[Boatanchors] Part Recovery- (Was "Micamold....)

[David Stinson]

(shared with the group for discussion)

----- Original Message ----- 
From: <hwhall at compuserve.com>

I recall some fellows explaining that they'd recovered carbon 
comp resistors by baking but some (most?) didn't restore 
permanently....
-------------------

The failure mode in carbon comps is different.  Resistors age
"up" in resistance because the carbon "micro-fractures"
and impurities oxidize, creating Hi-Z areas in the structure.
Imagine a large array of resistors in parallel, which is the 
carbon
cylinder inside the part.  Each time a crack develops or an area
oxidizes, some of the resistors go hi-Z and that makes the whole
array go higher in resistance.
Heating might temporarily "mend" some of the cracks,
but they will open again in short order.  Not really "fixable."
GL OM DE Dave AB5S