Plastic cases that go sticky

[807]

I have a technoline BL700 battery charger. The manufacturers thought it would be a good idea to give the case a "rubber feel" finish. That's fine to start with, but over the years the coating begins to break down & gives the case a disgusting tacky, sticky feel.

After looking online I tried a few suggestions to remove the tackiness, but none of them worked. So far I've tried IPA, citrus label remover, washing up liquid, soapy water, soda crystal solution, anti-bacterial hand gel & facial scrub.

Has anyone successfully removed this coating? It's found on some remote controls too.

[themadhippy]

wd40?its surprisingly good at removing some sticky residues.

[tunk]

Don't know the English term, but I used some abrasive scrub cream
(intended for bathroom/kitchen use) plus a stiff brush on a radio back
cover. The cover was removed from the radio, and it was scrubbed
in a sink. Worked well (apart from some mild scratches).

[tszaboo]

I don't think there is a way. It's that rubbery material, often times when it's in contact with plastic, which is doing it. I think it might be the additives in the plastic, which is doing it not the plastic itself.

[807]

I have WD40 here, but I wasn't sure if it would damage the plastic. I will use it as a last resort.

Didn't think of the bathroom cleaner. In the UK we have a product called Cif. I have some here. It's the lemon flavour with micro particles. I'll give it a go.

[807]

I don't think there is a way. It's that rubbery material, often times when it's in contact with plastic, which is doing it. I think it might be the additives in the plastic, which is doing it not the plastic itself.

After attacking it with all the products I listed, it has reduced the stickyness, but is still a bit tacky, so I think it can, eventually (hopefully) be removed entirely. I don't know why they need to use it at all on a battery charger. 

[jpanhalt]

I use WD40 very rarely for anything.  It will also leave a residue.

I have an older Nikon D70s camera that I got used for a specific purpose.  Its rubbery surfaces were sticky.  I don't remember exactly what I used, but it has stayed non-sticky for well over a year. I probably started with VM&P Naphtha, denatured alcohol (which is mostly methanol in the US), ethanol (absolute), and finally diluted floor stripper (1 part to 2 parts water).  Since WD-40 didn't work, I suggest jumping to the acrylic floor stripper diluted in water.  Rinsing with water will speed the evaporation and help get rid of the smell.   If you have ethanol, I would probably try that as an intermediate step.

[eutectique]

Fine coffee grinds might be helpful as an abrasive.

[magic]

I have done it successfully to a Razer "gaming" mouse.

IPA and lots of friction did the trick. I don't remember if I used some cloth or just paper tissues.

edit
Oftentimes the underlying plastic is ABS, so avoid acetone if that's the case. I would also be weary of any "acrylic stripper".
If in doubt, test on some not visible surface first.

[Ground_Loop]

I just (last week) had the same problem with my 3D mouse. Acetone stripped it right off. Fortunately the plastic underneath was not affected.

But my first attempt was with both IPA and WD40 which are typically my go-to’s for this kind of thing.  Neither worked very well.

[tooki]

I don't think there is a way. It's that rubbery material, often times when it's in contact with plastic, which is doing it. I think it might be the additives in the plastic, which is doing it not the plastic itself.

No, it’s just the synthetic elastomers decomposing with time.

At work, I just threw away a half sheet of old (really old, like decades) 3M Bumpon rubber feet that had degraded from clear rubbery plastic into sticky goop, a clear jelly that felt like Vaseline. These had never been attached to anything, so it wasn’t migration from plastic, because it wasn’t in contact with it.

Besides, plasticizer migration works the opposite of how you think: it migrates from soft plastics to hard ones and softens the hard ones. Plasticizer migration would result in the plastic going soft, not in the rubber going gooey.

[Gyro]

Meths (Methylated spirits - UK name), works as well as IPA to remove the coating completely with plenty of kitchen towel and rubbing. It's cheaper here than IPA and safe with most plastics, including ABS.

[jpanhalt]

Denatured alcohol is regulated.  There are many acceptable recipes.  As I said earlier, in the US, it can and frequently is mostly methanol


That's for "Klean-Strip QSL26 Denatured Alcohol"  Stuff sold for "fuel" can have even less ethanol.

