Thread: Sleeping bag thermal liner

Hi, just wondering whether anyone uses a thermal liner, particularly one of the sea to summit thermal liners in there bag to boost the rating. I’ve always used a silk liner but wondering whether the thermal liners actually work and are breathable like the silk ones.
Am I best to just buy a higher rated bag and continue with the silk liner.
Cheers

I use a sea to summit reactor and its bloody great breathes certainly helps stay warmer and also protects the inside of your bag too. I picked mine up a lot cheaper than rrp off this site too. Money well spent imo

I've got 2 of them. The +8 model and the +14. So kind of a modular approach to having a liteweight sleeping bag. Depending what the overnight temp forecast is when I'm going.
Yes I think they add quite a bit of warmth to the bag. Yes they are breathable. The draw string works well to cinch it in a bit to stop cold air getting in. Dry out very quickly. I prefer the feel of them to the silk liner I used to use.

Awesome thanks, sounds like it’s worth a try.

yes, have used the +7-8 C Reactor with a light weight bag quite a lot. Works very well for 3 seaons. Recently added the +14 version as an option for cooler months

Get a 300 gsm polar fleece sheet from briscoes for $18

Sew it into the shape of your sleeping bag and use it as a liner

Make two if you want and use the second one as a bivvy bag


Makes for a clean sleeping bag and very warm sleeps

S2S Reactor is brilliant- and takes very little space. The basic fleecie lining will be a lot bulkier

Yip I use sea to summit reactor,definitely adds warmth and keeps bag clean.Packs down small

$15 warehouse jobbie...slightly biggerthan coffee cup in its stuff sack....main job of liner is to keep your dirt/odour/oil off your good down bag....2nd to trap air and boost warmth....

As someone who’s never used a sleeping bag liner of any variety, how much of a difference do things like a silk liner or others actually boost warmth rating? My bag is getting very old & on a hunt in July I got cold for the first time overnight on a hunt. Was in a hut too. Even with my merino thermals, puffer & beanie on I was still chilly. Stayed in the same hunt the previous July in worse conditions without getting cold at all, & there’d been no dry wood for a fire that time either. Will be buying a new winter bag, but just keen to give this one a wee boost if possible for rest of year cos it’s still got plenty of life in it.

chuck it in tumble dryer with tennis balls and clean running shoes for hour or so to beat it up and even out the down....a liner in bag makes about same difference as summer vs winter sheets on bed.... it traps air closer to body than bag alone....if you close to wagon..a single winter sheet sewn down one side and across bottom will really boost the warmth but is heavy n bulky compared to tiny wee liner.

@Micky Duck I’ll give the tennis balls and dryer trick a go cheers. I will say the bag is getting very old, so no doubt it has lost a bunch of down over the years. As we get closer to summer it should definitely be warm enough, but will most likely get a new winter bag regardless.

Originally Posted by kimber08

Hi, just wondering whether anyone uses a thermal liner, particularly one of the sea to summit thermal liners in there bag to boost the rating. I’ve always used a silk liner but wondering whether the thermal liners actually work and are breathable like the silk ones.
Am I best to just buy a higher rated bag and continue with the silk liner.
Cheers

This is the dilemma of the ages @kimber08. I have a solution to consider. I recently got a set of K3 Nato thermals from Sarvo for the purpose of winter sleep wear in a Halo bag. So I am sticking with the silk liner and have thermals to change into for bed. The thermals are a dry change for when I get back to camp. I wore them around the farm for five days all day and slept in them every night (after a shower) so 23 1/2 hours a day to see what happened. After five days no smell, warm all day, too warm at night and never go sweaty or wet. Then I washed them and compared the drying time to all sorts of other thermal stuff of similar thickness and they dried fastest.

That’s awesome, great dedication and information there! …but 30min showers??😜