[sdiy] Carbon foam

[Magnus Danielson]

From: "Mike I" <mirwin at marketbridge.ca>
Subject: Re: [sdiy] Carbon foam
Date: Tue, 6 May 2008 19:31:03 -0400
Message-ID: <000b01c8afd1$40eda180$b4dc47d1 at ca>

> Picked up an old square of conductive foam stuffed with TTL chips at a ham
> flea market... took it out recently and the foam had become crumbly, and the
> IC pins were visibly corroded. On a hunch, tested a moistened piece of the
> foam with some pH testpaper and it was highly acidic... pH around 2 !
> Perhaps it is some kind of polyvinyl chloride that is releasing HCl as it
> deteriorates.
> 
> Horrible stuff.

OUCH! Indeed.

> Perhaps the newer pink colored foam doesn't do this.

Hope so.

> Best to store ICs in the original antistatic tubes.

As I was foofing about the labbench just now, I discovered that one of the
antistatic tube (it's antistatic properties can be discussed as with all older
IC tubes) the end-plugg had deteriarated, so when I pulled it, it broke loose.
The outer part which used to be hard had just became brittle and the inside
soft suspension was not providing much of a resitance either... it just barely
was sitting there... but just a little force caused them to break.

It is obvious that old packing material break and fail. If the components have
any value, replace.

Cheers,
Magnus