in the same way that down is, although in my experience, it is rare that the insulation in a sleeping bag actually gets wet given the water-resistant shell and implementation of the reasonable and general precautions that are necessary to keep most all gear dry.

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Re: compression sack for sleeping bag, help with calculations please

Post by ImUrHuckleberry » Sat Mar 31, 2018 12:22 pm

White Coat Investor wrote:
Sat Jan 06, 2018 12:17 am
livesoft wrote:
Fri Jan 05, 2018 10:28 am
One can buy bags and jackets with down treated to be hydrophobic, so that it is just like synthetic when it comes water and just like down when it comes to weight, loft, and compressibility.
Does it work? Does it work long-term? Why not do that to all down bags? Why does anyone buy synthetic bags?
Have you ever hiked in the Northeast?

I use down but you have to be really careful to ensure you keep it dry in places like the White Mountains where you can be hiking for days on end in the rain and high humidity.

Some people prefer synthetic in wet climates because it gives them a little extra margin of error. That and synthetic is generally much cheaper which makes a difference for people on a budget and/or that don't get out hiking/climbing frequently.

Edit: Just saw the comments by livesoft about hydrophobic down which is new to me. So I guess the only reason for synthetic is likely the price difference.
Last edited by ImUrHuckleberry on Sat Mar 31, 2018 12:25 pm, edited 1 time in total.

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Epsilon Delta
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Re: compression sack for sleeping bag, help with calculations please

Post by Epsilon Delta » Mon Apr 02, 2018 1:40 pm

I'm allergic to feathers, which is sufficient reason to use a synthetic bag.

But I've also hiked in climates where no precautions will keep your gear dry, and there is no way to dry it once wet. If gear doesn't work when wet it doesn't work.

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Re: compression sack for sleeping bag, help with calculations please

Post by White Coat Investor » Wed Apr 04, 2018 9:16 am

Epsilon Delta wrote:
Mon Apr 02, 2018 1:40 pm
I'm allergic to feathers, which is sufficient reason to use a synthetic bag.

But I've also hiked in climates where no precautions will keep your gear dry, and there is no way to dry it once wet. If gear doesn't work when wet it doesn't work.
Fair enough.

I disagree that gear cannot be kept dry hiking. You might have to treat it like a canyoneer/river runner (i.e. dry bags and kegs), but you can keep a down bag dry even if it spends a good portion of the day underwater.
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Re: compression sack for sleeping bag, help with calculations please

Post by Epsilon Delta » Wed Apr 04, 2018 9:27 am

White Coat Investor wrote:
Wed Apr 04, 2018 9:16 am
Epsilon Delta wrote:
Mon Apr 02, 2018 1:40 pm
I'm allergic to feathers, which is sufficient reason to use a synthetic bag.

But I've also hiked in climates where no precautions will keep your gear dry, and there is no way to dry it once wet. If gear doesn't work when wet it doesn't work.
Fair enough.

I disagree that gear cannot be kept dry hiking. You might have to treat it like a canyoneer/river runner (i.e. dry bags and kegs), but you can keep a down bag dry even if it spends a good portion of the day underwater.
Try the Scottish highlands in December. It doesn't get wet in the pack, it gets wet once you take it out of the pack and expose it to 100% humidity, fog, sideways rain/sleet and your own body moisture. If you are very careful you can avoid the sideways rain, but not the other three.

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Re: compression sack for sleeping bag, help with calculations please

Post by barnaclebob » Wed Apr 04, 2018 9:32 am

You guys that hike in these terrible rainy conditions where its impossible to dry out a sleeping bag must be masochists. Surely these can't be regular trips right? Could I survive a week on the Olympic peninsula in December with a down bag? Probably but I'd still be wishing I wasn't there even with a synthetic sleeping bag.

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Re: compression sack for sleeping bag, help with calculations please

Post by White Coat Investor » Wed Apr 04, 2018 9:58 am

barnaclebob wrote:
Wed Apr 04, 2018 9:32 am
You guys that hike in these terrible rainy conditions where its impossible to dry out a sleeping bag must be masochists. Surely these can't be regular trips right? Could I survive a week on the Olympic peninsula in December with a down bag? Probably but I'd still be wishing I wasn't there even with a synthetic sleeping bag.
Agreed! Sounds miserable! Coastal Alaska can be like that too.
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Re: compression sack for sleeping bag, help with calculations please

Post by livesoft » Wed Apr 04, 2018 10:08 am

At least the rain can often (not always) keep the mosquitoes away.
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Re: compression sack for sleeping bag, help with calculations please

Post by Epsilon Delta » Wed Apr 04, 2018 10:59 am

White Coat Investor wrote:
Wed Apr 04, 2018 9:58 am
barnaclebob wrote:
Wed Apr 04, 2018 9:32 am
You guys that hike in these terrible rainy conditions where its impossible to dry out a sleeping bag must be masochists. Surely these can't be regular trips right? Could I survive a week on the Olympic peninsula in December with a down bag? Probably but I'd still be wishing I wasn't there even with a synthetic sleeping bag.
Agreed! Sounds miserable! Coastal Alaska can be like that too.
At least we don't have to carry our own air and risk pulmonary oedema.

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Re: compression sack for sleeping bag, help with calculations please

Post by RustyShackleford » Wed Apr 04, 2018 11:26 am

nerdymarketer wrote:
Thu Jan 04, 2018 2:50 am
Please don't use a compression stuff sack, it can permanently reduce the loftiness of the bag, thereby reducing it's warmth.
I agree. If you need a compression sack, you need to carry less stuff or get a bigger pack.

Also, they tend to be kinda heavy, with all the straps and stuff.

IMHO, these are the way to go. Weigh around and ounce or so and are waterproof:

https://mountainlaureldesigns.com/produ ... -dry-bags/

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