Finger prints on my gadgets


It’s something almost all of us have, a touch screen device. Almost all mobile phones now have a touch interface of some description that we daily poke at with our grubby fingers. Even if your fingers are particularly clean right now they are still producing sweat and oils which get all over the screens of our devices each and every time we glide our finger over them.

Most middle to high end phones (Samsung S series, iphone etc) have a factory applied oleophobic coating, a mixture of chemical compounds which repel oil, they decrease the amount of fingerprints visible on the screen. This coating doesn’t stop them altogether, but it reduces the amount and makes wiping them off far easier.

All well and good then? Yes, for a bit. This oleophobic coating is just a coating applied to the screen after manufacture, it doesn’t last forever, Gorilla Glass or Dragontrail it wears off dependant on the use your screen sees. My trusty rooted Samsung S2 came with this coating, I can now see that the center of the screen (which has taken a beating from my digit) attracts more fingerprints than the outer edges of the screen as the oleophobic coating has been worn off.

I’m not obsessed about having a perfectly clean screen, but I also don’t like the smeared look! I also don’t like screen protectors, why have super-tough glass covered by a bit of plastic……………. There is a Japanese company which is now making an oleophobic coating which can be applied to any glass touch screen. Made by Fusso it can last between 3-6 months, but it’s not cheap, at about $25 per kit. Another online ‘tip’ is to coat your screen with Rain-X, however Rain-X is hydrophobic, or H2O repellent, it’ll keep the rain off at least!

As ever I want it NOW, I want it better and I want it cheaper. This issue is not directly linked to my good old S2, but for my new Xperia Z1 Compact which comes with a crappy piece of plastic over my Dragontrail screen. Yes i’m aware that this ‘crappy piece of plastic’ is actually an anti-shatter film (ASF), but really Sony? (I hear the Z2 is finally free of an ASF on top of the screen at last). If I drop my phone from high enough it’s going to get bust, most likely the screen, with or without the ASF it’s a $200 repair. So now thats off and I have a nice clean Dragontrail screen which feels great, it’s getting covered in fingerprints, there’s no oleophobic coating…………

To find a solution without paying $25 we need to know what makes a good oleophobic coating. Well we need a/or a composition of compounds that are not soluble in Lipids, or fats. If the compound is not soluble in our chosen solvent (or liquid) it will naturally be phobic to it, or repel it. The cheapest is water (we all know oil and water don’t mix), fine for my Z1 to be drenched in water but not my S2! Fluorocarbons are the next (basically Fluorine and Carbon combined), great……….where do I get those then? Actually they are probably in your kitchen right now, it’s almost a household name, it might have helped you cook today, Teflon. Teflon is a Fluoropolymer, or a solid version of Fluorocarbon, that’s why your bacon doesn’t stick to the frying pan. As a long lasting polymer applying this involves some chemistry and high heat which is not very DIY, or phone friendly. An easier solution would be to buy Teflon as a wax or liquid thats easy to apply, well there are products used on skis and snowboards which contain Fluorocarbon, or liquid Teflon. These are $10-$15, but I think theres a cheaper way – PTFE tape. Polytetrafluoroethylene to be exact, this is used mostly in plumbing to wrap around threaded joints to stop leaks. So we have Fluorene bound as a polymer with ethylene (a hydrocarbon) to form a soft pliable tape, Teflon-tape! (Except ‘Teflon’ is owned by Dupont who don’t make tapes, hence why it’s called PTFE tape not Teflon-tape)

So the process:

Make sure your screen is really clean, having brought a roll of PTFE tape for about 50c, rip a length off and wrap it around your finger, now gently rub the tape over the screen always in the same direction, keep changing through 45 degrees. This will leave streaks and bits of PTFE tape on the screen which is what we want, it’s leaving an extremely thin layer of fluorocarbon behind. Now a light squirt of cleaner gently removing it then a buff-up using a microfibre cloth. Keep repeating to slowly build the layers up, an almost free oleophobic coating!

Fingerprints are now drastically reduced on my ‘naked’ Z1 Compact, those that do get on are easily cleaned by breathing on the screen and wiping it. Feel free to comment especially if you have a great finger smudge removing tip!

EDIT: In my ongoing search for cheap oleophobic coatings i’ve also discovered silicone based water proofing spray (such as Fabsil) to work rather well, it’s far quicker to apply than PTFE tape. Simply spray a small amount onto a cloth, wipe over the screen, leave for a bit then polish off using a microfibre cloth.

Image here