Sleeping Bag Liners?!?!

I am getting ready for a solo winter 2 night hike and only have a 40 degree bag. I was thinking about making a fleece liner but wasnt sure of the best (warmest) way to got about making one. i am not stuck on using fleece, i just want the warmest cheapest way to make a good bag liner.

Please Help so I dont freeze!!!!

Two things,
1. Here is a plan for the cheapest version you could make. The wallmart idea was brilliant, I would have paid 3x as much for just the fleece. http://www.backpacking.net/makegear/liner-quilt/index.html

2. Rather then get extra geared up, couldn't you just sleep dressed? I did it in my 30f Big Agnes bag at 5f, I was toasty! I would just wear my next days clothes to bed, and since they are clean you have no worries. I also can't stress enough that you will be 100x warmer when your head, feet, hands, and wrists are warm. Those places are where you lose the most heat. (Those wrist bands are a must!!!!! I even wear them when hiking or climbing. I can go sleeveless and as long as I have the wristbands on, I'm warm. Maybe it's psychosomatic but I swear it works, not a little either. That night I spent dressed I got over heated in the bag and just took off the wristbands. It cooled me so muc I had to out them back on an hour later.)

Best of luck.
[color:"green"] GuruJ [/color]

What kind of winter hiking you will be doing? Winter hiking that gets below 20 degrees? And how much time do you have to complete this. What is the condition of you current bag? How much suffering are you capable of? I'll assume that it will get cold and you don't have a lot of time. Buy a budget bag. Case in point. I made a 15 degree bag for my wife and we headed out for a winter hike. I made it 4 inches too short. Her feet cramped up the foot box compressing the insulation at her feet and head. She froze and the trip ended the next morning. Winter hiking is serious stuff and a miserable night will make you regret not buying a good bag.
As far as you question. Making an over bag out of nylon and insulation (primaloft/what ever else is out there) would be the best option.
Possibly another option is to go thrift store shopping for a down blanket (or a couple of them). I've found two of them that I'm going to steal the down for a summer bag. Use the blanket over your sleeping bag (or sew it into your fleece bag with nylon cover), wear all your clothes and make youself a better bag during the summer with the blanket when you are done with it.
Of course all these options are not as good as one dedicated winter bag. They will all be bigger and heavier and possibly not as warm. For all this effort, 100-150 dollars seems cheap (and I am a seriously dedicated DIY'er).
Or I could be completely wrong....
Scott

It would help to know what kind of 40F bag this is.
-Barry

I am with TurkeyBacon on this one. Of course it all depends on what "winter" is for you. For me, winter is anything below 15* F which necessitates very different gear than just a 3-season with an extra blanket. I have a Big Agnes 0* down bag I use solely for the winter. Well worth the cost and weight. Of course if "winter" for you is a chilly night in florida, then you'll likely be fine.

A bit late I think, but here goes.
There is a low end mummy bag sold in Walmart, fill about one pound, quality seems adequate for summer use.
Occasionally you can find them as low as $30 at the end of summer camping season.
You could use it as a liner and add maybe 25 degrees to the bag you have.
I have two. I bought them largely as liners, but limited use in the summer seems to suggest they are of adequate quality when used alone in friendly conditions.