Most primer in a can is a 1 part meaning it does not have an activator . Anytime you can use a two part
it will have a much higher film build and be much stronger . If you were to build up a bunch of coats of 1part it will be weak and create problems . The 1part also won't self level as good as a slower drying two part . Many two part primers will also require adding reducer and need larger size nozzle sprayguns to spray them .
Here at coast airbrush we do have a two part epoxy and a two part urathane primer in a can . We also have. Free video on coastairbrushtv.com under free videos you can check out on the whole spraymax line . You can still use 1part primers and some double as adhesion promoters to plastic like the aerosol one from SEM . They can work good when not over used for high film build . I agree its best to stay within a line . It's good to know the information such as cure times on primers as well so you don't have issues with wrinkling . The new House Of Kolor Shimrin 2primer /sealers are very forgiving and offer primary colors that can be mixed to make other colors . This makes for greAter savings using less expensive color .
This also helps for better coverage of the color . We even offer pre colored color cards that can be sprayed over to test colors ! We have quite a few videos on the Shimrin 2line . More are being added all the time !