Newbie/Outsider question: what are resistors actually made of?

Hello everybody! My name is Myria and I really don't belong into this group at all, but I do have a question and searching the web doesn't really get me anywhere, because I guess I lack some basic understanding of electronics. I was hoping you could help me. Simple question: What are resistors actually made of? I mean the inside material. I know it must be some kind of substance that leads electricity more slowly (hope I phrase that right), but I am interested in the actual inside materials. Reason: My husbands grandfather was a radio/TV repair guy from the 50s to the late 80s and we inherited a huge collection of, well, different kinds of resistors (and a couple of capacitators). We couldn't sell them and I was wondering if I could use them in my craft projects. As I am working with children, I need to know if there is anything inside those resistors that is inherently dangerous/poisonous like mercury or maybe lead. And could it be dangerous by contact alone, or if they swallowed a resistor? (They are not that age group, but the weirdest things do happen. In todays suing happy society, you cannot be careful enough!) Any info is appreciated. Thanks. Myria

Reply to
JennaMyria
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The older resistors were mostly carbon in a ceramic(?) shell. The hard shell caps were usually ceramic, too. You may find a few waxy caps, but I can't recall their composition. The electrolytic type caps may have some chemicals in them, but they usually used metal cans as containers.

If the leads have solder on them, the solder likely contains trace amounts of lead. Not enough to be a concern, I would think; you would probably have to be more worried about stomach punctures if one got swallowed.

I've been around components like that for almost as long as grandpa, and it ain't hurt me none!

HTH

Reply to
Randy Day

Carbon composition resistors are a carbon slug inside molded phenolic. "Bakelite". Modern film resistors are ceramic INSIDE. Wirewound resistors (old and new) use ceramics, inside and out. . .

Very old ones will have paper cases with beeswax. . .

Yup. Avoid anything that looks like a canister.

Reply to
JeffM

Thank you all so far! I am however still uncertain. I do not intend to get the kids into electronis, but I really intend the stuff to be used in crafts, i.e. glue them to cardboard or make jewelery out of the stuff!!! And I am afraid that I don't really know what "phenolic Bakelite" is, although I will go and google it immediately. I really just want to know if it is safe to have kids touching those little resistors or having them wear a piece on a string around their neck. Thanks, My

Reply to
JennaMyria

Hi, Myria. The wires coming out of the resistors almost certainly have solder coating on them, which is partly lead. If the children are still small enough to put their hands in their mouths (about 10 to 12 years old, from my experience), they can ingest the lead with possible long-term health effects. If they're older, please tell them washup is required immediately after this "craft" stuff.

The other components may have other toxic elements in them, depending on what you have. Be especially careful with any high voltage sealed capacitors made more than 25 years ago. These usually look like small oblong sealed metal cans with two prongs coming out the top. If you have any of these, you should handle them only with disposable rubber gloves. Place them in a thick plastic garbage bag, and put the garbage bag in a box for carrying. Strip off the disposable gloves and put them in the bag, too. PCBs are absorbed through the skin, and are very toxic.

Actually, it's probably better to just box the whole works up and drop it off at a local trade school or junior/technical college that has an electronics program. As long as you're not looking for a receipt for tax purposes, and you don't give them any '60s or '70s vintage high voltage caps, they'll be happy to sort out what they need and chuck the rest. If you have any of those old HV caps, show them the separate garbage bag/box combination mentioned above and ask them for advice as to proper disposal. These may contain PCBs in their dielectric oil, which causes birth defects and cancer, especially in children.

Good luck Chris

Reply to
Chris

Somehow, I edited out the last paragraph.

It's probably not a good idea to expose kids to old electronics components in a crafts environment. (Of course, if they're interested in electronics as a hobby, that's a different story). If you're thinking about introducing older (13+) kids to low temp tin/lead soldering (possibly metalcraft or jewelery making skills?) it would probably be better just to practice with 8 to 24 gauge solid copper tinned wire. You can strip the insulation off telephone wire or house wiring wire with a wire stripper, buy a small spool of rosin based

60-40 solder and a soldering iron, and you're good to go. I really can't think of any other reason to do this that justifies dealing with lead or the other possible problems. Best just to raise a glass to the old tech, and then get rid of the stuff where it will do some good and maybe help somebody learn something. I'll bet that's what he'd want.

Chris

Reply to
Chris

The same plastic that PC boards and knobs used to be made of. Fred Astaire liked dance floors made of the stuff.

Unless the kids have massive oral fixations and continually suck on the tinned leads (wires with solder on them), as Fields says, it's no big deal. Have them wash their hand before you send them home. (Guessing you already do this.)

Foley specifically mentioned polychlorinated biphenyls (PCBs).

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Yup. I already said that canisters are to be avoided.

Reply to
JeffM

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It\'s safe.
Reply to
John Fields

One day JennaMyria got dressed and committed to text

Also remember that such components are cheap as pollies promises these days :-) If you want to get the kids into electronics spend the money on training, the components are secondary, also the old ones might also be suspect.

-- Regards ..... Rheilly Phoull

Reply to
Rheilly Phoull

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