It really depends on your desired results. In most cases rattle can paint jobs, even with heavy clear coat, will simply chip off with any bump or scratch to the surface. I'm almost positive Rustoleum makes a clear coat. I know for sure Duplicolor does. If you have the money, most powder coat shops will paint a frame for under $100. As for the heat gun, I don't think it will do much of anything. After a week the paint should be fully cured.