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Comment by chefandy | Hacker News Reader

What’s the liquid in the old capacitors? PCBs? (as in polychlorinated biphenyls… that abbreviation collision always annoyed me.)

I think I know exactly enough about electronics to ask more annoying questions than someone who doesn’t know anything at all.

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Electrolytics are usually nothing too fancy, but it is proprietary. Water and electrolytes, hence the name. PCBs are in the big transformers and what used to be called bathtub caps which looked like this https://i.ebayimg.com/images/g/VjwAAOSwfGJjYtHx/s-l400.jpg (think 1950s electronics stuff)

Thanks!

"Wet" capacitors contain any number of liquid electrolytes. Could be something tame like ethylene glycol, boric acid, sulfuric acid, or nastier stuff like organic solvents (DMF or DMA which are poisonous, or GBL which is less lethal).

Nothing as bad as PCBs as far as I'm aware.

Cool, thanks. I think I should learn how these components actually work. Individually they seem pretty simple.

PCBs were only used in oil capacitors and some transformers. Generally these were used in motor and grid power applications. The only consumer applications are some motor capacitors and florescent light ballasts.

Yeah I pretty much grew up (unknowingly) playing in an illegal unmarked chemical waste dump so it takes a lot to get my attention, but I opened up an old fluorescent desk lamp from the 60s I had that fried itself to see if it was fixable — and found a small piece of crumbly asbestos shielding about the size of a business card stuck to a big leaky ballast. Pretty solid toxic waste combo. City hazmat got a sweet vintage lamp that day, sadly.

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