The cup test measures polyurethane foam properties through hand mixing. Gather supplies like cups, gloves, and a scale. Weigh the polyol and blowing agents, then mix with isocyanate at the correct temperature. Key timings to note are cream time (start of expansion), gel time (thickening), rise time (full expansion), and tack-free time (when the foam surface is no longer sticky). Finally, evaluate reaction times, density, and appearance.

Polyurethane and epoxy coatings both protect surfaces, but differ in properties. Polyurethane cures faster, offers flexibility, UV protection, and is ideal for high-traffic areas and marine use. Epoxy is more chemical-resistant, making it suitable for harsh environments. Polyurethane is more elastic, while epoxy is stiffer and more durable against chemicals.