I have found that both statements from fishhunter775 and Fatman are correct. Lower temp and longer time works for tricky colors or items like glitter that might melt. Technically you should not have to do the dip in clear after the glitter goes on, but have found it helps if you are using large size glitter to smooth everything over. Also makes anything that has mics/pearl powders mixed in a gloss finish if you do a quick dip in clear at the end. Sometimes i add the final clear dip sometimes not.
I have 2 guesses as to what happened with those. - EITHER - head was too hot when you dipped the final clear coat and let way too much powder stick - OR - your oven got too hot too fast and let the powder liquefy and 'flow'. Actually would guess a combination of the 2.
For any dipped layers of powder or even tapped, only heat the head hot enough to JUST STICK the powder and not completely gloss over right away. If it glosses over right away, it is too hot and will stick a chit-ton of powder and make nips and drips happen more easily during cure.
As for the cure, i have found a way around the drips that so far works pretty well even for thick layers of powder. Used to stand them up vertical to avoid nipple heads, but now hang them all. Even paint my own powder eyes and seldom have them run or sag anymore.
Hang the heads and turn on the oven to around 250°. Let them go at that temp for about 10 minutes. Then start to raise your temp SLOOOOWLY. I bump it up about 10° every 2 minutes or so. Once i get it up to 340°, set the timer for 15 minutes. In my mind, i believe this lets the powder start to cure some at the lower temp and holds it in place better once you get up closer to the final cure temp. Sounds complicated, but i just paint while they cure and keep an eye on them. The cure process takes longer but you will be grinning like a mule eating briers after you see the quality.
