Lets look it this way. A common sheet of typing paper is 10 mil thick. A human hair is 2 mil thick. 300 square foot a gallon works out to just over 5 mils thick.
Now lets take a light abrasive like dust, fine sand, dirt... oh pick one, tell me just how long that 2 and a half hair thick application is going to last with a light abrasion. But I digress, you say apply 2 coats at 300 sq. ft. a gallon. (It does look good at a really low cost per sq. ft. of material). Do you think most diy's can apply it evenly at that thin of rate?
Now lets throw in some surface tension caused by a number of reasons, high humidity levels being the most common. For those that don't know what this is, it is caused by applying a viscus material too thinly and the product separates from itself, usually in an elongated "cat eye" type appearance. It pulls apart. I call them cat faces. High humidity levels can cause this even on thicker applications. The weight of the water saturated air pushes down on the epoxy and causes it to pull apart. The thinner the coating, the more it happens. Fix? Apply another coat.
Oh, another thing. For a really good surface bond, the epoxy needs to "bleed into the surface. Most people in the know shoot for a 60 grit sand paper profile on the surface. Your epoxy will never flake, or peal with that type of bond. Suddenly that 5 mil.... OK, 2 coats = 10 mils, you will lose a third of that in absorption.... which is a good thing by the way for adherence.
Scotty, I don't pretend to know a lot as I learn new stuff every day. When I started applying and then selling these types of materials I looked into it and learned as much as I could. I'm just attempting to show that a wearable surface is measured by how long it will withstand abrasion tests. Walking across a floor will abrade it. At 5 mils, you will see your path pretty quickly.
Wonder why your tire decided to steal your epoxy and take it with him? A couple of reasons. Poor prep work, (acid etching hardly ever works) or plasticizer migration. This little gem is caused mostly with acrylic sealers. There is a chemical in black rubber that "migrates" with certain chemicals in some sealers. This happens with your lesser quality epoxies. There's one that I really can not figure out how they say it is an epoxy. It's mentioned on this board often. It comes from the painting world and for the life of me I don't know how they legally can get away with calling their paint an epoxy.
The problem is there are no regulations. Even when a manufacture states it's 100% solids, sounds good but some products sold have inert solids, they do nothing for the quality, longevity, clarity, abrasion resistance, UV resistance, chemical resistance, basically they are in the mix so the manufactures can say that their product is 100%. Now there are additives that allow the product to self level better, blend easier, resist moisture better during application, (pesky bubbles) and basically make it user friendly. Some at a cost of being soft, scratch easy, are not water clear. Sorry, this is getting too long. Wasn't jumping on you Scotty, some people don't give a **** about all of this and only want a shiny floor. gene
I could be mad but it would do no good.