Summary for mystery metal sanding Discussion
Strange taste & throat closing while wire sanding mystery metal centers on Gilbert O'Sughrue’s concern after brushing an old, shell-shaped metal object found under a deck. He thought it might be pewter because it was light, silvery, yellowing, and had rusty-looking and green corrosion spots, but the Dremel brushing produced a dark gray or silver finish and triggered throat-closing symptoms, so he stopped. Ted advised that no sanding or brushing should be done without at least a disposable dust mask, since all dust is harmful to breathe. He said the metal could be aluminum, zinc diecasting, pewter, or plated with copper and nickel, and warned that the brown and green corrosion could also fit cadmium jewelry plating. Because cadmium is a bio-accumulative poison, Ted suggested having the metal tested by someone in a lab or scrapyard, or considering a doctor visit for a cadmium blood test if symptoms continued.
Q. Hi everyone, I found a metal object in shape of sea snail shell under a deck. It looks old. The metal appears a silvery colour but is yellowing. There are rusty looking (but I don’t think it’s rust) areas, some small green corrosion areas too. I was guessing it’s pewter. Metal is not very heavy for it’s size.
I washed the shell with dishwashing liquid. After drying I used a dremel
⇦ on
eBay or
Amazon [affil link] with stainless steel brush to start removing yellow colour and corrosion. Cup shaped brush turned metal a dark grey. Wheel shaped brush turned metal a silver colour.
I started on underside as precaution but started to get symptoms you see in the heading, so I stopped and looked you up! What type of metal do you think I’ve found? Do you think a liquid solution (like vinegar) would be safer? etc?
Gilbert O’Sughrue
– Auckland, New Zealand
April 21, 2024
A. Hi Gilbert. First things first: I don’t care what you’re sanding or brushing — wood, paint, ceramic, metal — never do so without wearing at the very least a disposable dust mask, even a 3-for-$1 Covid mask if you have nothing else. No such dust belongs in your lungs! Every single one of them is bad for you.
I don’t think anyone can guess what metal it is. It might be a plain aluminum or zinc diecasting, or pewter; it might be any of them with a copper & nickel plating on top (would explain the brown and green). The concern for me is that it just might be copper & nickel plating on top of cadmium jewelry. Cadmium is, like mercury and lead, a bio-accumulative poison. Just a few years ago Walmart sold cadmium children’s jewelry.
If you know anyone working in a lab or a scrapyard you could ask them to test the metal for you. Otherwise, although your symptoms could be from a relatively harmless metal or partially psychosomatic, if you wanted to go to a doctor for a cadmium blood test that doesn’t sound unreasonable to me.
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.
Thank you for your quick reply Ted.
Yes sir, I will adopt a mask wearing habit forthwith!
I doubt it’s aluminium. I don’t really know anything about nickel and will use this as an opportunity to research it.
I may be able to get a test done by a local scrap merchant, who once offered me a job.
Great site! Thanks again,
Gilbert
Gilbert O’Sughrue [returning]
– Auckland, New Zealand
April 22, 2024