there are some tricks you can experiment with to get those craft store paints to adhere better
you can mix a little Future in with the paints themselves, you have to thin them anyway to brush or spray them, a little bit of flow extender might help you out, too,,,,,I use Anita's, from the Hobby Lobby
LifeColor, Floquil PolyScale Railroad, and Model Master Acrylic all have a primer
the main thing is to remember that the Folk Art, Americana, and Apple Barrel paints practically insist on a rough surface to adhere to,,,,,,when I starting playing with them, they always peeled with any masking if the paint underneath was the slightest bit glossy
I know why you are using them,,,,it is hard to beat a 2 oz bottle of paint, even if you have to buy a 1oz (Floquil RR) or 3/4 oz (Lifecolor) of primer in order to use them
my "A-List" of primer and paints is LifeColor primer, a bit of Anita's in the paint (or LiquidTex Flow Aid if you can find it), and I use the same brand of primer as the paint to thin with
I hope this gives you some help with your experiments
Rex