I acquired a new mattress bag. The things are very heavy mil, probably greater than my commercial 9'x9' tarp. And thats the 'rub' literally. Trashbags, tube tents, space blankets; these are all field expedient, lightwieght and compact items. We are trading greater performance for availability. Theres a point of becoming 'penny wise and pound foolish' when you might as well acquire a dedicated bivy sack. As to fusing, remember you will need some venting for perspiration. I did the following when I played with 55 gallon bags. The bottom bag came up from my feet and I TUCKED the open edge into my pants like an upside down tshirt. The upper bag, with the all important face opening ( this is a survival, not potential body bag.) went over like a loose anorak pullover. The open bottom provides venting. Again, all of these units are great for augmenting a shelter of natrive or carried material. But at some point a dedicated assembly makes more sense.

Thanks again for you responses. I have tube tents, bivy sacks, and even Ruth Ward's 80"x 52" back pocket clear bags. I was asking for another reason. I may have received the answer on another forum, when it was suggested that I use the battery operated "chip bag re-sealers "available in most grocery stores for under $5.00.
Regards,
Al

The Eurosealer. It's a tiny heat-sealer for plastic bags. It takes some practice, but you should be able to seal trash or even contractor bags together. A lot lighter than even clear packing tape (which would be my second choice).

Someone else mentioned Christmas tree disposal bags. There are also bicycle gift-wrap bags that are huge. Or buy some plastic sheeting and a Eurosealer and make your own bag.

I just heard today that Harbor Freight has 2mil plastic bags, in two packs, which come in three sizes: 40"x72", 45"x96", and 60"x108". I don't have a HF store nearby to check...

Hey OBG:
I purchased the two larger sizes today. Thanks for the heads up.
Al

My pleasure. How do they look? Worth the cost???

Yes, $2.99 & $3.99 for a package of two.

Cool. Wear then in good health...