oldermodelguy
You should also know though, not all primers are created equal. So there is something for you to determine for yourself. Primers really are quite the topic. And the topic of much controversy.
That's what it comes down to. Research is a good starting point for getting ideas, but experimentation with those ideas is going to lead you to your own, personalized solution that works best for your situation. At one point, I was even using the nasty, real Zinc Chromate primer from rattle cans that I would buy from the aviation supply place near where I work (the stuff you can't buy anymore). Also tried several of the automotive primers. Tried the Testors Model Master rattle can primers. All of them worked great, but it was really easy to screw up with a rattle can or come across an occasional rattle can that had nozzle issues that made it impossible not to screw up. At one point, after using primers for a while, I wanted to answer the question of "Are primers even necessary?" For me, I found that they were absolutely necessary for the paints I was using at the time. Without primer, I found that the paint would go on, but I could tell right away that it wasn't really sticking to the plastic. The airbrush was kind of just pushing the paint around, instead of building opacity. I read about Mr. Surfacer, which I had always thought of as a choice for filling seams, but never thought of it as a primer until I saw people doing that with it. Tried that and loved the results. Being able to airbrush it looked so much better than anything from a rattle can, just because so much of the fine detail was still sharply defined. Then it was on to experimenting with different thinners, and figuring out how much time it required to get to the optimal point of being ready for paint. I ended up using an extra Tamiya F-14A upper fuselage as my test bed, and my test for adhesion was to put a piece of Dymo label tape on it, burnish it down, and then RIP it away. When that no longer pulled primer, that ended up being the method I settled on. These days I use decanted Tamiya Surface Primer. Its essentially the same stuff as Mr. Surfacer, but my storage solution is a lot less frustrating than those little bottles with plastic lids that tended to get tiny cracks in them. I store it in a 4 ounce mason jar, and a single can of Tamiya primer goes a LONG way when thinned with MEK for airbrushing. Also made it easy to decant the entire can, by using an extra mason jar lid with a 1/4" grommet installed in it. I just epoxy a party straw to the Tamiya nozzle, let it cure overnight, and then blast that whole can through the straw into the mason jar, with the grommet keeping the gases and splashback from going everywhere.