Future Floor Wax

Johnson Wax sells Future as a floor polish, but it's really a clear acrylic paint. Put it on a clean, reasonably smooth, non-porous surface and that surface becomes shiny. I use it on model rockets, to protect the decals and make a slick aerodynamic finish, but you could use it on all sorts of projects.

Future thins and cleans up with water. I apply it with a slightly damp foam brush, but I've heard of people using it in an airbrush. It's best applied on hot, dry days; humidity causes it to fog up.
Future cures hard enough for a new coat after a couple of hours. After a couple of days it dries hard enough to be buffed and polished with a clean, soft cloth.

Available in stores and on amazon.