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Old 4th August 2003, 10:42 PM   #1
grataku is offline grataku  United States
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Default Lifespan of old oil caps

I have a chance to acquire a few old oil caps... you know the ones in the steel rectangular can. However, they are quite dated I wonder about their lifespan.
Same deal for the old sealed transformers in steel box. I especially wonder about the lifespan of the dielectric. Since they are sealed it is concievable that oxidation and free radicals degradation are kept to a minumum.
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Old 4th August 2003, 10:49 PM   #2
SY is offline SY  United States
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Just about forever. Metal is a GREAT barrier material.
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Old 4th August 2003, 11:15 PM   #3
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Hi,

Basically, they should last forever...xformer either work or they don't.

Oil caps? As long as they don't leak...same thing really.

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Old 5th August 2003, 12:06 AM   #4
grataku is offline grataku  United States
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How do they rate of the sonic scale in tube amp PSes? (the caps I mean)
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Old 5th August 2003, 12:15 AM   #5
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Hi,

Quote:
How do they rate of the sonic scale in tube amp PSes? (the caps I mean)
Second to polyprop in oils...not that I don't have my own recipe on this including dirty old eloctrolytic caps?

Confused? Don't be...

Just don't make a common mistake by using the best cap everywhere...let me restate that; use the best cap for the job everywhere and you'll notice it won't the same technology all 'round.

Horses for courses, mes amis.
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Old 5th August 2003, 05:58 AM   #6
SHiFTY is offline SHiFTY  New Zealand
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Before you obtain them, check that they don't contain PCB (polychlorinated biphenyls)

PCB oil was widely used in old caps and transformers, and should be avoided because if it burns, it releases a highly toxic & carcinogenic byproduct.

They have to be sent for specialist high-temperature incineration.

If the cap has a name/brand/date code on it, you can download a list of PCB-containing caps from the internet.
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Old 5th August 2003, 07:57 AM   #7
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Quote:
Originally posted by ShiFtY
Before you obtain them, check that they don't contain PCB (polychlorinated biphenyls)
I have some of these, and as the cans are solid and intact, why not use them? The stuff is safer inside the can and isn't causing any pollution where it is. Mine are mounted with the can seal and the terminals on top, so it's not likely to leak anyway.

One of my (former) neighbours is a HAZMAT specialist with the FB, and he told me basically the same thing. There would be a huge amount of transformers etc in the mains system that still have them.

Of course be careful and sensible with them.
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Old 5th August 2003, 10:03 PM   #8
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Hi shogun Brett,

Quote:
Mine are mounted with the can seal and the terminals on top, so it's not likely to leak anyway.
And that is the only way they should be mounted.

You sure know your stuff.

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Old 7th September 2003, 06:20 AM   #9
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Hallo everybody,
What if a oil capacitor is leaking, but not seriously. What should I do with it? Throw it away?
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Old 7th September 2003, 08:55 AM   #10
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How I rate the sound? Preferable to poly in oil not as good as Black Gate WKZ, but all oil caps sound different certain ones are best in certain situations as is found with all types of cap. The secret to a rich empirical knowledge base is to buy as many as you can get your hands on and try them in as many places as you can, until you find out for yourself what sounds best where. If you don't agree with my ranking, form your own empirically and tell us about it, we may be inspired to try for ourselves what you have discovered for yourself.

How I deal with the pcb issue? When I was a nurse I handled a leaky pcb cap, so I telephoned the poisons unit at Guys Hospital where British Doctors go for guidance in the event of substance ingestion. Their response was "Nothing to worry about in the case of occasional contact", the technical term is "low acute toxisity". I asked what that meant. "It is not considered safe for people to handle it continuously in say a manufacturing process but the occasional contact by a user is not considered by Guys Hospital to be serious.

Yes I understand that in the USA environmental issues are more ruggedly enforced.

As regards disposal, do you have an equivalent of our environmental health department? Ask them. I would expect here I could phone the local council and say I have some old leaky capacitors with pcp's could you come and take them away to dispose of them appropriately? I'm sure they would oblige.
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