Ok, you have cleared up a lot on the linking, if I am understanding what you are saying that is. Tell me if I am wrong.
A polyurethane has "many" resins, thus many different molecules to link, right? I see a urethane as let's say black and white marbles covering the floor with strings going from one to another. Then polyurethane as black, white, red and blue marbles covering the floor with strings going from every white one to every other color and every red one to every other color and so on. Am I on the right track?
Ok, if I am on the right track that is great. But now with the confusion. You say that a urethane would have a 4:1 mixing ratio with hardener and a polyurethane would have a 2:1, 3:1 or 1:1 ratio, or do you mean the ratio with iso molecules?
Because if you mean with hardener, S-W acrylic urethanes use a 3:1 ratio. And by the way, you mentioned PPG "Concept" SS in that other thread implying it was a polyurethane. But it is advertised as a acyrlic urethane, not a poly.
If you are talking about the mixing ratio with hardener, how do you know how much Isos are in said hardener by wieght or volume or what ever? Couldn't a pint of hardener from one brand or product line have a different amount of isos than another pint from another line or brand?
Ok, next question, I mentioned this in the first post. Many of these products like IMRON and S-W Genisis and PPG Delta have dedicated mixing banks. The toners and hardeners are not used with any other system. This makes sense, as far as the name it is called actually being believable. Genisis is called a "true" acrylic urethane while IMRON as I remember is a polyurethane and Delta, I don't remember, I think it is just refered to as a "urethane". Anyway, ok, they have a dedicated system.
What about something like Chromaone, Concept, or TecONE they are mixed off a mixing bank which also provides the base coats, interior colors, (with S-W a number of different urethane SS) and even acrylic enamel on some of them. All these systems use ALL the same toners for all the "qualities". All of these systems are basically, acrylic enamel systems! Yet with a different mixing clear or "drier" or something they magically become an "Acrylic urethane"?