Paper capacitor longevity
 

After rebuilding a couple little radios here, I have run dangerously low on .047uf capacitors. On a whim, I punched it into eBay to see what was out there. I was amazed that it came back with a lot of results - for paper capacitors! Old stock, paper in oil capacitors. How can these still be good to use? I know that the paper in oil caps are somwhat better than the common paper in leaky wax capacitors, but surely these will have suffered a similar degridation over the years. I know, that if they were stored properly, they will probably work fine, for a while anyway. But for how long? How long can a paper capacitor, or paper in oil capacitor, be expected to last if not used?

Or is there something I'm missing?

Either way, I think I'm going to stick to orange drops and those little yellow guys.

-Ian

I see NOS paper capacitors on epay all the time. I've seen those "bumblebee" caps go for big $$. Some tube amp people claim that these old caps make the amp produce a different tone that is better than what the current caps provide. Those "bumblebee" caps are almost always leaky; so, I guess they would cause an amp to have a different style sound. I would never use those old style capacitors in anything I was repairing because of performance & safety issues. I've got a bunch of old "bumblebee" and other paper caps that I have cut out of equipment. My bad side says list them on epay and if someone wants to run the price up for old caps, then, so be it. OTOH, my good side won't let me list them because of the safety & poor performance issues that I know these cause. For me, I'll just keep ordering the little yellow ones and the orange drops. They are still cheap enough that I can re-cap a radio, amp, etc. and not feel the pressure on my wallet.