Problem Solving Forum
October 3 - October 9, 2011
When applying a 100% solids, fast-curing polyurea coating on concrete, what is the best method for verifying that the proper thickness has been applied?
David Cerchie of Versaflex Inc. on
July 17, 2012:
The UT, stroke count and embedded metal plate meth ...read more The UT, stroke count and embedded metal plate methods are all suitable. Because of the very fast initial reactions of sprayed polyurea systems, wet-film measurements are virtually impossible. Furthermore, pure polyurea systems are normally 100% solids, so wet film thickness will equal dry film thickness. Additionally, due to the fast initial cure, surface topography is not a consideration as there will be very little flattening of the coating system. Depending on the spray gun used, there can be varying amounts of air entrainment in the sprayed systems, but generally that does not effect the UT measurements if the gauge is properly set. Some polyurea manufacturers can provide compatible hand repair polyurea if destructive testing is the only available method.
MIKE LEARNED of NEW HABIT INC on
November 22, 2011:
"MIC" a coated shim!!! ...read more "MIC" a coated shim!!!
Tom Swan of M-TEST on
October 4, 2011:
The two best non-destructive methods are 1) using ...read more The two best non-destructive methods are 1) using a UT (ultrasonic thickness) gauge preset to measure coatings over concrete. If you are a UT person, you can use a regular UT gauge, but you need the proper probe with the proper gate settings. This is good up to about 150 mil coatings. 2) The second method is to put small metal plates on the surface of the concrete prior to coating at easy-to-find locations. If you have a non-ferrous gauge, you can use aluminum tape. You can then go back to these spots and use a regular dry film thickness gauge to read the coating thickness over the plates. For destructive methods, you can use a Tooke Gauge for coatings up to about 60 mils.
massimiliano Lo Re of Studio mlr on
July 13, 2012:
The question needs to specify if dry film or ...read more The question needs to specify if dry film or wet film thickness is being verified. The topography valley of concrete substrate and its porosity must also be considered.
Kishore Kumar K R of Nukote on
October 13, 2011:
Because of air in the film, the ultrasonic gauge w ...read more Because of air in the film, the ultrasonic gauge will not give you a proper/accurate measurement. For non-destructive measurement, use the machine strokes reading and thereby the volume for a fixed or pre-measured area. Use a digital vernier to measure.
Mario Lefebvre of Polyval Coatings Inc on
October 4, 2011:
1) With an ultrasonic thi ...read more 1) With an ultrasonic thickness gauge. 2) You can also estimate the thickness applied with the square feet + number of gallons applied. 3)You can cut a piece of the membrane, but it is a destructive test, so I try to avoid it.