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JeepHammer, I am truly in debt to you! The tip about the USB camera is priceless - a decent metallograph is indeed thousands of dollars, and even a cheap binocular inverted microscope is on the close order of $2k. I will be trying the USB magnifier for sure!
For etching, search the web for ASTM E407 - even an old version is fine, the compositions do not change, only get more numerous. For brass, potassium dichromate is standard, followed by ferric chloride - dilutions are in E407 but your vinegar (acetic acid) works, just takes minutes instead of seconds.
For steels, 2%- 5% nitric acid in alcohol (known as 'Nital') is pretty standard.
Nitric acid can be gotten from potassium nitrate. Spectracide stump remover is technical grade potassium nitrate (odd, you can get dusting sulfur at the garden store too; and some charcoal, and you have the fixin's for black powder).
And you are absolutely right about the cold-mount plastic. The stuff from the hobby store is precisely what most metallographers use for cold mount. Hot mount is phenolic + pressure + heat (~300ºF) - no need, it is just faster than cold mount, and a little harder (which keeps the edges flatter). Go to buehler.com - they are the best in the industry. Under "Solutions" click on TechNotes and you will find some useful tips and tricks.
Thank you! Now I need to go buy a USB magnifier.
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