Sticky Black Rubber

No its been an issue for years, some shavers cameras binoculars and sundry other things even portable radios do this. Its not a cheap Chinese crap problem its the actual material used that leaches the very substance that makes it feel like rubber. In fact one famous cassette mechanism made by Wollensac was notorious for the pressure roller suddenly turning to a gloopy buddle on the bottom of the deck due to this issue. Its just not stable enough over time. It can get worse if its subjected to cold and hot temperatures as well as mechanical deformation.

I'm sure there is a chemist out there who can tell us the technical reason. Brian

Not really, once it goes I find you need to remove it, or bin the item ... I now avoid items with this "luxury" coating.

Ok Brian thanks, I have the parts soaking in a weak vinegar solution at the moment, that should kill the stickiness if it is silicone based. Youtube items suggest acetone, but that is too harsh and could dissolve the item. Isopropyl alcohol might be a good choice.

It?s a bastard to remove. I have some Kef ?egg? loudspeakers that went all sticky. Tried every solvent we could lay our hands on but never found anything that was particularly effective. Eventually I disassembled them and took them to an alloy wheel refurbisher who shot blasted and recoated them.

Sorry, not terribly helpful for you.

Tim

IPA and a rag, something wooden like a lolly stick for the stubborn bits

Could be worse - I've got a couple of hand tools with that sort of coating, and it's covered in what looks like mould. Wiped with a bleach solution seems to have fixed it for now.

Leaches from where?

The stupid "soft touch" coating degrades over time normally fairly slowly as in years but I note that the coating on the trimmer that SWMBO'd used to cut my hair a month or so back has now gone sticky. It was fine before and several years old. She uses hand cream, I don't...

As for cleaning up, the last object I had that suffered this problem responded well to meths, blue paper roll and elbow grease. The trimmer is in line for the same.

Surprisingly the answer is yes. I tried it (as recommended here some years ago) and it worked for me on several partly decomposed black vinyl rubbery things including a Psion 3c, a torch and a vacuum cleaner.

It does require a fair amount of patient and elbow grease to do a good job and there is a chance that other hard plastic bits will get damaged.

Don't wear any clothes you are fond of the black gunk sticks to everything it touches!

It slowly depolymerises at the surface becoming sticky tacky horrible probably the from effects of ozone and NOx in the air.

The surprise solvent for the tacky black stuff which will allow you to polish off the surface without destroying the sound material underneath is brake fluid (wear gloves when using it as a cleaning fluid!).

I found some when clearing out my dad's garage and having several such scrap tacky objects lying around couldn't resist trying it out. To my immense surprise it worked!

I had a car windscreen sucker mount for a mobile phone that went this way.

Nothing really worked.

Scrape and scrub with detergent. Mount less sucker was re-purposed into a tripod mount for smart-phone videoing

As others have said some solvents will remove it. But that will only be temporary - it will return.

If you don't mind how it looks, the quickest,and cheapest remedy is talcum powder (I guess flour would do as well). Covering it with the fine powder removes the stickiness immediately without having to worry about solvents. It is also simple to reapply when the stickiness reappears.

Remove the entire coating down to base plastic.

I was going to say it is de-polymerisation, but Martin has just said that!

Yes, and lots of grease, of the elbow variety.

Nothing to do with being of Chinese manufacture. Or certainly not exclusive to them. Happens with many soft touch plastics.

Must remember that one!

Tim

Some hard plastics go sticky after a few years. I've got a dynamo battery torch that is really nasty.

It's odd, really. We're told just how bad plastics are for the environment since they have a very long life. But often their life isn't good enough for the original application. Lots of moulded plastic on the old car which has gone brittle.

Try Car Brake fluid