I have a porcelain sign that lost all of its gloss long ago and has also faded badly. I'm thinking of experimenting on one side of it with an automotive clear coat spray.

I'd like to see before and after pictures of anyone that has done this on a porcelain sign. My goal is to get a deeper, darker color and a more gloss or wet look. The sign has nearly no value as is, so I'm willing to experiment.