What color is it? I would mix the two together for consistancy also, single stage metalics are hard to color sand because if you don't put the paint on slick enough and end up with some Orange peel, then if you wet sand too much it cuts into the metalic making it look like crap. When I painted my car 10 yrs ago I used ppg paint and at the Time they didn't have my color in base clear, only single stage, so I painted car with the single stage and then cleared over it so I could color sand to a smooth as glass look. The paint I used at the time ppg recomended you wait 4 hrs before clearing, so it made an all day job to paint. If its solid color I wouldn't use clear, just put 4-5 good coats and you will have plenty of paint to color sand all the Orange peel out. hope this helps