akimel said:
In the absence of authentic scientific authority and evidence, all we really have is anecdotal testimony. Anecdotal testimony is not nothing, but it is one of the weakest forms of evidence. It doesn't amount to much more than opinion..
I'll often grant certain claims a bit more credibility than that...depending on who posted it and how it jibes with my previous experience. I'll differentiate between opinion and (claimed) experience.
I'd say that certain arguments can be so inductively compelling that I'll either withhold judgment, or reference them with the appropriate caveats/disclaimers, or try them for myself. But once I've tried something (to the extent that I'm confident that my experience is representative), then my first-hand observations take precedence.
Sometimes experiences just differ, and there are often a whole lotta variables that can explain that, or at least muddy the waters enough that I simply :nixweiss So sometimes we have to agree to disagree.
I understand if somebody blows me off; hey, I'm just a semi-anonymous poster on an internet forum. But when people imply, or straight-out insist, that I'm *wrong* about my first-hand experiences, that I shouldn't believe my own eyes, well then I can be sorta :argue
And regarding layering, IMO it's pretty simple:
Appearance: do you see a difference? That's that, believe your own eyes.
Bonding: when products don't bond you usually get a smeary mess, like you're wiping product #2 off of product #1. IME it's always pretty obvious that something's wrong.
Solvent-action on underlying products: can you discern a problem (or other change) of any kind? If so, reconsider what you did. If not, I wouldn't worry about it, do what you like doing.
Durability: do one coat on the entire panel. Add multiple coats to half of the panel. Add one more coat to the entire panel (to equalize the start-time for the observation period). See if there's a significant difference in [whatever criteria you value] between the two halves over a period of time.