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Topic: Liquid leakage from parts (Read 2982 times) previous topic - next topic

tripunti

Hi all !

I've a question about my salvaged electronics parts.
In the last year I've harvested a lot of pc parts, like wires, molex connectors, front panels with usb and small displays, switches and so on. I put everything in a box and stored it in a relatively dry place.
Yesterday, I took the box out because I was looking for a piezo speaker. Unexpectedly, a lot of the components and wires were covered by a thin layer of transparent liquid, something that remembers me the liquid coming from leaked batteries.
But there are no batteries and no leaked capacitors in the box!
Note that I stored everything after blowing it with compressed air, so the contents of the box were relatively clean.
The weirdest thing is that there is more liquid around heat shrink tubing on wires  :smiley-roll-blue:

Does someone have an idea of what happened?

Thanks :]

Riva

Where they stored in a cool place and humidity in the air condensed onto the parts when they were bought out into a warm room or are they still damp looking/to the touch?

Peter_n

#2
Aug 09, 2014, 10:48 am Last Edit: Aug 09, 2014, 07:04 pm by Peter_n Reason: 1
No, sorry. I have no idea what happened.
Capacitors can leak. The isolation material around wires can change, making it feel sticky. Chemicals can react and attract moisture.
Perhaps it was sprayed with something during manufacturing to keep moisture away, and that is now attracting moisture. Stranger things have happened.

Is it really on the shrinking tube, or only around it ? A heat shrinking tube has no chemicals to keep it flexible.

Perhaps mice or insects ?

My guess :
30% chance it is chemicals
10% animal/insects
60% something else

tripunti

It is on the shrinking tube, too.
And no, the box was perfectly closed and put in a clean place, so the cause can't be animals/insects.
It has obviously to do with some chemicals, and the liquid isn't water: it has the same smell as a battery leaking (but lighter) and the parts have been left in open air for hours and they have not become dry yet.
I was just curious to know if someone else experienced a similar phenomenon, and could suggest me what that liquid probably is. 

Peter_n

#4
Aug 09, 2014, 07:11 pm Last Edit: Aug 09, 2014, 07:16 pm by Peter_n Reason: 1
"perfectly closed" rings a bell. Any chemical couldn't evaporate and disappear, they were trapped in the box. Perhaps the box itself has chemicals in the plastic. So the box was filled with smelly things from pvc, plasticizers, softeners and so on. Perhaps it was a reaction between a few chemicals. You need a chemical lab to determine what it is, and when you would know what it is, you still might not know the origin, since you don't know which materials have which chemicals.

I know one material that can cause it : rubber or rubber alike material. I have old mice with a "rubber" scrollwheel, that was getting slimy.

Look at the bright side: you could have created a new material. Teflon was discovered like that.

bobcousins


I know one material that can cause it : rubber or rubber alike material. I have old mice with a "rubber" scrollwheel, that was getting slimy.


I found exactly the same thing - the rubber wheel on a mouse I hadn't used for a while seemed to ooze liquid, really quite wet. I thought at first I had spilled something on the desk. The mouse was in open air though.

Some (all?) plastic and rubber materials degrade over time, I've seen them get sticky but this was the first time I seen such wetness. Whether it is liquid from the material, moisture from the air or a combination I don't know.
Please don't PM me asking for help. Ask questions in the forum.

Paul__B

Seems to happen with a certain grey "soft grip" compound.  Some mice themselves - and other devices such as MP3 players - were covered with it and it degrades to a tacky, crumbly mess.  The trick (I have yet to master it) is to clean all of the defective coating  off.

Peter_n

Well, I cleaned the mouse wheel with alcohol with soap and denatured alcohol, and it didn't come back yet.
So the soft plastics being the cause is the only option we have so far ? I think that could be it. I'm not a chemists, so I don't know the compounds.

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