What I'm looking for Pogue is an 'inter'coat. A clear coat you would apply between layers. For instance when I do flames on my dodgers and spoons in 3 or 4 colors, I like to protect/lock each layer. That way if something goes wrong, I don't lose the whole project, just the last application.
Also on your base. I was using Krylon flat white. Beware, you can NOT wash the water base pearls off of this base. They stain and you need to re-shoot base.
Gonna visit the hobby store and try a bottle of Createx 5601 clear base.
Edd