I am about to paint a room with a water based enamel. Old coating is matt latex, I must be overly zealous when priming and painting it.
My main problem is finding a good primer, shopping around I have found and tested 2, both acrylic, one tinted (primer 1) and one not tinted (primer 2). Testing them on melamine (to simulate poor adhesion) I have found that:
Primer 1 is very thick, easy to apply, dries dead matt but is easy to wash off and strip with just water, even after 3 days.
Primer 2 is thick, calls for a 4:1 water/primer dilution (runs and drips like crazy) but when used undiluted on melamine is a tad easier to apply, covers well, dries slowly to a semi glossy sheen and cannot be removed with water, I have to use ethanol or scrape. Unlike primer 1 this one did have adhesion issues in one test (see attached photo, I have reproduced it with a paint).
My questions are:
Will the fact that Primer 1 can be removed with just water affect the adhesion and durability of it in a moist room? What about the paint's?
Will the gloss in Primer 2 affect the paint's adhesion? I know gloss surfaces do not stick as nicely, and I can't sand.
Those are all acrylic primers, Primer 2 has a decent solid content and high viscosity, would an acryl-styrene primer with an even higher solid content be better? Or is acrylic the way to go?