My feet are melting - Page 1
Forum section: electronics / general

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: February 16, 2012, 10:29:40 am
content: Noticed this wierd thing happenning to some very old stick-on PVC (I think) feet - timescale maybe 10-15 years at room temp

author: BravoV
author_rank: Super Contributor
timestamp: February 16, 2012, 10:35:02 am
content: Bio degradable ?

author: Mint.
author_rank: Frequent Contributor
timestamp: February 16, 2012, 10:36:54 am
content: Quote from: BravoV on February 16, 2012, 10:35:02 amGood guess, I agree. Perhaps it is.

author: Mechatrommer
author_rank: Super Contributor
timestamp: February 16, 2012, 10:42:58 am
content: Quote from: BravoV on February 16, 2012, 10:35:02 ama reason for "time to buy a new one"

author: Balaur
author_rank: Unknown
timestamp: February 16, 2012, 10:48:50 am
content: Yeah, I've seen that happening several times. The rubber feet from my old (8+ years) laptop (acting as a server) fused to the docking station at some point. When I've tried to unplug it, it was like a very stringy cheese sandwich.Foam-based stuff is even worse: earphone foam pieces decide to spontaneously deconstruct themselves, various foam-backed trim elements from my car deconnect from their support and started exhaling a rather unpleasant dust and so on.Cheers,Dan

author: BravoV
author_rank: Super Contributor
timestamp: February 16, 2012, 11:01:17 am
content: Quote from: Mechatrommer on February 16, 2012, 10:42:58 amIn the future we might hear something that sounds like this ......."Kid, in the good ole days, you can collect a really good & reliable scope that will last very long, but now, god damn it, just look at that good dso, its working fine but its melting like an ice-cream."

author: Jad.z
author_rank: Regular Contributor
timestamp: February 16, 2012, 11:40:17 am
content: Quote from: Big Site of Amazing Facts link=www.bigsiteofamazingfacts.com

author: G7PSK
author_rank: Super Contributor
timestamp: February 16, 2012, 11:54:09 am
content: Chlorine also makes rubber decompose so if cleaned with a chlorine containing product it could start to decompose, I believe that they put bleach onto the tyres of drag racers or the track at the start as this softens the rubber to give more grip.

author: wkb
author_rank: Super Contributor
timestamp: February 16, 2012, 12:33:18 pm
content: Quote from: G7PSK on February 16, 2012, 11:54:09 amBleach (sodiumhypochlorite (spelling?) solution in water) does not decompose rubber. Otherwise rubber gloves would disolve quickly on the hands of your local cleaning ladyVulcanised rubber is quite stable, things like UV light, oxygen etc can degrade it but only over time

author: G7PSK
author_rank: Super Contributor
timestamp: February 16, 2012, 04:02:23 pm
content: Quote from: wkb on February 16, 2012, 12:33:18 pmRubber gloves are not made of rubber or at least not pure rubber. Pure latex breaks down fairly fast in strong chlorine compounds especially at elevated temperatures. Also when you use household bleach with your marigolds on the bleach will be diluted and you or your wife will rinse the gloves after use in clean water. If you read your washing machine or dishwasher instructions it will tel you not to use chlorine bleach, this is due to the chlorine degrading the rubber seals and pipes.I looked up what happens with rubber and chlorine, The chlorine replaces some of the polymer bonds.

author: nessatse
author_rank: Regular Contributor
timestamp: February 16, 2012, 04:54:35 pm
content: Rubber also does not like being in contact with lacquer paint (as found in spray cans). I almost ruined a lacquered guitar by hanging it in a rubber hanger. I have also seen this happening to old modems that had been standing on a painted metal shelf inside a cabinet for a few years.

author: Mint.
author_rank: Frequent Contributor
timestamp: February 16, 2012, 09:54:59 pm
content: I had a similar "issue". I recently bought an old cassette tape player. It had foam bits inside which I assume were for vibration and shock dampening. Upon opening the player up the foam pads fell off and crumbled.

author: wkb
author_rank: Super Contributor
timestamp: February 17, 2012, 05:58:30 am
content: Quote from: G7PSK on February 16, 2012, 04:02:23 pmLatex gloves are a verry different thing than proper rubber gloves. Latex breaks down with other chemicals than chlorine, IIRC acetone and MEK for example. Rubber is also a common name, covering both natural rubber as well as highly stable artificial rubbers. When handling any chemical one should ensure gloves are used that are suitable for the chemicals bing handled AND suitable for the concentrations of said chenicals AND suitable for the contact times for those chemicals. In some cases chemicals over a longer period penetrates a glove, while at the same time are OK for short term exposure. Same goes for concentrations, good example being sulphuric acid. Not too bad (still hazardous though!) in concentrations used in car batteries, but horrible stuff in concentrated form, let alone in its 'smoking' form.So, normal household concentrations bleach are not a problem for sensible household gloves. Latex is not sensible stuff for work like this, also for reasons of mechanical strength btw.

author: amyk
author_rank: Super Contributor
timestamp: February 17, 2012, 10:22:44 am
content: Possibly it was stored in an environment with gasses that attacked the material and caused depolymerisation.

author: im_a_human
author_rank: Regular Contributor
timestamp: February 17, 2012, 01:07:19 pm
content: My very old fluke multimeter probes kept making a sticky liquid whenever they were put into the probe clips on the holster. It was only this one set of probes that did this as i have another set of the same probes. I figured it was due to the materials in the holster and the probes causing some kind of chemical reaction.Another thing is whenever cables and wires of any type touch walls the paint always comes off on the wires, weird