Switch out the sleeping bag insulation

One of my friends brought up the idea of literally cutting open his synthetic sleeping bag, taking out the insulation and replacing it with down insulation. He is usually a crazy thinker, but is this in anyway possible?

I've looked through some old threads on sleeping bags, but I did not find anything like this. Only threads about how to make a sleeping bag from scratch which is not what I'm talking about.

I took a down bag apart and made a quilt. Then I took a synthetic bag apart and made an underquilt. Not sure if it would be worth the effort to make a down bag from a former synthetic bag due to the different type baffling that would be used. Also the syth bag material, if re-used, would leave a lot of thread holes that would potentially be feather loosers down the road. In my thoughts it would be easier to just make a down bag. If you have the down - why waste it on old fabric when new fabric could be used and the sythetic bag could be used for another purpose.

My suggestion ( assuming you no longer want the synthetic bag)- take the synthetic bag apart carefully. Take note of how it is made. This can be a great learning experience. Then use the insulation and materials to remake a quilt for summer use, or hat, or a jacket.

hooty was that a messy afair when you converted the down bag?

You need to concider how sleeping bags are made. You can not just take out the insulation. It is sewn in in many places. You need to rip out seams, alot of seams. As previously mentions, you could re-use the materials, but you would be saving only 40-50 dolars and you would be degrading the materials. The zipper might be worth salvaging as they are 10 dollars.
Possible... kinda. Worth it... not realy.
Scott

I asked this a year ago and pretty much came to the same conclusion as TB above <img src="/forums/images/graemlins/tongue.gif" alt="" />

I thought as much. No way it would be as easy as switching out the insulation. Boy we sure can wish though.

The greatest problem I see with this is not the construction but the fabric. Synthetic bags and down bags are made of different fabrics: down bags need to be made of down proof fabric to stop the tiny feathers escaping. They creep through that in the end too, but you cannot put down into a non-downproof outer. Not only will it escape into the outside world, but it will migrate through the lining and stab you, cover everything in sight in down, and get up your nose - literally!

how about switching it with Climashield???

Even then you run into issues. Most DIY'ers use offset quilting. Most manufactures use baffled construction. When I took my Slumberjack bag apart, I descovered that the fabric did not run head to toe but three strips ran side to side. What looked like a seam holding a baffle, was actually a seam holding a baffle and a structural seam holding two peices of nylon together. So basically what we make is much more simple than what the manufactures make. Not to mention they have sewing machines that can do things that your machine can't.
But, hey its your time and sanity...
Scott

I'm unfamiliar with the UK manufacturers, but on this side of the pond they mostly use the same fabrics, except maybe at the very low and very high ends, cost-wise. Primaloft does require downproof (or rather, Primaloft-proof) fabric, or it will "beard." Continuous-filament insulation may not, depending on the construction.

In any case, the synthetic-to-down conversion is impractical, as the other posters have said.