Spraying heavy primers/coatings

What is best? Airless sprayer, paint pot, HVLP gun or schooce siphon?
Specs on one primer say it lays 3mil thick per coat. Rhino liner type coatings are also thick. Just curious what works best.

 

I use a hvlp with a 2.0 tip for heavy primers you have to move fast you could also use a 1.5 which wont piss the paint out as fast. When you are spraying high build primer the reason is to cover up the scratches and pin holes on the area you are painting dont be scared to put on lots as you will be fairring the area down till you get her true,you may even have to put another coat on and sand again all depends on how bad the surface was .I like to change the color when doing this easier to see high and low spots.
Schooce gun is great for doing rocker gaurd or non skid not the best for primer but some guys can manage them just find ,airless will work too