I found the answer on Scroogle - just have to get the question right. This is what I thot it would be.
you have a short window.
basicly right after the solvents that are keeping the paint liquid have lifted and evaporated then you can spray the clear.
After 10 min depending on the temp, if its 80F then thats about the butter zone, colder it will take like 20-25 min sor the solvents to clear out.
Just feel the paint really wuickly and you dont want it to be tack anymore, just a little bit. put the clear on right when its still a little tacky. If you goof and miss the window and come back about 1-2 hours later then you need to wait about 2 days lightly sand it then apply the clear. what the clear dose is slightly bite into the paint when its sft to get a good hold, then it sets and like the paint the solvents that keep it liquid and halp it bite need to evaporate. and if you dont wait long enough then the solvents will push up the clear and you will get a messy spider wrinkle known as solvent pop.