Strange reaction between cable and plastic box - Page 1
Forum section: electronics / general

author: ferdieCX
author_rank: Regular Contributor
timestamp: October 15, 2018, 08:34:06 pm
content: Hi, I am a little surprised:About 8 years ago, I bought one of those cheap packs with 10 double alligator test leads.I have not used most of them in the last months and yesterday I wanted to take them out of the small yellow box in the drawer.To my surprise, they tended to remain like glued to the box. The cables have somehow reacted with the plastic material of the box affecting it, as you can see in the pictures.The other boxes in the drawer doesn't seem to be affected.Both the yellow box and the cables where bought in Germany.Has something like that happened to anyone of you ?

author: PointyOintment
author_rank: Frequent Contributor
timestamp: October 15, 2018, 08:41:40 pm
content: Excessive plasticizers in the wire insulation (which is usually made of heavily plasticized PVC)?Also, you're still using an Apple (Pro) Mouse? I haven't seen one of those in years.

author: ferdieCX
author_rank: Regular Contributor
timestamp: October 15, 2018, 08:49:12 pm
content: Quote from: PointyOintment on October 15, 2018, 08:41:40 pmYes, it is an old Apple Mouse, the normal white versionI usually run a CentOS box, but I sometimes use my old iBook G4 when I need a laptopThank you very much for the explanation

author: PointyOintment
author_rank: Frequent Contributor
timestamp: October 15, 2018, 09:01:34 pm
content: I think I've seen this effect before with cheap jumper cables, but I forget exactly where. Those grooves in the box looked quite familiar, somehow. … Oh! I remember: I havea set of breadboard jumper wires, and stored it together with some ofthe cheap alligator jumper cables. The clear plastic box got those grooves in it.Edit: I actually havethe older version of those alligator cables—I don't know if SparkFun's current version has the same issue.

author: Andy Watson
author_rank: Super Contributor
timestamp: October 15, 2018, 09:41:52 pm
content: This:Quote from: PointyOintment on October 15, 2018, 08:41:40 pmI have not seen wires with this problem but those PVC "hoods" for miniature croc-clips definitely do decompose - and eat into almost any plastic that they contact.And watch out for stick-on feet too.

author: tooki
author_rank: Super Contributor
timestamp: October 15, 2018, 09:58:55 pm
content: As you can tell, it’s not such a strange reaction, actually!!One more culprit to watch out for: erasers! Many of them are also highly plasticized PVC (often just called “vinyl erasers”), and they’ll do the same thing. Not uncommon to find a pen cap gone weird after laying in contact with a vinyl eraser for a year or two. I’ve even seen them outright fuse together!

author: sparx
author_rank: Contributor
timestamp: October 15, 2018, 11:36:59 pm
content: Had a mains appliance from eBay (China), the mains IEC lead had welded itself to the polystyrene packaging to the point I was scraping polystyrene off the mains lead.This happens surprisingly a lot - I also bought a (cheapish) neoprene laptop sleeve that arrived stinking to high heaven of chemicals. One wash in the washing machine later, it was a lot more usable.

author: coppercone2
author_rank: Super Contributor
timestamp: October 15, 2018, 11:47:36 pm
content: where are our chinese state sponsored super powers?

author: bsfeechannel
author_rank: Super Contributor
timestamp: October 16, 2018, 12:03:39 am
content: Quote from: tooki on October 15, 2018, 09:58:55 pmHmm. That probably explains what happened when I left one of those erasers unheeded in an organizer for some months.

author: tooki
author_rank: Super Contributor
timestamp: October 16, 2018, 12:11:35 am
content: Yep, absolutely! I’m sure the plastic bin in the OP’s photo would have had the same reaction.

author: Monkeh
author_rank: Super Contributor
timestamp: October 16, 2018, 01:01:40 am
content: Quote from: sparx on October 15, 2018, 11:36:59 pmPS is well known for leeching the plasticizer from PVC violently. It's why they bag the cables!

