[ARC5] Re-stuffed cap

[J. Forster]

Problem is the lip is very highly deformed and work hardens badly. If you
can straighten it out, it might well be wise to anneal the can lip before
crimping it back.

-John

================




>
> Ken -
> To bad an electric can opener could not be used to open then close the
> lips on these puppies?
> Some one with a lathe could make an slope-ie L shape to open then pop
> the wheel off and lay down  L to  close them up.
>
> Electric can opener?
>
> -Hutch
>
>
> On 3/30/2011 1:36 PM, Kenneth G. Gordon wrote:
>> Later this evening, I'll post the article and photos of my latest
>> re-stuffing job
>> to my website.
>>
>> Although this first attempt looks "acceptable" and works well, it does
>> not look
>> as good as I think I can make them. I would like to make them look
>> identical
>> with the originals, but may not be able to.
>>
>> I am working on another one, which, by the way, was made by Aerovox. The
>> previous one was made by Sprague. Both appear to have been built
>> identically, probably according to either A.R.C. or military
>> specifications.
>>
>> However, the Aerovox cap was MUCH more deteriorated, both internally and
>> externally, than the Sprague. All the individual caps in the Aerovox cap
>> were
>> completely "soaked" in green corrosion, and the connections to the ends
>> were all loose. They ALL came loose with a very slight tug on the leads,
>> and
>> the interior of the brass pot was covered in green corrosion, which was
>> very
>> difficult to clean out.
>>
>> I have tested the Sprague cap that I finished, and have found some
>> interesting things:
>>
>> 1) there is considerable capacitance measurable BETWEEN each of the
>> three disk ceramics, even the "outside" two, in the restuffed cap: about
>> 0.025
>> mfd between EACH 0.05 mfd cap, almost exactly 1/2 of the capacitance of
>> each individual cap. I installed all three disc ceramics "facing" the
>> same way.
>> In the next one, I'll reverse the center one to see if that makes any
>> difference.
>>
>> 2) When measuring the originals, there was ALSO just about 1/2 the rated
>> capacitance between each of the paper caps. I wonder if this was a
>> "designed-in" feature of the original circuitry? If it was, i wonder
>> what its
>> purpose was intended to be? Maybe it doesn't matter?
>>
>> 3) There is no measurable leakage at 450 VDC (the upper limit for my
>> C-3)
>> between any of the three caps. The capacitances between them, again
>> 0.025 mfd, have identical leakage as that of each individual
>> cap....essentially
>> none.
>>
>> 4) Although I did this first job in several sessions, I suspect that if
>> I were to sit
>> down and complete one, from start to finish, it would take a little over
>> 1 hour
>> apiece.
>>
>> Does anyone know that these brass pots were plated with? Zinc? Some
>> other metal?
>>
>> Is it worth it? I don't know, but it is certainly interesting...
>>
>> Ken W7EKB
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