Simple....boiling water with a vial in the center, and with a thermostat monitoring the temp and digital is better. Key is to get the temp close, then put powder on as going over the temp will I.e.
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Start stove boil water...put vial in the center with "water" in it.....monitor temp till it reaches 455 degrees fahrenheit, 235 degrees celsius...(I use a bunsen burner in a lab situation) Add the vial with powder....adjust to the top end of the melting point...if powder melts...then the properties are right. Still might not make it legit but you'll know when you go to use.