Paint won't dry...

[Ashlandchris]

I recently painted a shell for a friend but have just found out that even after a week the paint still seems to be tacky and smudges. I used createx paint, dried with a hairdryer between coats, paint applied in fine coats and it seemed dry when I handed it over. Is it possible for paint to readsorb moisture? I understood that createx was heat cured so should be irreversible once dry?

Any suggestions?

I have done approx 10 shells now and haven't had this issue any other times so am at a loss?

On a slight separate note, what do people use to finish off as a final protective coat?