As described in the product data sheet, the second layer of ALPOL AT 307 lime finish coat should be applied on a damp, slightly coarsened surface after approx. 0.5-4 hours (depending on the absorbing capacity of the substrate, as well as air temperature and humidity) from the time when the first layer is applied, whereas smoothing should be carried out in the wet state until a completely smooth surface is obtained so that no polishing is required. It should be emphasized that finishing may last significantly longer in unfavourable temperature and humidity conditions. It is possible to apply the second layer if the existing layer has dried, although in such cases, the existing layer needs to be wetted with water to enhance finishing and prevent accelerated bonding of layers that results in undesirable formation of the so-called orange peel texture. Moreover, spraying the surface with water removes dust from the wall. Dust, if not removed, may cause the second layer to deform and to be separated from the preceding AT 307 layer. The substrate can be wetted using a standard flower sprayer or by wiping the wall with a wet cloth.