Selected Answers

From FERNANDO JORGE COSTA of Versaflex on December 2, 2016:
I agree with most of the previous answer. There is ...read more I agree with most of the previous answer. There is also a hand- mix polyurea to which you can add pigments. Also, regarding the color not being the some with this kind of polyurea, you can also redo the texture because it is a very slow-set polyurea  (4 to 5 minutes). This polyurea has same hardness and elasticity as the normal "hotspray" polyurea. A primer must be used  if the substrate is concrete. For polyurea-to-polyurea adhesion, you havet o use a specially formulated tack coat.

From Mark Anater of Emery Oleochemicals on December 1, 2016:
Because it sets so fast and cures so tough, polyur ...read more Because it sets so fast and cures so tough, polyurea is difficult to repair, but not impossible. As with any coating repair, the first step is to identify the source of the problem. For instance, if there are blisters, are they between the material and the substrate, or within the material? In the first case, the cause is probably surface contamination or outgassing; and in the second, it is off-ratio spraying or dripping from the gun. Next, the defect must be removed. This is usually best done with a wire wheel on a pneumatic or electric drill. You may also use a power chisel, but be careful not to damage the substrate. Once the defect is removed, the area should be feathered by sanding,  vacuumed to remove residue, and thoroughly cleaned with acetone or denatured alcohol. The manufacturer of the polyurea should have guidelines for repair. Usually, they will recommend using the same material originally sprayed. Some may have a slow-setting kit that can be manually applied for small areas. Material less than 24 hours old can usually be repaired without additional preparation, but older material may not accept a repair with sufficient adhesion, and a primer may be recommended before the repair is done. The most difficult part of the repair is making it look inconspicuous. Because of the high film build polyurea usually requires, the area around the repair will probably have higher than desired thickness when sprayed material is used. Slow-setting, manual repair material will probably not have the same surface texture. Color and gloss on the repair may not match the rest of the coating no matter what process you use. This may not matter in an industrial application where function matters most. When appearance is critical, you may have to recoat the entire surface or remove the coating completely (or at least the surface) and redo the job.