Converting a 30 Degree Bag into a 0 Degree Bag

How doable, time-consuming, and worthwhile would it be to convert a 30 degree bag into a 0 degree bag? Am I just talking out of my ass here, or is this something that can be done? I imagine you'd buy the down you wanted, re-stuff the bag (this would be the time-consuming part), and sew it back up. If anyone has experience with this kind of thing or any type of DIY experience please chime in. I'm at the point where I need a 0 degree bag, just don't have the 0 degree cash.

Cheers

Better off just doubling up. Get a down quilt and drape it over the 30 degree bag.

Is there a reason you want to make it a permanent conversion as opposed to a liner? You could get the warmest thermolite liner they make, wear your jacket in your bag, put a nalgene full of hot water in the bottom of the bag, and do some jumping jacks to get your heart rate up right before you hop in. All are pretty effective at warming you up. If you wake up cold in the middle of the night do a bunch of sit ups to get that heart rate up again.

Not worth the trouble.

First, without increasing baffle depth (i.e. effective loft) you are just compressing the insulation more which does not insulate better. Over compressed insulation results in worse R value.

I don't know your application, but if you don't have to carry on your back, just throw another bag or as Kai said quilt over you.

And, use a mat that also has good R value. Warmest single mat I have used is exped downmat 9. The inflated mat with down is excellent. This doesn;t help your finances though.

And eat some extra fat a couple hours before bed. A few spoonfuls of peanut butter helps me stay warm through the night.

Id get a down blanket like the jacks r better. I have one-slept in it all summer here in alaska during the summer down to 15 degrees. Layer it over your current bag and you'll be set for a while and then you have a sweet bag for the summer.

For a very low price, a vapor barrier liner gains you up to a 20F colder rating. At the same time, it neglects/eliminates the advantages of wearing extra clothing while you sleep. i.e. you typically don't do both at the same time. But, it sounds like you need a 30 degree difference. That is huge.
If your bag is sized large, extra clothing can make a big difference, especially if you own, and have room for, wearing a down jacket, etc.
I do a lot of winter camping, and figure that you need at least a bag rated down to 20F before you start talking modifications, or how far you can push its limits. 20 degree bags are pretty cheap if you look for sales.

Thanks for the replies. Now that you mentioned baffle depth it makes sense. I have thought about liners but I never found that they worked well. I'll try out some of y'all's suggestions. Cheers

Like what's been said, over stuffing the bag would make it colder, as adding too much would compress the down and cause it to lose its loft.

Vapor barriers make a huge difference. Easily 30 degrees warmer. The shitty part is getting drenched in your sweat at night + inability to wear clothes inside a VB liner. Something I've used with great success is vapor barrier clothes with a brushed nylon surface. Keeps the sweat away from your skin and you can pile on warm clothes over the VB with no ill effect.

warmlite.com/vapor-barrier-…

marty funkhouser wrote: The shitty part is getting drenched in your sweat at night + inability to wear clothes inside a VB liner.

put those down poofays on top of the vapour barrier under the sleeping bag

that way you can use all your insulation at night

;)

Anybody tried one of these $50 SOL breathable reflective bivvy sacks?
rei.com/product/832336/sol-…

Seem to get pretty good reviews and users are claiming 15 degrees or so added comfort range when used outside a sleeping bag. Combined with an extra fleece bag liner, it might get you closer to your goals?

Rframe wrote:Anybody tried one of these $50 SOL breathable reflective bivvy sacks? rei.com/product/832336/sol-… Seem to get pretty good reviews and users are claiming 15 degrees or so added comfort range when used outside a sleeping bag. Combined with an extra fleece bag liner, it might get you closer to your goals?

I've used the cheaper ones, and have been drenched inside of them. Not sure about the $50 one.

If your willing to sew then google.com/webhp?sourceid=c… have at it. Making your own bag and bivy would be proud.

Personally have only done small sewing projects, and that's enough, I opted to buy and nice bag and bivy.

It looks like there's a TON of info on DIY bags. My only problem is my lack of experience in sewing so I'd have to practice a bit before attempting the real thing.. It's definitely got me thinking. I may try to construct a bivy sack and eventually work my way up to something as complicated as baffles, hoods, feet compartments, etc. I'm always interested in the replies guys, keep em coming. Cheers

Vapor barrier and bivy sack. Neither increase loft, but both increase warmth through preventing evaporatative and convective heat loss. They will also help keep the bag drier, which over a few days or weeks will mean a warmer bag.

I've used my 20F bag down to 0F with a vapor barrier, light fleece liner and bivy sack. Total weight <5lbs, which is heavier than a proper 0F bag, even a cheap one, but some people choose to bring a vapor barrier or bivy with them anyway (to keep the bag dry) so it's not really all that heavy.

I appreciate the offer, I'm just not in the market financially for a big purchase right now. Bills, bills, bills, ya know? I'll definitely take a look at getting a cheap fleece liner. Who knows what I'll find! Cheers

Cultivating Mass wrote:I might sell it o you cheaper than you think. It's had no use in 3 years and I got it on clearance. Make me an offer.

That's awesome