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Bronze: potential health issues?


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Hey guys, I'm wondering what the health implications of Tin Bronzes are. The easiest to get for me is 660 "High leaded tin bronze" which is pretty clearly a health hazard, but what about plain old tin bronze? Is that a safe material to handle on a regular basis? Let's say a knife handle (or something) were made out of bronze. It would be in frequent contact with the user's skin. Is this hazardous? Are there bronzes or bronze colored alloys which are safer in that regard?

 

Thanks, and sorry if weird question...

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Silicon bronze is fairly safe for most casting/working, and is not hard to order online. 

 

A big thing to watch out for is zinc poisoning, which you can get from a lot brass or "bronze" alloys by breathing the fumes when they get hot. There's even what is sometimes called architectural bronze, which is often straight copper and zinc.

 

Zinc poisoning feels very similar to an instant case of flu/pneumonia, and in severe cases can kill you.  Not unheard of for people to get it even from welding or brazing. Best to use good ventiliation and take precautions when working with unknown alloys. When in doubt, better safe than sorry.

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Think of it this way......When you wear a bronze/copper braclet or ring it turns your skin GREEN. When you inhale fine particles of bronze from polishing or fine grinding it's doing the same thing inside you.....no bueno! My Father in law was helping me finish a bronze railing once and the ol' cuss wouldn't wear a mask even after I warned him. The next day he was a believer, said it felt like he'd been kicked in the chest by a horse.... ;)

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The most common type of traction/hard facing that farriers apply to horseshoes consists of tungsten carbide particles cast into a rod and bound into a braze metal matrix. I used to apply it with a torch which put me right over the fumes. Since I was normally outdoors, it wasn't a real problem, but I now break off pieces of the rod, place them on the shoe and melt it in my gas forge. An amazing amount of white zinc oxide will coat my forge above the opening. True Borium hard face has the particles in a steel tube and must be applied with a torch, but doesn't have fumes. I don't know all of the alloys of brass/bronze, but some are pretty nasty for either heating or grinding.

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Right. It's easy for me to make the choice to protect myself from fumes and dust (which I do and will continue to do), but its another thing it the finished result is unhealthy to touch. Am I right in assuming that if I wanted to make something like a bracelet or the handle for something from bronze, the safest bet is to go with silicon bronze (with no other alloying element)?

 

I found alloy C873 locally, it claims to be 95% Copper, 4% Silicon, and 1% Manganese I believe...


Thanks

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I have done casting for years and have used "bronze" in jewelry for awhile now. When I first started out casting I used scrap brass, plumbing fixtures, cartridge brass, etc. and whatever else came along, the results were not always pretty. I next tried mixing my own alloy by purchasing pewter mugs from second hand thrift stores(98% tin) and using electrical wire(99%copper) making my own bronze, better results but still not as good as what one gets from using a good quality silicon bronze, really nice stuff. I haven't had any complaints from folk wearing jewelry made from it next to the skin and it doesn't seem to leave a green stain on the skin either like brass, copper or traditional tin/copper bronze either, I suppose it all has to do with the silicon. If you want good quality pours you need good   quality metals and this is especially true if you are working in your backyard and want to avoid problems. One tool that I have never regretted spending the money on was my immersion pyrometer to gauge the correct temperature of my molten metal. It has been an indispensable tool.

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