I was just reading on the Antique Radios Forum in the test equipment section where the moderator says electrolytics have bubbles in them. The bubbles form an insulation barrier so the electrolytic don't short out. These bubbles break when the electrolytics are not used and have to be replaced by running a small current through them, this is called reforming.

I always thought the aluminum oxide layer broke down and had to be replaced, which can be done with a small current over a period of time. Reforming is done to replace the oxide layer, not make insulating bubbles.

I have never heard of the bubble concept, sounds like a fairy tale to me. Or perhaps too much bubbly. (pun intended)

Confused

I think you are right about the "reforming" process. You are actually restoring a thin film of aluminum oxide. I have heard old-timers talk about bubbles in the old wet electrolytic caps, but the following website gives a good explanation:

http://www.elna-america.com/tech_al_principles.php

Rich

:I was just reading on the Antique Radios Forum in the test equipment section where the moderator says electrolytics have bubbles in them. The bubbles form an insulation barrier so the electrolytic don't short out. These bubbles break when the electrolytics are not used and have to be replaced by running a small current through them, this is called reforming.
:
:I always thought the aluminum oxide layer broke down and had to be replaced, which can be done with a small current over a period of time. Reforming is done to replace the oxide layer, not make insulating bubbles.
:
:I have never heard of the bubble concept, sounds like a fairy tale to me. Or perhaps too much bubbly. (pun intended)
:
:Confused

You are right, there are no bubbles in a electrolytic, the aluminum oxide layer provides the insulation. I have never heard of the bubbles concept.

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