h a l f b a k e r yI think this would be a great thing to not do.
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I read long ago that different metals give off different spark shapes, but I haven't been able to confirm that in modern times. |
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I'm pretty certain that there aren't enough welders around to populate a galaxy - even a mini one. Fortunately this idea is better than the title suggests, although I am concerned that it has probably been done many, many times. |
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There's a problem with this. The very
highest-speed high-speed cameras
usually use a very short-duration flash.
This, for example, is how you get those
shots of apples exploding as bullets go
through them, and stuff like that. |
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To "freeze" very fast-moving sparks,
you can't use a flash, so you would
have to use a high-speed shutter.
That's fine (probably doesn't have to be
that high-speed, actually), but then you
have the problem of getting enough
light into the camera. |
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[baconbrain], you are right. It is possible to accurately tell the difference between different grades of steel with nothing more than a hand held grinder. Each alloy: Carbon, Molybdenum, Manganese, Silicon, etc. gives a very distinctive spark shape, position and colour. For instance, you probably already know that high carbon steels have sparks that fizz and divide many times. Just from memory, I think manganese makes a spear shape at the end of the spark, although don't test me on that. |
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I saw a chart of these, about 25 years ago, but since then, I haven't been able to find a good reference (there are plenty of black and white photos!). A steel producer could check the steel grade just prior to shipping it, without taking a sample back to the spectrographic analyser. |
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The skill is in seeing all those shapes in a fleeting instant, by eye. But now it should be possible to employ a digital camera, and review at leisure. |
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