Covering problem - cracking shed

Cracking

The surface cracking of the opaque or non transparent bottom layer after the coating film dries.

① Due to external factors such as temperature changes, photothermal changes, humidity, or chemical gases causing stress changes inside the mask film.

② Use poorly weather resistant gloss coatings, such as those containing excessive drying agents.

③ Coatings with poor toughness, such as nitro coatings, are prone to cracking.

. Falling off

Due to cracking and loss of adhesion, the paint film peels off. The reason is basically the same as cracking. In addition, there may be the following reasons.

① The surface of the workpiece is excessively smooth or has moisture, oil stains, or loose oxide scales.

② When drying, the temperature is too high or the time is too long