author: james_s
author_rank: Super Contributor
timestamp: October 16, 2018, 01:19:13 am
content: I've seen the same thing with power cords wrapped around a device made of certain types of plastic. I also had it happen when I left two rolls of different kinds of tape stacked on top of each other.

author: Gary350z
author_rank: Regular Contributor
timestamp: October 16, 2018, 02:29:22 am
content: I have seen this many times.Be careful withanytype of rubbery material in contact with plastic.This can also happen with polyurethane finishes on cabinets or tables.Examples rubbery materials I've had problems with:Erasers, model car tires, rubber grommets, rubber chassis feet, power cords, alligator clip leads.

author: rdl
author_rank: Super Contributor
timestamp: October 16, 2018, 12:23:24 pm
content: In the paint business we call this plasticizer migration. The best plasticizers are usually also good solvents for the substance they are plasticizing. If the plasticized item comes in contact with a similar material, the plasticizer can leech out or migrate from one to the other. Since the plasticizer is also a solvent to some degree, swelling or deformation will occur. Highly polymerized or crosslinked plastics such as polyethylene will be resistant to this effect, while "thermoplastics" such as ABS or styrene are easily damaged.

author: coppercone2
author_rank: Super Contributor
timestamp: October 16, 2018, 12:44:29 pm
content: is this actually normal with properly made plastics?I don't think I ever saw this kind of weird welding effect, other then then wires are sometimes twisted into knots as strain relief (but its in stuff thats like 40 years old).

author: TerraHertz
author_rank: Super Contributor
timestamp: October 16, 2018, 01:46:14 pm
content: Quote from: Monkeh on October 16, 2018, 01:01:40 amBack to front. Expanded PS foam doesn't change the diffusion rate of plasticizers out of PVC. It just has a very small amount of PS (thin foam cell walls) to melt, so the plasticizers have a far more dramatic effect on the PS foam.Plasticizers are *everywhere*. A chemist friend of mine mentioned it's virtually impossible to prepare samples for gas or liquid chromatography, without them having plasticizers contamination.And people wonder why there is a cancer epidemic.The diffusing plasticizers effect I hate most, is the way photocopy toner on pages near the front and back covers of PVC ring binders, gets softened and transferred between paper surfaces. Also sticking the pages together.Second most disgusting effect, is the way some types of aged cable insulation accumulates a tacky surface scum of concentrated plasticizers, which then becomes a dirt sponge, and also transfers to your skin if you handle the cables. Where it does what plasticizers are designed to do - dissolve into organic material and disrupt it's prior structure. Your cells in this case.(ITT, I learned that web spell checkers consider the word plasticizer (singular) to be invalid.)

author: ferdieCX
author_rank: Regular Contributor
timestamp: October 16, 2018, 04:33:18 pm
content: Thank you very much to all of you, this thread has been very informative.I suppose, that self build test cables using silicon cable and test hooks with ABS body are today the only safe option.Quote from: coppercone2 on October 16, 2018, 12:44:29 pmI don't know, but I still have some self built test cables made 40 years ago when I was a student.I never had any issue with them, but the alligators are made in Japan and the cable itself is made in Uruguay.

author: tooki
author_rank: Super Contributor
timestamp: October 16, 2018, 04:58:39 pm
content: Quote from: TerraHertz on October 16, 2018, 01:46:14 pmI remember seeing YouTube videos about some mains wire that, over the years, would leach so much plasticizer that it would drip down the conduit and sometimes drip out of wall sockets/switches!! It would corrode the copper on the way, making it green. I think it was on JW’s channel, so I think UK, but I could be wrong.

author: calexanian
author_rank: Super Contributor
timestamp: October 16, 2018, 06:08:09 pm
content: Some plastics are incompatible for contact with others over time. I just tried searching for it and could not find it, but I used to have a chart with various plastic to plastic compatibility comments. Some combinations would cause that effect, mostly involving ABS, or PVC as one of the components.

