(Advanced tips) Cleaning floppy discs

[philpem]

I first spotted this trick on a Youtube video by ClassicRetroGamer -- https://www.youtube.com/watch?v=MPSqwaeMxTE. This is pretty good for dealing with floppies which have been stored in sub-optimal conditions (damp lofts, warehouses or garages for instance)

3.5in discs (and general hints)

The name of the game is to closely examine the surface of the floppy disc under a strong magnifying light at various angles, look for dirt on the surface, and gently clean it off. With 3.5in floppies this can be done by holding the shutter open, and turning the hub of the disc.
I use a "rocket blower" (often used for cleaning DSLR camera sensors or film) to get loose dirt off, then use a foam swab (https://www.amazon.co.uk/Pieces-Cleanin ... B07Z7YW961) and 70% isopropyl to remove anything which is more firmly attached.
As the head moves from the outside in, it's better to move the swab from the outside in -- which would push any dirt which isn't removed towards the hub and out of the way of the head.
Check each side of the disc, clean both sides, then rotate. Don't rotate the hub unless you're absolutely sure the area is clean of dirt and especially grit.

To make this easier, you can 3D print a disc holder frame and hub: http://www.makercentral.net/pages/cleaning-kit.php (thanks to Stephen Vegas on the Greaseweazle Facebook group for this: https://www.facebook.com/groups/greasew ... 446955616/ )

I had better success than CRG did, though not 100%. One disc (a work disc) went from having spots of bad sectors to reading 100%. Another seemed to have surface damage and cleaning made it worse. Moral of the story is to carefully examine the disc and make sure you're dealing with dirt and not surface damage.

If the disc is extremely dirty, consider moving the cookie into a donor disc housing. A metal spudger or "iSesamo" is great for this - run it along the bottom edge of the disc and snap the heat-stakes. If you're doing this, you can use the much faster Fairy-liquid trick below to clean the surface of the disc cookie.

Be extremely careful not to detach the metal hub from the cookie. If it seems to be coming loose, glue it back down with E6000 or similar adhesive. (Don't use Superglue as it outgasses and will contaminate the disc and possibly the drive heads too).
If the hub detaches, you have very little chance of getting the tracks correctly aligned with the hub again. (hooray for mechanical tolerances and slop!)


5.25in discs

For 5.25in discs, the best way to go is probably the trick Arcadian introduced me to. Obtain a clean 'donor' jacket and cut it open. Discard the disc 'cookie'. Make sure the foam liner is absolutely clean. Don't try to clean it -- if it's dirty, you should find another donor disc.

Open the disc you wish to recover, and remove the cookie. Try to keep track of which side of the cookie is "up", but don't worry if you lose track.
Wash it in lukewarm water with a drop of Fairy liquid. Gently rub at the dirt with your fingertips and it should come off. Keep your fingernails short and well clear of the disc surface!

Cleaning should ideally be done with distilled or deionised water. Tap water should be okay in soft-water areas, but avoid using it if you're in a hard-water area. Most car parts shops (and Wilko) stock bottles of deionised water - it's used for topping up car batteries. You can also buy many-litre tanks of the stuff on ebay for comparatively little money. You can also get replacement lids for the tanks which have taps built in - which makes the water far easier to draw off and reduces the risk of it becoming contaminated.


Like 3.5in discs, 5.25in discs have track zero on the outermost edge and the head moves inwards as the track numbers increase. Push dirt towards the centre if you can.

When you're finished, rinse the disc off and place it on a microfibre cloth. Pat it dry. Optionally spritz on a little isopropyl (70-99%), this will pick up any remaining water and help it evaporate faster or carry it off the disc -- further reducing the risk of leaving watermarks. (although the washing up liquid should help with this in the

Once you've got the disc clean and it's dried off, load it into the donor jacket. Image the disc straight through in a single run, as a double-sided 80-track disc.

If you get a disc full of read errors or the sector headers seem to be after the data, remove the disc and flip the cookie over.
If your imaging software supports it, you could also try reversing the timing data (sometimes done when imaging "flippy" disks in a double-sided drive).

[flaxcottage]

I must be a dinosaur! I use 50% IPA/H20 on a cotton wool bud on my 5.25" discs and clean the surface through the 'window' in the jacket, rotating the disc slightly and repeating. I line the index hole with the hole in the jacket and rotate the whole disc until the index hole reappears. This has worked every time except for two discs which were so damaged one could see through the disc.

[philpem]

Every old trick is new again!