When I was on an imaging marathon and came across a slightly bad disk I usually try to blow it due to a hair or crumb stuck in there for some reason and repeat the imaging process to see if it actually reads the bad sector (or if it moved to another sector to ruin that's okay too)

blowing disks may introduce moisture to the disc so do this at your own risk

also always ignore those aholes that just say 'throw it away 😀 obsolete media is dead 😀 😀 😀'

I know your asking about 3.5 disks but I have successfully imaged 5.25 disks that had mold / dirt by slitting open the covers and washing them under water and mild soap then letting them air dry and putting them in a clean cover. We did have to clean the floppy drive after every 3/4 disks. These disks were Apple ][ floppies. I am confidant you could do the same with a 3.5 floppy if you are careful and don't mind losing the original.

leileilol wrote:

blowing disks may introduce moisture to the disc so do this at your own risk

I wonder if that's how these disks ended up like this. I did used to use that method 17 years ago to "clean" them, when I was trying to unzip the last floppy of a set of 10 and there were read errors at 99%.

appleiiguy wrote:

I know your asking about 3.5 disks but I have successfully imaged 5.25 disks that had mold / dirt by slitting open the covers and washing them under water and mild soap then letting them air dry and putting them in a clean cover.

Yeah, that's the process I'm already familiar with. However there are no new 3.5" covers/cases, so I think that wouldn't work.

appleiiguy wrote:

I am confidant you could do the same with a 3.5 floppy if you are careful and don't mind losing the original.

The problem here is that I wanted to recover the original so I can continue using it. Recovering the data would also be a good thing to have of course.

Well, in the name of science I decided to try a few things, and none of them worked so far (and resulted in destroyed disks):

- Method 1: Put them under the water tap and spin the disk manually to spread the water inside. Initially the disk seemed to be getting cleaner, but then the cloth inside it started to absorb all the water which created a lot of friction resulting in the inability to spin the disk. However I tried to force it a little bit and that only caused the cloth to come lose in some points. Basically this method only works if you get the disk out of the plastic casing. Result: disk is destroyed.

- Method 2: Similar to method 1, but with one or two drops of isopropyl alcohol. Here the disk doesn't adhere to the cloth anymore, but apparently it also takes a lot of time for the alcohol to dry. Since I was impatient and was tired of manually spinning the disk I tried putting it inside the drive so it would spin faster. This sort of worked, but the disk continued to be unreadable, and there was a scraping mark afterwards, so clearly the drive didn't like to encounter a thin layer of alcohol on the disk's surface. After further inspection the mold is still there, so the disk is now unreadable and the mold is still there. I'm not sure if the disk was further damaged by this method, or if it was already like this when I began the process. Next time I'll pay more attention to these details. Result: disk is probably destroyed.

Method 3: use kerosene in a bowl, put the disk in, set it on fire! Mold is gone, disk destroyed 😉

(couldn't resist, ignore me)

Afaik if a reasonable use of isopropyl alcohol damages the disk surface, the floppy was already unrecoverable/decomposed/lost to begin with.

See my past bad experience here!

I sometimes find smaller or bigger stains of white mold on the surface (not on the whole disk) that I remove with gentle use of a cotton swab imbued of ... water. If it doesn't dry with just soft movements, you can dry the part with a dry cotton swab.

Throw it away. It is obsolete media....😉

I tossed out a half a banana box of the things.

Naphtha maybe? Not sure if it would eat the media. Generally safe on plastics so might work ok.