[AMRadio] Oil filled capacitors

Thomas Adams quixote2 at ix.netcom.com
Sat May 17 18:42:17 EDT 2008

At 04:29 PM 5/17/2008, Rick Brashear wrote:
>Has anyone had any experience with leaky oil filled capacitors?  I have
>several I have been going through and a couple have slight leakage around
>the terminal.  I know the oil could possibly have some kind of no-no
>properties, but I am more concerned with the mess they make.  Has anyone
>ever used JB Weld or epoxy to seal the terminals?  The capacitors check out
>just fine under heavy load, but I don't want that gook all over the
>transmitter and I fear if it were to short out it might make a real mess!
>Any suggestions?  I'm too cheap to just throw them away.

I used to work in a cap factory's quality control and testing department.

This isn't what you wanna hear...  throw 'em away.

You don't know how long the caps have been leaking, and how much oil is gone.
If any capacitor sections, or parts of them, are exposed to air, 
you've got a big

On more than one occasion I've done hi pot tests on caps that, thru 
error,  were
not completely filled. What happened was the exposed section ends flashed
over, oil vapor and waxed paper made dandy fuel, and the resulting flashover
caused a small explosion in the can that blew the top off...  with considerable
force, I might add.

In a rig I had in high school, the same thing happened in a 500 watt 
813 CW rig.
The cap in question was about 4 MFD @ 4000 VDC.

Ever seen a 5 foot relay rack jump two feet in the air?


Mr. T., W9LBB

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