Painting Concrete
Painting Concrete
(OP)
We are painting concrete using an epoxy primer followed by acrylic poyurethane top coat. Total DFT is 300 microns.
We planned to use WFT readings and then as a check random Elcometer destructive DFT tests. We were then told that this sort of DFT scratch test was not to be used and we must use a PosiTector 200 ultrasonic test meter for each coat.
There are 2 things that concern me. Firstly the application of even a small amount of gel to get the reading between coats. Secondly I doubt the accuracy of the instrument. We find about 30% of the readings are not reproduceable.
Does anyone have advice on the standard practice for checking coating thicknesses on concrete surfaces.
We planned to use WFT readings and then as a check random Elcometer destructive DFT tests. We were then told that this sort of DFT scratch test was not to be used and we must use a PosiTector 200 ultrasonic test meter for each coat.
There are 2 things that concern me. Firstly the application of even a small amount of gel to get the reading between coats. Secondly I doubt the accuracy of the instrument. We find about 30% of the readings are not reproduceable.
Does anyone have advice on the standard practice for checking coating thicknesses on concrete surfaces.




