Hot coat is a Heat gun activated powder. I use a 1500 watt heat gun (a very cheap one from Harbor Freight tools).
I use on baked clay only. I used on top of silk screen acrylic painted baked pieces.
I heat up and roll beads in powder, flat pieces i sprinkle with a confection dusting wand.
As with all powders you want to use in a well ventilated room and with a mask on. Always store powders in cool (less than 80 degrees Fahrenheit) dry (60 percent or less humidity) well ventilated area away from heat sparks and open flame.
Heat up clay item before applying powder.
I place on ceramic tile before heating with gun.
Do not flip over piece to apply on the back, the front coat will melt and stick to your surface.
Tap off excess powder, its better to apply more coats then get a bump!