This is actually a serious warning, not a joke. A hardcore collector will probably have observed this phenomenon but might not realise what’s going on. Well, here’s the lowdown!
For the Americans, by polystyrene you call it “styrofoam”. That clears that up for starters.
You may have seen this, you may not. Chances are if you have any boxed consoles, you will. The effect LOOKS as if the polystyrene around wires (gamepad cables, mains wires, RF leads) has melted. Only wires are affected. The polystyrene may be stuck completely to the wire, or it might be carefully removed.
What is actually happening is not related to heat (but heat does in fact speed up the reaction).
The cables are insulated with PVC, this is normal. PVC is made bendy, flexible, by chemicals known as “plasticisers”. They are necessary to give the cables the flexibility and resistance to cracking or drying over time. Without this plasticiser, you’d be having all sorts of troubles with your cables breaking down and even splitting in half! Not good.
But, guess what? Polystyrene also likes plasticiser. It reacts with the plasticiser in the cables on contact, over time. Time meaning months or years.
This results in two problems! The first being the polystyrene “melts” when it leeches the plasticiser, and sticks to the cable. Not only is this unsightly, but also can be hard to remove, sometimes impossible. The second problem, although I havent seen it to this extent, but theoretically the plasticiser could leech into the polystyrene enough to cause the cable to become brittle, and damaged. And for mains cables, that’s the last thing you want!
So – fellow collectors – for that mint boxed NES you have tucked away, have you checked on it lately? You might just want to bag up the wires to keep them out of contact with the poly inner!!