holy shit, it always trips me out reading paint threads on forum. to the op, i know you got it fixed but your problem was in how you were spraying it. nothing to do with prep. you probably put to many or to heavy of coats on. it either blistered or etched into the taillight. its hard to tell. in the pics. heres a how to on kandy or tinting a taillight.
- you can use a gray scotch bright and some dish soap, and scuff the piss out of what you want to paint. i guess if for piece of mind you wanted to use sandpaper, you could use 1000 wet sanding. i generally end up clearing the whole taillight so i usually prep the whole light.
- when the taillight is dry tape up what you dont want to kandy or tint, generally just the reverse light. your going to be kandying the whole taillight to make sure the kandy is consistant. get a fine line tape to go around the boarder of the reverse light, then cover up the light inside the fine line tape. fine line tape will leave a "softer" edge when the paint butts up to it.
- wipe it down with wax and grease remover.
- spray adhesion promotor on there. dont spray this like your trying to paint something just put a light to medium coat on there. i cant remember if i usualy use adhesion promotor but it wont hurt to use it.
-now spray your kandy on your orange first. it doesnt matter if you get some outside of the orange as you'll be kandying the whole tailight. make sure the paint flashes off(other words sit for a little bit to dry for the next coat). you can see when you put it on it looks wet, when its flashed off, it looks dry and dull. theres no set time but should probably be around 5min or so.
- when the orange is almost cover(probably 3 coats) put 2 or 3 coats over the whole light, even the orange. doing it like this will make the taillight look consistant and not make the orange kandied part stick out since the kandy and factory taillight color are not exactly the same color. again remember to let this shit flash off.
-when the taillight looks consistantly candied and has flashed off, untape the reverse light.
-at this point DO NOT SAND THE BASE. there is no reason too. unless your dry spraying the shit out of it base isnt gonna give enough texture to texture the clear up. only reason you should sand base is becuase you havea big ass piece of trash in it. if you have to sand the base, you have to put more paint back on the light. also give a little extra time to flash if you have to sand as you want to make sure the paint is nice and dry. at that point sand very lightly.
-clear the whole taillight.ive never used clear rattle can so i cant tell you how many coats blah blah blah. id assume maybe 3-4 medium coats with proper flash. when clear flashes off, it wont look dull like base it just wont look quite as wet when putting the next coat on. youll be able to see where your spraying is wetter looking then what youve already sprayed. if you want to cut and buff have at it.