This helps with adhesion, but can be VERY tricky if you aren't careful. Start by cleaning your parts as good as possible, including any paint, grease or oil. I then like to run the part through the heat and cool cycle once heating the part past the curing temperature of your powder (check your powder bottle for the temperature). I then do one last wipe down with Acetone and then put it back in the oven and heat it to the curing temperature until the ENTIRE part is reading the cure temperature. Using an IR thermometer is key here.