Valve cover look bad

[Snibble]

My valve cover on my car had chipping paint chips. So I scraped off the rest of the paint, and washed it. Then I bought some engine paint and proceeded to paint. This looked good for a week.. then it started to blister. I am thinking of taking off the valve cover and taking it to some place to have a pro color it. I am afraid of removing it that I risk causing damage to the engine if I don't screw on the valve cover back on to the right spec. Anyone been in my situation before?