[Boatanchors] Reforming Caps?

[LEE BAHR]

Reforming caps is a hit and miss deal.  Reforming a cap is one thing, but if 
it can be reformed is another thing.  Some electrolytics were made better 
then others.  In some/many cases the moisture has left the electrolytic over 
time.  High grade electrolytics such as military grade caps seem to have 
survived better then others.  The temperature at which the caps were used 
and or stored plays a part too.  The bottom line is, reforming a dried out 
electrolytic surves no purpose.  Manufacturers of the caps had no intention 
of making a cap last 50 years.  (I have smelled many NOS electrolytics which 
are leaking, especially when many are close together in a box).  Today's 
caps are made better then those of old but the manufacturers today still 
don't put 50 year life on their electrolytics.  (More like 8 years).  Your 
budget, availability, and concern for original detail plus the time it takes 
to replace a cap and the risk of what happens to the radio if the cap should 
fail should all play a roll in how you approach replacing or reusing 
electrolytics.   I personally prefer to replace electrolytics whenever 
possible as I don't know how much moisture has left the cap over time.  An 
electrolytic that goes bad can do a lot of damage in many circumstances. 
But, as I said earlier, some of them were made better then others.  Many 
could be perfectly fine today, but how do you really know?  Many have gone 
bad too!  I like to play it safe in most instances by replacing them.  I 
sleep better at night.

Lee, w0vt



> Apologies if this is a controversial question, but am curious about 
> "reforming" capacitors.  I always just replace the wax/paper and 
> electrolytic capacitors without testing them.  Maybe this is sacrilege, 
> and overly cautious, but I’ve always been suspicious of integrity of 4-5 
> decade-old capacitors.  Even if I “reformed” them, would constantly worry 
> about killing a difficult-to-replace transformer sometime down the log. 
> And, I guess my goal is to use the equipment safely and reliably.
>
> But recently, reading accounts from a web page devoted to restoring old 
> rigs, the writer routinely referred to reforming the caps as a normal, 
> routine, and reliable method of dealing with these old components.  I’m 
> willing to learn, so is there consensus regarding reform or replace?  Does 
> replacing these old caps destroy collector's value of the equipment?
>
> Thanks in advance, Curt KB5JO
>