Amine blush can develop when using amine cured epoxy resin coatings in a multi-layer system, if the original coating cures in a low ambient temperature and/or in a high humidity environment, problems. The presence of amine blush can lead to inter-coat adhesion failures if the film is re-coated.
Elcometer 139 Amine Blush Chip Screen Kit, 20 Tests: Detects amine blush based on the presence of carbamate compounds and not on physical phenomena such as pH. Amines that have migrated to the coating surface can react with CO2 resulting in the formation of carbamates.
This can be observed as an oily film on the surface but is often invisible to the eye. The presence of amine blush will cause inter-coat adhesion failures if a further coat is applied without prior removal of amine blush. It is essential to establish if the coating exhibits the phenomenon of amine blush when determining if an amine cured epoxy coating can be over coated.
Elcometer 139 Amine Blush Kit Test Tube Comparison Stand: Six test tube holders with uniform white background for the visual comparison of the control sample vs. test samples. Amine blush is present if there
is a detectably lower intensity of yellow color observed in
the test sample as compared to the control sample.