In Britain, it might be different, particularly if sold as denatured ethanol rather than denatured alcohol.  Same rule probably holds in the US, but you won't find "denatured ethanol" at Home Depot.

Of course, denatured ethanol is also available on Amazon (I think), but the price is outrageous considering E85 is about $3/gallon.  I have tried E85 as a very cheap alternative.  It's not as good as absolute ethanol, but it's a decent solvent.  Unfortunately, it has a strong odor and fuel additives.

[Gyro]

I just had a quick look at a bottle of DIY store stuff that I have in the garage. The caution label says "contains Ethanol UN1170" but no mention of Methanol or complete ingredients list. Yes, purple in colour with distinctive smell. Sold for spirit lamps / stoves, hard surface, and glass cleaning, de-greasing etc. 

[jpanhalt]

Do you have the equivalent of the US SDS or MSDS (safety datasheet or material safety datasheet).  Virtually every "chemical" sold in the US must have one, including the white-out used in the days of the Selectric typewriters.  Are  IBM Selectric ball typewriters still used in Britain?   

Just search on its name & product number from a British site.

[Gyro]

I was just about to edit my post above. Yes, I found the datasheet for the cheap stuff on the DIY store site, attached. It's mostly Ethanol, <10% IPA, <10% MEK plus the colour and nasty smell/taste.

P.S. No more IBM Selectrics, more's the pity, they were fun to watch!

[Zero999]

Corrosive chemicals, UV radiation and even some bacteria can breakdown long chain polymers into smaller molecules, similar to the tars and waxes used to make them in the first place, hence the sticky mess. There's not much which can be done to stop this, other than keep it clean, although don't use strong chemicals to clean it, just soapy water, and  keep away from UV light.

Once this has happened, it's very difficult to clean off, since the sticky mess is strongly chemically bonded to the substrate. Some strong solvents such as acetone and even citrus oils can make it worse, since they will dissolve some polymers and can leech into plastic underneath, causing it to become tacky. If cleaning with alcohol (most should be fairly plastic safe) and detergent doesn't work, then you could try covering it with a lacquer, to encapsulate it. I don't think there's anything else which can be done.

[rdl]

Rubbery ("soft feel") coatings are a real problem because of their tendency to go sticky. I believe that the manufacturers don't really know why it happens yet they keep using it for some reason.

[jpanhalt]

Rubbery ("soft feel") coatings are a real problem because of their tendency to go sticky. I believe that the manufacturers don't really know why it happens yet they keep using it for some reason.

It's out of ignorance.  Customer ignorance.  Manufacturers do it on purpose.

[Halcyon]

I've used citrus-based cleaner with ethanol (sometimes sold as air freshener sprays). It works remarkably well on anything sticky. But be careful around areas that have printed text, labels etc... as it will erase those too.

[AndyBeez]

Possibly my top technical peeve!!! Perfectly servicable and valuable devices end up as scrap as the soft touch seems to 'melt' over time.

I have zero idea what the feck this stuff is, but the feel is very similar to the epoxy component in two part epoxy glue. It appears to be a clear coating applied over the plastic, but not bonded to the plastic.

The break down seems to be time related. Even in cold dark store, the soft touch coating turns into a sticky mess. Proof, the case of a temperature sensor gauge inside a fridge went to glue too.

The only effective method is to scrape off the cunk/funk, cut back to bare plastic with 800 grit paper and respray. Nothing chemical touches it. Acetone, IPA, bleach, mineral/white spirit, absolutely nothing. If you guys have a secret sauce, then please share.

(Photos to follow)

[amyk]

It's probably a polyurethane foam, one of the least stable plastics in common use.

[tooki]

I was just about to edit my post above. Yes, I found the datasheet for the cheap stuff on the DIY store site, attached. It's mostly Ethanol, <10% IPA, <10% MEK plus the colour and nasty smell/taste.

P.S. No more IBM Selectrics, more's the pity, they were fun to watch!