author: glarsson
author_rank: Frequent Contributor
timestamp: October 16, 2018, 06:19:56 pm
content: Incompatible plastics can be expensive. About 20 years ago a subcontractor substituted a cheap soft plastic part mounted on a PCB. After just a few years the reaction between the plastic part and the conformal coating allowed moisture to penetrate the conformal coating leading to failures of the engine control unit. The recall involved a huge number of vehicles all over the globe.

author: SeanB
author_rank: Super Contributor
timestamp: October 16, 2018, 06:37:42 pm
content: Quote from: tooki on October 16, 2018, 04:58:39 pmThat was the early generations of PVC wire, with BPA plasticiser that would react with the copper and make the green goo in the walls. Generally any PVC electrical wire made between around 1960 and 2000 would have that occur, only later on did the amount of plasticiser get reduced and replaced with a non BPA based one. Bisophenol A is a known carcinogen, which is why you find so many baby bottles labelled as BPA free plastic, and why so many are made from PET these days and not PVC. A lot of older plasticware however is PVC with BPA in it as plasticiser though, and it is oil soluble, and leaches out into the foodstuffs stored in it.

author: coppercone2
author_rank: Super Contributor
timestamp: October 16, 2018, 08:32:25 pm
content: life in plastic, its fantastic

author: Monkeh
author_rank: Super Contributor
timestamp: October 16, 2018, 11:07:39 pm
content: Quote from: tooki on October 16, 2018, 04:58:39 pmOh yes, I've seen that stuff. Some of the original wiring in my house has done that to a very limited degree over the last 40 years or so. Come across a few places with green goo filled junction boxes.

author: bsfeechannel
author_rank: Super Contributor
timestamp: October 17, 2018, 03:21:44 am
content: Quote from: SeanB on October 16, 2018, 06:37:42 pmThat may also explain what happened to the wires of this old drill (produced somewhere between the 1970s and the 80s). The insulation disintegrated and corroded the wires. I was wondering what might have caused this. Now I know.

author: TerraHertz
author_rank: Super Contributor
timestamp: October 17, 2018, 03:58:39 am
content: Quote from: bsfeechannel on October 17, 2018, 03:21:44 amNo that's a different problem. That insulation was rubber, and most rubber decays over time due to oxidation and de-vulcanizing of the cross-linked hydrocarbon chains of the rubber. Decaying rubber can go through different stages of nastiness - sometimes it goes goey and runs like treacle, then hardens again. Sometimes it just hardens and starts crumbling. As with your drill wires. Almost always the breakdown products are corrosive to any metals in contact. I suppose partly due to sulfur freed up from the broken vulcanization bonds.This is something I'm dealing with atm.http://everist.org/NobLog/20180922_data_in_holes.htm#tm200

author: bsfeechannel
author_rank: Super Contributor
timestamp: October 17, 2018, 04:23:52 am
content: Makes sense.

author: Zero999
author_rank: Super Contributor
timestamp: October 17, 2018, 10:05:05 am
content: Lots of oils can leech plasticisers too, causing cables to become brittle over time. Use silicone rubber or polyurethane sheathed cables to overcome this.Many oils are also plasticisers themselves, some of which are naturally occurring. Orange oil (d-limonene) is a good example of a natural plasticiser. Try rolling some orange rind back and forth, near some polystyrene foam, so it gets coated with a thick layer of orange oil. Leave it for a few minutes and note how it starts to shrink and become tacky, as the orange oil starts to dissolve the plastic.Off topicAnother interesting fact about orange oil is it's an effective insecticide: squirt some on a fly and it will curl up an die. The best thing about it is it's completely non-toxic to mammals, so can be used around food and insects poisoned by it can be safely fed to birds. The only issues are: it dissolves oils in the skin so can cause irritation, in large quantities and it's flammable, like any volatile organic compound.

