"Jim Wilkins" wrote in message
...

If you can't file it, you can't machine it without annealing. It also
cuts through the crud or plating so you can see the color underneath.

I didn't suggest a Dremel because you can't see the tiny sparks very
well outdoors, and some junkyard smells make me nervous about starting
a fire.

***OK, that makes sense.

To measure density with any sort of accuracy you need a balance that
will resolve to at least 1 part in 1000 and preferably -much- better.
For a coin or washer this is about 0.5 milligram, assuming the
displaced water weighs half a gram. You can do better if the sample is
close to the weight limit of the balance.

You don't measure the displaced water, you weigh the part in air and
then hanging in water. The difference in grams equals the volume in
milliliters.

*** Not technically feasible here. Most of the pieces were of the order of
100 gm and my scale weighs to 1 gm. The water displacement was measured with
a 12 cc syringe. Either way, the shapes are irregular and one is always
wondering about air pockets. Some of the pieces I suspect are hollow. So it
is a waste of time either way.

I was fascinated to read in another thread about machinery which can analyze
metal composition by "shooting it" - whatever that means? Does anyone know
how this works?

--
Michael Koblic,
Campbell River, BC