#LFMF and NEVER use denatured alcohol with Bitrex (denatonium) for cleaning! The damned Bitrex not only gets on your hands, but also on whatever you cleaned, recontaminating your hands every time you touch the thing. The result is... you realizing how constantly we touch our fingers to our faces without thinking about it.

[Nominal Animal]

Besides, plasticizer migration works the opposite of how you think: it migrates from soft plastics to hard ones and softens the hard ones. Plasticizer migration would result in the plastic going soft, not in the rubber going gooey.

Yup.  The worst offenders (as in way too much plasticizer) in my experience are fake "silicone" leads, which are really just overly-plasticized PVA PVC.
The result is that if you keep them in a plastic box, the lead can literally meld into the box, due to the plasticizers.

I often want softer multi-strand wires, and don't usually need the high temperature capability of silicone leads, so I wouldn't mind them being PVA PVC or some other non-silicone plastic, but the migrating plasticizer makes them annoying to store; they need to be stored away from anything plastic, including cutting mats and such.


The issues with plastic additives have existed for as long as plastics have been industrially manufactured.

Back in the previous century, when reversal/slide films were still widely used (called "dia" or "diafilm" here), sometimes the pocket sheaths used to store them in books had additives that caused film destruction in a few years to a couple of decades.

For soft overmoldings, I do believe butyl rubbers are the worst offenders, as they become sticky (especially so from human skin oils) in a few years.  Some varieties become stinky (vomit smell), as they slowly decay, one of the byproducts being butyric acid.

AvE has mentioned these butyl rubber overmoldings in his BOLTR videos on Youtube, including how oils speed up the decay of the overmolding; so that for industrial tools and tools used with oily hands (think mechanical repairs), they really don't last long.  My own worst experience has been with bicycle handles, which became tacky, more tacky than 3M post-it notes, in a few years, with that recognizable butyric acid vomit smell.  Eww.  Oh, and hand cart wheels, which were some black plastic with plasticizers, that stained a plastic/vinyl floor mat with yellow blotches when they sat there for a couple of months.  Dammit; should have waxed the mat better.

[RoGeorge]

For sticky rubber in hand tools, a second cover might be the way in case nothing cleans good enough.

Seen that done many ways, either by wrapping the handle with textile thread, or by covering the handle in huge diameter thermal shrinking tube, or even by covering with PET bottles heat-shrunk over the sticky handle.  Water and soda PET plastic bottles will shrink a lot when heated, and will shrink in diameter only.  When heated too much, the plastic will turn from transparent to milky white.

[Zero999]

I've used citrus-based cleaner with ethanol (sometimes sold as air freshener sprays). It works remarkably well on anything sticky. But be careful around areas that have printed text, labels etc... as it will erase those too.

Be  careful with some plastics. Citrus oil contains limonene which can dissolve some plastics. Most notably polystyrene but also ABS, which contains styrene and is commonly used in consumer goods.

There's even interest in using it for recycling polystyrene.
https://www.chemicalonline.com/doc/new-recycling-process-uses-limonene-to-dissol-0001

[807]

Thanks for all the suggestions, and some interesting info. 

I did try the Cif bathroom/kitchen cleaner, as I had some here. It helped to greatly reduce the tackiness. It is almost "normal" to the touch now, but not quite. There's just a slight bit of tackiness still. Just enough to be annoyingly noticable. I might give it one last go with the Cif, perhaps with the rough side of a washing up sponge this time. I would rather keep the labels intact, but if they get rubbed off then it's not too much of a hardship. I know what the buttons do.

On a similar note, it was mentioned in a previous post about rubber feet. I have a few Racal Dana 1998 frequency counters. A couple of them have metal standoffs at the back to protect the connectors. The standoffs have (or had) black rubber bumpers on them. When I was rearranging my test gear a few months ago, I took the counter off the shelf & stood it up on the floor. When I went to pick it up, it had stuck to the carpet! All 4 bumpers had turned into a gooey mess, like thick tar. Some of it had even run down the back of the counter.

[Gyro]

A dusting of Talc can be used to reduce the residual stickiness, but is a temporary measure as it will eventually soak up the plasticiser and add to the mess.

