I did some more buffing out on my test panels today (see Project Beer Fridge) and feel confident enough to make a few observations. I think the important point to remember in all this is that your are trying to accomplish an auto paint job on a budget. Atomized paint is going to go on better (less orange peel tecture) than anything rollered on. Period. If this were not the case, auto manufacturers would still be rollering on paint. The trade off for low cost is elbow grease. The bumps you're seeing in your paint job need to be sanded out if you expect to get a mirror finish. End of story. Yes, it's gonna take more coats than you expected. It's also going to take way more time than you expected. The results CAN be glass smooth in the end but you've got to be willing to put the time in to make it so. That means a significant amount of time sanding, painting, sanding, painting, sanding, painting... see what I mean. The alternative is sending the car to the body shop and opening up your wallet. Remember, this whole thread started (basically) as a discussion on how to paint your car with $50. If you're going to factor in your time in $ amounts, then it's an entirely different story.
If you are looking for a smoother surface, I would suggest sanding down again until you're satisfied with the surface, then perhaps thinning the paint a little more before giving it another coat. Be warned, you will still need to sand it again if in the end you want a "mirror" type finish. The areas that I was willing to do the same, came out very nice - glass smooth. The areas that I chose not to sand so aggressively came out with a reasonable orange peel texture. It was only my beer fridge after all, but it was also a test bed of sorts. I can definitely see where if you wanted to do an entire car, and expect to get a superior paint job in the end, you are going to need to invest quite a bit of time. To some, time is cheap, to others time is expensive. That's for you to decide.
