It might be best to call your local auto paint store for advice. It would seem that the generic acrylic lacquer reducer should work, (Dupont 3608s or equivalent). I've used a lot of lacquer primer, and the mixing is not too critical, (primer is usually 1 to 1 1/4 reducer). Try it on a piece of sheet metal first, to see if it's what you like. One of the most critical elements I've found, is the spraying temperature. You want the paint to flow when you apply it. You'll be spraying a flat surface, so, runs won't be too much of a problem. I always try to paint early in the morning. Hope this helps. Good luck; Howard