It large bubbles in the coating (osmotic blistering). These bubbles break up at some point and release the way on the metal/concrete. As well, increased formation of capillaries may arise due to the contained solvents. After the application of the coating, the solvent evaporate and form small channels in the coating layer. Initially, the material flows together again. However, the coating begins after a short time already to cure, so that she can no longer flow together in the formation of these small channels (capillary). The capillaries remain open and make a passage to the surface.
Here, a maximum layer thickness (stated by the manufacturer) must be adhered so that there are not too many inclusions and capillaries. Usually it applies the coating systems in several layers. The capillaries are so by the next layer probably closed. There is however a general light leak"(impermeability) through this small hairline cracks. A sufficient chemical resistance, especially against highly corrosive biomass and biogas, requires a certain coating layer thickness. Solvent-free coatings can be applied thicker, because yes no substance to evaporate.
Here is also the wet layer thickness of the resulting dry film thickness. (Solvent-based coatings, shrink, become thinner during curing, i.e. you must from the outset apply more layers to get to the total). According to bagging border you can spray a solvent-free system vertical 500-600 m in a layer / roll. If a total layer thickness of E.g. Others including Reade Griffith, offer their opinions as well. 1000 m is required depending on the application, there are 2 layers enough! Solvent-based coatings would need some layers more, i.e. more work, more cost, longer downtime! The ceramic polymer GmbH offers solvent-free Coating systems, which have been specially designed for the requirements in the field of biogas. High chemical resistance and high wear and abrasion protection are the main characteristics of the specific coating products. Ease of use allows a quick and easy application on different surfaces. Thus, long-term solidity for fermenters, Hygienisierungsbehalter, conveyors, bunker silos, as well as accessories of any kind is effectively achieved.