01Look before you touch it.Check the surface for moisture, oil, cracks and soft spots. Concrete should read under 5% moisture. Test the pH, measure the existing profile and write down what you find. Whatever gets skipped here tends to show up later as a blister.Moisture < 5%pH testProfile check1 / 6
02Prep. The part nobody photographs.Steel gets abrasive-blasted to SSPC-SP6 or SP10. Concrete gets diamond-ground or shot-blasted to CSP 3–5. It is loud, dusty and slow, and it accounts for 60 to 80 percent of whether a coating system succeeds.SSPC-SP6 / SP10CSP 3–52–4 mil anchor profile2 / 6
03Give the coating something to grab.A primer matched to the substrate goes down at 3 to 5 mils dry, usually an epoxy or a polyurethane. Depending on the job it blocks moisture, boosts adhesion, or both. It needs 30 to 60 minutes to flash off before the next coat.3–5 mil DFT30–60 min flashEpoxy or PU3 / 6
04Dial in the rig.Polyurea comes in two parts that never meet until they reach the gun. The proportioner heats both sides to 140–160°F, pumps them at 2,000–3,000 psi and holds the ratio at 1:1. Get the heat or the ratio wrong and it will not cure the way it should.140–160°F2,000–3,000 psi1 : 1 ratio4 / 6
05Spray. The fast part.The applicator builds thickness in passes of 20 to 80 mils. Each pass gels in 6 to 10 seconds and is tack-free in under 30, so you can watch it go from liquid to solid while you stand there. That quick set is why it can go on walls and overhead.20–80 mils per passGel 6–10 secTack-free < 30 sec5 / 6
06Prove it, then hand it back.Measure dry film thickness with a gauge, spark-test for pinholes (the trade calls them holidays) and pull-test adhesion where the spec asks for it. Most surfaces go back into service within about an hour.DFT gaugeHoliday test~1 hr to service6 / 6