Vintage electrolytic capacitors

[Funker]

Ok people, I'm starting this thread because I didn't find old posts about this.

Bought a stock of old electrolytic capacitos, even knowing that these degrade or gone dry with time, expecting that at least some of them still work, because i think they look cool, specially those TESLA with the screw on the base. The problem is as you would imagine they are built in a country that no longer exist as such (Czechoslovakia) and others made in England which still exists, though my guess is these are at least 35 to 40 years old.

Tried a few 16mF + 16mF tesla brand with 100V DC and they get warm, possibly behaving more like a resistor than a capacitor.
I have a good analog multimeter and a digital multimeter that measures capacitance up to 22mF. Still I don't know a proper way to determine if a cap is good or not to be installed.
Ideas?
Pics are related.

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dirt.

An externally hosted image should be here but it was not working when we last tested it.

Hi Vmunix,

I suggest that you should not use these capacitors to build new equipent with. You might check them, formate them and use them eventually to repair vintage radios gear.
It is no need today for using old and worn out capacitors. What Gregg wrote, old capacitors contains unknown and probably toxic chemicals which can serious ruin your health, especially in the event they explode and splatter its content around your place.

Use new ones . Capacitor for higher voltage are today common since the use of switching PSU. They are easily obtainable at your local electronic shop.

@Gregg:

Wonder what a big one would look like..

Happend to me several years ago. I tried to build up a reactance circuit for an AC power inverter. I tweaked the resonance by feed the series resonance circiut with mains ac. I concentrate myself on the ammeter and fiddle paper inbetween the Inductor gap. At the point of where the circut draw an immens portion of current near its resonance , a big bang shuttered my workshop and things are flying around my head. The 33 µF Bosch MP capacitor was exploding and sweeped most everything from the bench. And not I´m was really awfully shocked , finally to top all this mess unneccessarily my mother turned up and railed against the noise and smell.

Me , my tools and and most of my testgear was overcast with a squidgy smelly matter. It was the oil which are the Bosch MPs filled. These Bosch MPs are better known as Motor starter capacitors and reactive current compensators in flourescents lamp fixtures.

73
Wolfgang