Anyone have an idea if the brass rings that are used by Hung gar practitioners contain lead or other harmful metals?(cadmium, nickel..) I purchased a set a couple of years ago and now I am wondering...particularly after the recall of products from the PRC containing such metals. Wikipedia does state that lead tend to migrate to the surface of brass as well. Any info let me know.
Since you already have a set you might get one of these test kits. (http://www.google.com/products?client=firefox-a&rls=org.mozilla:en-US:official&channel=s&hl=en&q=lead+test+kit&um=1&ie=UTF-8&ei=ujzLS4S5GoWmswOLxIiWAw&sa=X&oi=product_result_group&ct=title&resnum=1&ved=0CCwQrQQwAA)
Thanks for the link. I will give this a try.
Check across the welds especially.
I will check them, I assume they are along the outer circumference of the ring. I was actually under the impression that they are cast in say a sand mold in one piece from molten brass?
On a separate note I did have one crack recently and had to refill the crack by filing the crack open and then filling it in using a propane torch and some tin-silver solder. Seems to be holding up well. That particular ring had an air void in it that I believe lead to the fracture.
They are usually a rod bent into a ring then welded.
I am surprised that you were able to fix it, brass is notoriously hard to mend as the percentages of the alloy could be all over the place.
They might give off whitish smoke when heated for solder, this stuff is usually the zinc and should not be inhaled.
I had to do quite a bit of cleaning to get a good bond as you might guess. I filed the crack open, polished it with 180 grit sandpaper, cleaned it with acetone and then treated the area with dilute hydrochloric acid.
I did not see any zinc fumes but I am assuming that is because the solder flow temperature is 240C (approx 480F) below the zinc evaporation threshold.
I was not aware that they are made from brass rod. It makes sense that the stress crack occurred along the welded seam. I am not looking forward to nine more fractures though. I have even started looking into molding my own rings by sand casting.
Thanks again for the info.
Gotcha, sounds like you have handled a torch a few times before, plumber? Welder?
I was picturing someone with a Costco mapp gas kit roasting the crap out of one of those rings.. :)
If you do decide to cast, i am sure you realize the brass will certainly give off zinc smoke, so have ample ventilation.
I could see a cottage business there.
I worked mostly with glass in the past. I think I'll post a pic of the ring once I find a camera.
Cool, ftr i did ask a metal worker friend of mine about lead in brass and your concerns are indeed well warranted.
Even here in the US, brass rod can often have lead in it.
Whatever method was originally used to join the ends is suspect as well.
Just found a government report on how commercial lead test kits, even when they indicate a positive for lead, have a significant probability of being incorrect. The same is true for a negative test result for lead.
They recommend sending the sample for test to a lab rather than using the solution(tests requiring liquid indicators) based ones. What also complicates the test is that some forms of lead do not dissolve in the test media leading to no detection and that iron in a sample can yield a positive test. Check out the report below.
BTW I have pictures of the mended brass ring, just trying to figure out how to post them.
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