Really stone paint FanJian phenomenon, how should solve?

Exterior wall coating wall after construction FanJian phenomenon has been the construction personnel facing a big problem. This problem can lead to coating color, color and surface crystallization salt residues. Exterior wall really stone paint itself will not be alkaline. The traditional view, cement or lime base cannot well solidify, contains too much water, and the metope with alkaline substances. After the application of closed at the grassroots level can not seep water vapor, form the imbalance, leading to alkali and salt precipitation in the grass-roots, lead to lose adhesion coating and fall off. Fujian KeBao think coating alkali to return the original reason: surface layer, middle layer and the cured at the grass-roots level, under the action of external force and drying, solid particles can't solid coating, ooze coating on the surface of a paint film caused by defects. Prevention method and the cause analysis of acid base (1 1) 5% ~ 10% oxalic acid solution ( Prepared with 60 ℃ warm water) ； ( 2) Roller coating on the metope of oxalic acid solution to neutralize the basicity of metope completely; 2 clean base ( 1) Wash with water repeatedly from top to bottom wall; ( 2) According to the environmental temperature drying three days or longer at the grass-roots level; 3 scraping putty (cement 1) Building putty is in poly (vinyl alcohol) ( 1799). Add black cement (aqueous solution 425 #) And white packing; ( 2) Partial scraping putty layer needs to be two, each layer of putty must be polished, dry ash removal. And then to wash maintenance in time; ( 3) After curing, should according to the situation at the grass-roots level dry 10 days or longer; 4 scraping special elastic exterior wall putty 5 according to normal procedure construction cause analysis practice has proved that using the above methods are of great help to FanJian at the grass-roots level. However, due to alkali returned from several primary lacquer disease there are other reasons. ( 1) A building site found that the paint problem. The walls are painted sculpture. This project has completed more than a month, but party a found that after the rain whiskering paint film on the surface of a phenomenon that lead to large area coating color shading. Contractor think it is the result of the deficiency of maintenance time and alkaline alkali precipitation. Party a according to the engineering record of ph and the construction of the wall shows that moisture content can be normal. Once again, therefore, construction of the party a to submit and to the scene to find the reason. The authors found that the wall temperature is lower than normal temperature - — May at the grass-roots level of the moisture content is higher. Scrape off the surface of paint film, found that the middle layer and wet. Scrape off the middle tier, the dry degree of normal at the grass-roots level. Conclusion is problem in the middle. Through the understanding, admitted that the middle layer (quality Anaglyph aggregate) Not buy their own, but on their own. Ordinary aggregate usually consists of two main types of packing, one kind is quartz sand, the other is a white cement. Due to the aggregate layer is usually ( 1 ~ 3) Mm thick, so must add quartz sand to form pore, thus promotes water penetration. However, the project owner does not consider these factors. Packing is white cement and talcum powder, which makes the water in the aggregate layer will not precipitate. After coating coated to the surface, water and alkaline substances in precipitation of white cement paint can lead to disease, such as white paint and color shading. Solution is completely dry middle tier: existing and coating paint again. ( 2) A high-grade residential area on the outer walls of the old building renovation, and come true stone lacquer painting. But after a few months, a light rain washed away, left a white residue on the wall. Party b have no choice but to coating paint again. A few days later, a rain lead to the large-scale paint disease again. Party a is not satisfied. When submitting people arrived at the scene, he saw a light yellow walls with white residue. At first glance, it is caused by the whiskering. Wipe with wet cloth, the white residue is easy to erase, the film also does not have any change. After extensive to wipe, the result is the same. The authors observed that all white remains a symbol of the starting point of the wall horizontal dividing line.