author: coppercone2
author_rank: Super Contributor
timestamp: October 17, 2018, 01:03:23 pm
content: I assume modern rubber has antioxidants in it that give it longer life?The rubber thing I saw before, usually with coatings on equipment. I had test equipment before that was literarly covered with tar. I did not know what the hell was going on back then, so I actually asked the guy on ebay if he got it from a oil refinery. I thought it was tar that got covered with dust/dirt. I had NO idea that used to be a real coating at some point. It looked like someone pulled it out of a sewer. You could dig your fingers into it and basically expose clean aluminum. It was horrible.

author: tooki
author_rank: Super Contributor
timestamp: October 17, 2018, 01:49:47 pm
content: Quote from: coppercone2 on October 17, 2018, 01:03:23 pmI've seen no evidence of this, sadly.The rubber grips on my old Nikon D70s (bought in 2004 or 2005 IIRC) are starting to go gummy, for example. And the rubberized finish on my Microsoft bluetooth keyboard from around 2010 has degraded much worse, much faster. It's only not sticky because it's collected random dust and lint from being used on the sofa (it's for the Apple TV). So clearly there are huge differences in materials. :/Quote from: coppercone2 on October 17, 2018, 01:03:23 pmOh yeah, I know exactly what you mean. I have an old Sony hi-fi system from around 1993 that had what was once a lovely rubberized finish. Now it's going gummy. (Not nearly as bad as the Microsoft keyboard, though!)

author: PointyOintment
author_rank: Frequent Contributor
timestamp: October 22, 2018, 10:57:26 pm
content: Quote from: tooki on October 16, 2018, 04:58:39 pmIs that also what happens to MacBook power adapter cables around the MagSafe connector? Typically, the insulation frays where it bends, and then sometimes the coax shield underneath has turned green:https://www.ifixit.com/Guide/Repairing+A+Frayed+Apple+MagSafe+Power+Adaptor+Wire/40150Quote from: coppercone2 on October 17, 2018, 01:03:23 pmI've found lots of old equipment (mostly Sun Microsystems) in electronics recycling bins where the rubber feet have turned into a sticky liquid. I also have a Krohn-Hite function generator that has rubber-coated case panels that are a bit sticky by now. Anybody know how to reverse these decays, or at least remove the decayed material?

author: coppercone2
author_rank: Super Contributor
timestamp: October 23, 2018, 02:22:19 am
content: I think I soaked mine in the goopy-methylene chloride stuff used for removing paint and then painted it with galvinized spray paint with some kind of nicer metallic top layer.

author: tooki
author_rank: Super Contributor
timestamp: October 23, 2018, 06:23:16 pm
content: Quote from: PointyOintment on October 22, 2018, 10:57:26 pmNo. There’s no liquid of any kind oozing from those cables. The green is just oxidation of the wire where it’s come into contact with air and skin oils/sweat from using the damaged cable.I’d love to know what those Apple cablesaremade out of. When Apple switched to “environmentally friendly” PVC-free data and power cables*, the longevity of the cables plummeted, because that jacket material is less flexible, so when it fails, it tends to shred into rubbery strands, and it seems to stretch over time. Those MagSafe cables fail precisely because the jacket has stretched so much that it’s appreciably longer than the cable it protects! (I’ve had one where the jacket grew so long that the shreds of failed jacket extended over the strain relief and base of the plug grip!)*Except the AC mains cords. The PVC-free ones are much less compliant than the PVC versions (they want to bounce back to straight or very large coils), but have been holding up very well over time, whereas the PVC ones sometimes go sticky, presumably due to plasticizer migration.I can also conclusively say it’s not silicone, because it melts under the head of a soldering iron.Meanwhile, Apple’s PVC-free earbud wire is also a thermoplastic, but a different one. It fails not brittle, but with the same type of tacky feeling as silicone. If not for the fact that it melts, I would have said it looks and feels like silicone.