[tooki]

Besides, plasticizer migration works the opposite of how you think: it migrates from soft plastics to hard ones and softens the hard ones. Plasticizer migration would result in the plastic going soft, not in the rubber going gooey.

Yup.  The worst offenders (as in way too much plasticizer) in my experience are fake "silicone" leads, which are really just overly-plasticized PVA.
The result is that if you keep them in a plastic box, the lead can literally meld into the box, due to the plasticizers.

I assume you mean PVC? (PVA is the water-soluble polymer in white school glue and wood glue.)

I often want softer multi-strand wires, and don't usually need the high temperature capability of silicone leads, so I wouldn't mind them being PVA or some other non-silicone plastic, but the migrating plasticizer makes them annoying to store; they need to be stored away from anything plastic, including cutting mats and such.

FWIW, the softest PVC wires I've found that you can buy today* are the LifY from Kabeltronik. Many manufacturers make LifY, but most use the coarsest stranding allowed under the LiFY wire code. Kabeltronik uses much finer stranding.
For example, for 0.25mm²:
Standard flex LiYv for reference: 14 x 0.15mm
Helukabel LifY: 65 x 0.07mm
Kabeltronik LifY: 128 x 0.05mm

For larger cross-sections (0.75mm² and up) Lapp also resells really nice, super soft LifY.

Wire stranding alone doesn't tell the whole picture, but the Kabeltronik and Lapp are really, really soft.

I have a feeling that newer wires and cables are stiffer in general. To some extent that may be to make them environmentally friendlier, but I think a lot of it is just companies being cheap.

For example: at work, I found three reels of RG-174 cable. Two from Huber+Suhner (Swiss made, currently around $400/100m) and one from Tasker (made in Italy, around $100/100m). Despite both being the same spec, the H+S one is nice and soft, with smooth, flexible PVC insulation, while the Tasker one is stiff, with rough, matte, inflexible PVC insulation. The Tasker's insulation is admittedly easier to strip, but for test leads and the like, I have to use the H+S. I'm not sure why the flexible PVC would be more expensive, but it must be...


*At work I have a few old spools of Swiss-made Soflex PVC wire that is super-flexible. It also uses the 128 x 0.05mm construction. But the company that made it was sold multiple times over the years and as best I can tell, hasn't been made for many years, even before the current owner, Nexans, closed the Swiss wire plant. Nexans doesn't appear to super-flex wires at all, they seem more focused on electrical installation and transmission.

[AndyBeez]

... All 4 bumpers had turned into a gooey mess, like thick tar. Some of it had even run down the back of the counter.

I feel your pain! It seems that this type of 'rubber' turns into a crude oil slick, just because it can
This is also a self-destruction failure mode for drive belts inside 1980s cassette recorders.

A dusting of Talc can be used to reduce the residual stickiness, but is a temporary measure as it will eventually soak up the plasticiser and add to the mess.

Talc is very good for capturing the gunge before it's scrapped off using a dead bank card. I tried sawdust, but this just makes a mess on the bench

Despite the soft-feel coat being prevalent on many electronic devices made in China over the last 25 years, there is little information around as to what it is. One source suggested the material is a type of organosilane acrylate which, after application to a hard plastic surface, is 'baked on' using strong ultra violet light. This is when the soft touch surface texture forms. So it might be interesting to see what happens if a sticky case is exposed to strong UV light - is the degradation re-reversible? Interestingly, the soft surface is meant to be inert to solvents, detergents and alcohol. Which is why it is recommended for use in sanitary sensisitve consumer products like children's toys, phone cases, wearable tech and even, haptic toys for adults

Below, this is a pair of magnetic cupboard lights that are suffering severe degradation. In fact, they are so sticky, they can stick to the side of the fridge without using the magnets! I will clean them up over the next few weeks and hopefully report back. At time of writing, I have the sticky shells inside a bag of talc, which should help to soak up the worst of the crap. On the photo, see how the colour from the black plastic button has migrated into the sticky surface. Some weird chemistry going on.

[Gyro]

I think I mentioned it once before in another sticky goo thread, but I have a Logitech Harmony remote that suffered rubber breakdown on the rear surface. I completely removed the coating with meths to reveal... another, solvent resistant, Logitech logo. Now that's thinking ahead!

