"They Plump When You Cook Them" - Printable Version
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+--- Thread: "They Plump When You Cook Them" (/showthread.php?tid=10104)
"They Plump When You Cook Them" - Phlogiston - 07-23-2014
For all of you guys that "reform" electrolytic caps, make sure that the form that they take is not this one.
"Yes officer, he was killed by a IED". Improvised Electrolytic Device.
RE: "They Plump When You Cook Them" - jerryhawthorne - 07-23-2014
Phlog, that is what I would call a "reform". Nice job.
Jerry
RE: "They Plump When You Cook Them" - morzh - 07-23-2014
Was that indeed a recently reformed cap or it has been this way awhile.....40-50 years perhaps?
RE: "They Plump When You Cook Them" - Phlogiston - 07-23-2014
I don't reform electrolytic caps. When they are bad they are gonna' swell up and pop. At least that one would render soapy water and some aluminum shrapnel, where as the dry caps have you cleaning up gooey paper everywhere.
RE: "They Plump When You Cook Them" - morzh - 07-23-2014
Well, reforming of new caps simply puts them against the working voltage and the rate of current drop is watched, and the old ones are put via large value resistance so if the cap shorts the current is in single mAmps.
Caps blow up. I saw ceramic caps go up in flames and burn holes in fiberglass.
All can happen.
RE: "They Plump When You Cook Them" - codefox1 - 07-25-2014
Yup, glad I had my glasses on when one popped on me all those years ago. Kind of scares me, as eyes change, and I no longer need reading glasses, which is a danger to me at the bench.
Of course I would not try to fire up one of these old timers anymore. Please, everyone don't do it, Many of these sets were not fused, and fire and injury risks aside, expensive/irreplaceable transformers may be destroyed in the process.
It is true that old caps that are used on a regular basis last longer than those that were neer used and end up in a bin for salvage, I never leave the room when sets using any antique components are running..
Hope to see all of you back on this forum next year.
RE: "They Plump When You Cook Them" - morzh - 07-25-2014
I do not reform old Philco caps from 30s or 40s. Especially in view of the fact they have no capacitance left due to drying.
But caps from 50s and 60s that exhibit full capacitance I try to revive.
Especially that one from Western Electric oscillator I fixed, it was ome mil pec, it reformed to better leakage than a new cap today might have.