I need to make a coil to test voltage created by flux for a project, but bought the wrong grade of wire. Will the non-tarnishing coating act as a good enough insulator for voltages in the millivolts?
Probably it's a lacquer coating if it's a crafts type wire so it would suffice for a very low voltage.
You can take a couple pieces and twist them roughly together and see if you can measure any continuity between the two. You'll need to remove the coating at the ends to make a reliable connection- soldering heat may well do the trick if it's a polyester lacquer. Be more gentle when you wind the actual coil, obviously.
One manufacturer states that:
The tarnish resistant feature results from an oven-baked clear coat finish