[Halcyon]

I think I mentioned it once before in another sticky goo thread, but I have a Logitech Harmony remote that suffered rubber breakdown on the rear surface. I completely removed the coating with meths to reveal... another, solvent resistant, Logitech logo. Now that's thinking ahead!

It's almost as if they knew/expected their product to degrade in this way.

It reminds me of a pair of running shorts I bought. The laundry tag literally says "Designed to fade".

[Nominal Animal]

I assume you mean PVC? (PVA is the water-soluble polymer in white school glue and wood glue.)

Right.  I'll be in that corner there stuffing crayons in my nose and eating wood glue.   

[Circlotron]

So it might be interesting to see what happens if a sticky case is exposed to strong UV light - is the degradation re-reversible?

I've got a USB stick with this very problem. I've put it in the EPROM eraser for 1 hour and we'll see what happens.

[5U4GB]

I just had a quick look at a bottle of DIY store stuff that I have in the garage. The caution label says "contains Ethanol UN1170" but no mention of Methanol or complete ingredients list. Yes, purple in colour with distinctive smell. Sold for spirit lamps / stoves, hard surface, and glass cleaning, de-greasing etc.

It depends on the country, "methylated spirits" here is almost pure ethanol with a tiny amount of denatonium benzoate added to make it unpalatable.  There's zero methanol content, which would make it poisonous.

[5U4GB]

If cleaning with alcohol (most should be fairly plastic safe) and detergent doesn't work, then you could try covering it with a lacquer, to encapsulate it.

I wonder if Penetrol would work for this?  It's sold as a flow additive for oil-based paints but if used by itself it penetrates into whatever it's applied to and then when left for a week or so it forms a hard varnish-like surface.  Petrolheads swear by it for protecting rusty surfaces from further rusting, I've used it on rust-prone workshop tools to prevent the rust in the first place.

[5U4GB]

On a similar note, it was mentioned in a previous post about rubber feet. I have a few Racal Dana 1998 frequency counters. A couple of them have metal standoffs at the back to protect the connectors. The standoffs have (or had) black rubber bumpers on them. When I was rearranging my test gear a few months ago, I took the counter off the shelf & stood it up on the floor. When I went to pick it up, it had stuck to the carpet! All 4 bumpers had turned into a gooey mess, like thick tar. Some of it had even run down the back of the counter.

Ugh, I've got some late-90s electric equipment that's done the same thing, it looks like the original material the feet were made from was chocolate mousse.

And some slightly exotic gear from the mid-90s where the manufacturer discovered, some time after they shipped it, that the adhesive on the labels they used would break down over time and eat through the metal enclosure.  Last I heard they had stacks of them in a climate-controlled warehouse somewhere.

[Zero999]

If cleaning with alcohol (most should be fairly plastic safe) and detergent doesn't work, then you could try covering it with a lacquer, to encapsulate it.

I wonder if Penetrol would work for this?  It's sold as a flow additive for oil-based paints but if used by itself it penetrates into whatever it's applied to and then when left for a week or so it forms a hard varnish-like surface.  Petrolheads swear by it for protecting rusty surfaces from further rusting, I've used it on rust-prone workshop tools to prevent the rust in the first place.

I have no idea. I've never heard of it, until now. Going from what I found using Google, it might attach some plastics, but can't be sure either way.

[rdl]

I wouldn't use Penetrol as a cleaner. That's not what it's for. It's some kind of modifier for oil-based paints. It contains only 70% volatile by volume (which appears to be mostly petroleum distillates) that means a large part of it is some kind of solid, or non-evaporating material.

[Zero999]

I wouldn't use Penetrol as a cleaner. That's not what it's for. It's some kind of modifier for oil-based paints. It contains only 70% volatile by volume (which appears to be mostly petroleum distillates) that means a large part of it is some kind of solid, or non-evaporating material.

I think that's the ides: the solid, non-evaporating material will remain on the surface, sealing in the goo. The trouble is the other stuff might attack the plastic.

