Why water sand bags and colorful cracking?

Many customers have questions such as: water sand bag not colorful coating crack? Why after the completion of wall will appear crack? In terms of crack resistance, water sand bag itself colorful coating has high crack resistance and flexibility. Under the condition of the correct construction, main body construction will not crack, coating won't craze. Water sand bag colorful coating cracking in addition to the coating itself, there are the following factors: temperature, after construction sand water bag is not completely dry, colorful coating suddenly cold climate, lead to the inner and outer drying speed is different. Surface is dry, but there is no dry, inner cracks. If putty layer is too thick, blow be bored with child several times, after spraying water pack sand color coating will appear uneven drying and cracking phenomena. If the coating is too thick, a water spray is too thick sand and colorful coating can also lead to the whole coating cracking. Better to spray a thin layer, dry spray again after the second time, normally 2 - 3 mm. If the first layer is not completely dry, spray on second time. If the first layer of coating did not completely dry, the second coating, the coating will craze.