Painting - New paint rubs off easily

I noticed after painting my hollow-core doors and my cabinet doors with "American Tradition® Interior 100% Acrylic High-Gloss Enamel Ultra White" ($25 /gal) that the paint comes off very easily. I'm now wondering if I should have primed before I painted, but I didn't because the doors were already painted to begin with. The new white paint just doesn't seem to ''glue'' itself to the older paint, its more like a second skin. I can't imagine there being a fix for this other than to prevent me from doing this again. Any ideas on what that might be?

Thanks!

Sounds like you painted over oil base enamel. It is hard to get latex to stick to an oil base enamel. You should have either repainted with oil or sanded and primed with a solvent based primer.

You may wind up having to strip the new paint off the doors and either priming or recoating with oil base enamel.

Yeah...
It will most likely have to come off
Then sand and prime

Ack! :eek: I actually had a painting contractor do this to me once. The existing paint was about 15 years old, so the latex didn't react immediately and he actually got three doors done before he hit one that alligatored and realized it was oil paint. He ended up replacing them, as the stripping was nearly impossible (2 were louvered closet doors). If they are hollow core doors, it might be less aggravation and time cost in the long run to replace them.