I was thinking of a spray on lacquer which will dry very quickly and the solvents should evaporate before having chance to damage the plastic.

[Circlotron]

So it might be interesting to see what happens if a sticky case is exposed to strong UV light - is the degradation re-reversible?

I've got a USB stick with this very problem. I've put it in the EPROM eraser for 1 hour and we'll see what happens.

It seemed to improve ever so slightly. Maybe. So, yeah, nah.

[jpanhalt]

If the stickiness is due to UV exposure, you are not reversing that "degradation."  If what you are seeing is real (what were your controls?) you are seeing additional UV "bleach" (i.e., destroy or change) what was made initially.  UV irradiation can be used synthetically, but those reactions need to be monitored/limited so as not to go past the desired point.

I do not think stickiness from such coatings principally is from UV.

 

[AndyBeez]

So it might be interesting to see what happens if a sticky case is exposed to strong UV light - is the degradation re-reversible?

I've got a USB stick with this very problem. I've put it in the EPROM eraser for 1 hour and we'll see what happens.

It seemed to improve ever so slightly. Maybe. So, yeah, nah.

Yah, nah, maybe I wonder how many Joules per square meter of UV + days/weeks, it will take to harden off completely?
We might need one of those industrial steriliser death ray lamps - as seen on @BigClive


YouTube has a few videos demonstrating sticky coat removal: Most involve mechanical rubbing with copious quantities of neat acetone. This does have positive results, but I think the rubbing action is doing most the work, rather than the acetone reconstituting the surface texture. Personally, if you want your lab to smell like a Vietnamese nail bar, then go ahead. Just don't switch on anything that makes sparks

There seem to be two families of soft plastic coating. An inherently soft plastic that's used in higher end devices, such as those Logitech controllers and mice. This plastic seems to sweat plasticiser after a few years of use. In worse cases, it might turn into chocolate mousse. Then there is the soft touch coating used on budget devices, which is aerosol deposited and hardened with UV. It's so cheap, it is not intended to last.

Maybe I'm just being cheap, but I'm experimenting with a safe way of removing the spray on coating: after 24 hours, the talc has captured a lot of the gunk. The talc and gunk mix can be sloughed off without leaving a sea of sticky globs. However, there is still a very thin sticky layer on top of the plastic, which I will treat with more talc. This is rather reminiscent of a car body restoration, where every piece of paint has to be removed. There is no chemical strip option and grit blasting might be too aggressive on a computer mouse.

+EDIT+ I was told of automotive soft touch spray paints which use a chemical activator, rather than UV light. This is a spray paint product available in the UK called Tactile. The link is to the supplier's material safety datasheet PDF, which gives an insight to the chemistry used in soft touch finishes
 - https://cdn.shopify.com/s/files/1/0552/4006/5107/files/MSDS-Tactile-Spray-Can-CP-Ltd-2022.pdf?v=1645203245

[armandine2]

https://www.eevblog.com/forum/chat/overpriced-stuff/96/

.. leave product reviews to shame the manufacturers 

[5U4GB]

I wouldn't use Penetrol as a cleaner. That's not what it's for. It's some kind of modifier for oil-based paints. It contains only 70% volatile by volume (which appears to be mostly petroleum distillates) that means a large part of it is some kind of solid, or non-evaporating material.

I think that's the ides: the solid, non-evaporating material will remain on the surface, sealing in the goo. The trouble is the other stuff might attack the plastic.

Ah, good point, I've only seen it used on metal.  If you want to see a typical off-label use of this kind, google "rat rod".

[Black Phoenix]

I know very well that "rubbery premium touch" on plastics that go bad with time and it is a pain to remove. I have an AKG K845BT headphones who the plastic parts are covered in such soft touch coating that was a sticky mess after some years of use.

My solution was to basically strip everything to the plastic, apply a coat of plastic primer and then 3 coats of black matte paint, together with a light coat of clear matte.

Now it looks even better than before and way stronger than before. Now the other problem I need to solve is that it randomly turns off and on during use, but since it has a 3.5mm jack I can just simply plug in the cable and use it wired until I have the patience to solve his problem.