Points to note:

1. Control of coating environmental conditions

When the water-based epoxy anti-corrosion coating is applied in a closed and non-ventilated environment, due to the volatilization of the water in the coating, the humidity in the air will increase, resulting in the coating not drying or the coating film quality after drying is poor, and the surface has Flash rust, water stains and other undesirable phenomena. Therefore, forced ventilation measures must be adopted when painting paints in closed places.

2. Paint preparation and mixing period

For water-based epoxy coatings, especially Type I water-based epoxy coatings, the two components should be stirred evenly before mixing. After mixing, a mechanical stirrer should be used to stir for at least 5 minutes to ensure full emulsification and uniform mixing. Generally, the mixed service life of water-based epoxy anti-corrosion coatings is shorter than that of common solvent-based epoxy anti-corrosion coatings. The mixed service life of the first type of epoxy coatings is 1.5-3 hours, and the second type of epoxy coatings is 2-6 hours. , in most cases these times are sufficient for construction. However, attention should be paid to the construction, and the mixed paint should be used up within the indicated service period, and should not be used again even if there is no obvious abnormality beyond the service period.

When the single-pass film thickness exceeds a certain limit, it will bring disadvantages to the rapid volatilization of water in the paint film; at the same time, the paint film shrinks due to the volatilization of water, which may cause fine cracks in the dried paint film. Therefore, for I For type II waterborne epoxy anti-corrosion coatings, the single-pass dry film thickness should not exceed 100-120 microns; for type II water-based epoxy anti-corrosion coatings, the single-pass dry film thickness should not exceed 60-80 microns.

When the water-based epoxy anti-corrosion coating is applied to the poorly-dried solvent-based coating or the solvent-based coating is coated on the poorly-dried water-based epoxy coating, it is easy to cause poor interlayer adhesion and even peeling, which must be paid attention to.

4. Construction method

Usually waterborne epoxy anti-corrosion coatings are applied by airless spraying, roller coating or brushing, but in terms of coating quality and efficiency, airless spraying is the best choice.

The first coating on the steel substrate should not be applied by roller coating, because it is not easy to obtain a uniform coating film, and flash rust is prone to occur at the exposed bottom, missing coating, and where the coating film is too thin.

Since the water-based epoxy coating is easy to flow away from the sharp corners to form the "corner effect", in order to protect the corners from corrosion, the corners need to be smoothed, and the construction of the sharp corners, rivets and jump welds needs to be extra careful. It's best to apply it with an extra brush.