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Now I've got a pack of old floppies that are outgassing :0 I have no other explanation. This is an almost-full box of miscellaneous floppies in one of the ori

Now I've got a pack of old floppies that are outgassing :0 I have no other explanation. This is an almost-full box of miscellaneous floppies in one of the original cardboard trays of 30 from Office Depot. I've got kilos more floppies in different closets but these are good ones I selected a few years ago that all passed SCANDISK. Now this one little box is in an old ziploc bag in the office and it keeps self-inflating. At first I thought it was unusually low barometric pressure one day but I keep squeezing out the air rain or shine and it keeps on puffing back out by itself. Something I really didn't expect. If I did still own my own laboratory, I'd tell you what kind of gas it was by now though ;)

userbinator 2mo ago
Are you sure it's not just the bag attempting to return to its original shape? They are also not truly airtight, so there might be some sort of osmosis effect too. The possibility of mold growth may also be considered.
- fuzzfactor 2mo ago
  These do seem all within the range of possibilities. The bag is old and imperfect, and I don't think it is completely airtight either. Not as much from permeability of the polymer but phyical wear & tear too. I smelled the exhaust when I deflated it the last few times and it is very faint but industrial. Doesn't smell like mold but organisms could still be hidden somewhere breaking down plastic or additives. Which may or may not consume oxygen. Osmosis I have been considering too, if fairly high molecular weight breakdown products are gradually emerging into the gas phase, with the bag way more permeable to atmospheric gases, maybe the atmosphere is forcing its way in and builds slightly higher partial pressure than ambient as a molar dilutive effort. This is a good time to put the floppies in a brand new bag and see what happens, the experiments never end ;)
stavros 2mo ago
Hm, if there's anything of note in the floppies, maybe archive them? There are some USB devices that will read and store the actual magnetic flux values, for max fidelity.
- fuzzfactor 2mo ago
  These had no special data on them to begin with, or things other than mainstream file storage. No irreplaceable game floppies and probably nothing worth saving at all, but it was only about 10mb total on all the disks combined, might as well save it on a HDD when the web wastes more of my megabytes than that in five minutes now. So the files were just backed up the regular way before testing a couple dozen disks for future use, and bagging them to keep out the dust. I tried to pick clean ones but actually probably kept in a bit of vintage dust when you think about it :)

userbinator 2mo ago

Are you sure it's not just the bag attempting to return to its original shape? They are also not truly airtight, so there might be some sort of osmosis effect too. The possibility of mold growth may also be considered.

fuzzfactor 2mo ago
These do seem all within the range of possibilities. The bag is old and imperfect, and I don't think it is completely airtight either. Not as much from permeability of the polymer but phyical wear & tear too. I smelled the exhaust when I deflated it the last few times and it is very faint but industrial. Doesn't smell like mold but organisms could still be hidden somewhere breaking down plastic or additives. Which may or may not consume oxygen. Osmosis I have been considering too, if fairly high molecular weight breakdown products are gradually emerging into the gas phase, with the bag way more permeable to atmospheric gases, maybe the atmosphere is forcing its way in and builds slightly higher partial pressure than ambient as a molar dilutive effort. This is a good time to put the floppies in a brand new bag and see what happens, the experiments never end ;)

stavros 2mo ago

Hm, if there's anything of note in the floppies, maybe archive them? There are some USB devices that will read and store the actual magnetic flux values, for max fidelity.

fuzzfactor 2mo ago
These had no special data on them to begin with, or things other than mainstream file storage. No irreplaceable game floppies and probably nothing worth saving at all, but it was only about 10mb total on all the disks combined, might as well save it on a HDD when the web wastes more of my megabytes than that in five minutes now. So the files were just backed up the regular way before testing a couple dozen disks for future use, and bagging them to keep out the dust. I tried to pick clean ones but actually probably kept in a bit of vintage dust when you think about it :)