Clear coat

I'll simply reinforce what CNKS told you yesterday.

Judging from your post then, you have an application problem - or a material selection problem - or both. Whether or not you used a hardener has little to do with the resulting gloss. You need to review the materials you used in the paint mixture to see if they are exactly what the manufacturer of the color coat indicates on the can label. Use of "generic" products can sometimes be a problem if not specifically recommended. You also need to review your surface preparation and the application procedures and instructions provided by the manufacturer of your paint and your spray gun, particularly regarding air pressure at the gun. Here's a summary of the causes or orange peel, a situation that causes a lack of gloss in the topcoat. Forget any clear coat. It won't help anything plus it may not even be recommended by the manufacturer or be compatible with your color coat. It sounds to me that you have a basic painting problem that you need to track down and correct - by trial and error if necessary. Don't look to hardeners or clear coats to "fix" it. They won't. Do some practice painting on an old car hood or something to see if you can narrow the cause down.

Rod