author: ferdieCX
author_rank: Regular Contributor
timestamp: October 24, 2018, 12:06:01 pm
content: Quote from: PointyOintment on October 22, 2018, 10:57:26 pmI had this issue with the top and bottom panels of a Philips PE1542 lab power supply.IIRC, I removed the rubber material with isopropyl alcohol and then washed the panels with soap and water.The panels where already mat black painted, so it was not necessary to repaint them.Remember, that alcohol will almost for sure destroy any text or draw present in the panels.

author: PointyOintment
author_rank: Frequent Contributor
timestamp: October 26, 2018, 10:17:37 am
content: Quote from: tooki on October 23, 2018, 06:23:16 pmCome to think of it, mine did that! It's been a long time since then (~2013) and I've been using my MacBook stationarily since then, so the replacement hasn't failed.QuoteI have a set of EarPods from 2013 (I think). Recently, every time I've taken them out of their case, I've found a clear liquid on the cables around the Y-joint, mainly on the thinner ones leading up to each earbud. It wipes off easily with a paper towel scrap soaked in hand sanitizer (which is really good at cleaning all sorts of gunk off of electronics, by the way). I don't know if this is something from the Y-joint, or my own doing: A year or two ago I ripped open the white part of the case (which is just two pieces of plastic glued together) to see how much space there would be inside for a Bluetooth audio receiver. I put some hot glue inside to hold it shut, because it wouldn't hold without glue. The hot glue ended up getting loose, so it's effectively hinged… I need to fix that better at some point. Anyway, when they're wrapped up, the Y-joint rests against where the hot glue is inside the two white parts of the case (not in contact, but on the opposite side of the seam), so it could conceivably be from either the Y-joint or the hot glue.

author: theleakydiode
author_rank: Regular Contributor
timestamp: December 09, 2018, 10:00:07 pm
content: This thread is very interesting, most of my alligator clip covers have turned hard over the years and so do all of my head phone cables.I've heard the latter can be caused by certain skin oils which not everyone produces.

author: Brumby
author_rank: Unknown
timestamp: December 10, 2018, 01:30:06 am
content: I'll just add my 2 cents here by saying - Yep, seen this gooeyness many times.

author: Mr. Scram
author_rank: Super Contributor
timestamp: December 10, 2018, 01:36:11 am
content: I just had the same thing happening on exactly the same cheap type alligator clip leads. It's just cheap plastics venting or leaking rubbish. It's a good reminder why investing in more quality cables is worth it, as you don't want this eating into more valuable kit.

author: coppercone2
author_rank: Super Contributor
timestamp: December 10, 2018, 03:08:53 am
content: hmm good idea maybe to braid wires, if they deteriorate the braid will soak it up. Unless the braid deteriorates. Fiberglass braid

author: Miyuki
author_rank: Frequent Contributor
timestamp: December 10, 2018, 08:11:03 pm
content: If we talking about wires and weird insulation materialsThis "new bio degradable" stuff is greatUsed in modern cars especially German made after 10-15 years look like thisI have same issue in one of my cars, only good thing if I want put cables to recycling center they are already bare copper

author: cdev
author_rank: Super Contributor
timestamp: December 10, 2018, 09:58:38 pm
content: Wash your hands after handling those weeping wires!I would be willing to bet that the many chemicals in plastics, insulation, flame retardants, anti-stick coatings and similar products are behind the big increases in dozens ofexpensive diseasesincluding at least a half dozen different kinds of cancers, we've seen rise over the past few decades, as well as large increases in morbid obesity. (They change the body's energy set points)These so called 'endocrine disruptors' persist in the environment and their measured levels in peoples bodies just keep on rising.We're lucky that CRTs are no longer common- the combination of CRTs(heat) and the plastic cases exposed people who spent a lot of time around them to EDCs.