Causes of uneven color after coating construction
After the paint construction, the phenomenon of uneven color, color spot, color block, color circle or cloud shape with different shades of color . The uneven color are the most common problems in the construction of architectural paint, which are caused by the coating itself, as well as the influence of the construction and the surface of the substrate and other factors.
1, floating color caused by paint
The color of paint is blended by many organic pigments and inorganic pigments, including titanium dioxide, color paste, etc., each pigment has different specific gravity. Pigments with low density float above, while those with high density accumulate below, resulting in uneven color up and down.
2, pigment paste dispersion is not good, dispersant, wetting agent dosage ratio is not appropriate, is also an important reason for color hair flower.
3, film thickness is not enough to cover the bottom or film thickness is inconsistent.
4. The basic level is not flat, in the construction, due to the coating brush is not uniform, thickness is not uniform, due to the role of light, the color is lighter when basic level is flat, the color is darker when it is convex.
5. Improper treatment of the substrate (such as excessive moisture content or ph value, alkaline substrate and other phenomena) will cause pigment paste to be color hair flower or color fading
1. Stir fully when diluted coatings, the construction of coated uniformly as much as possible. If the coating is too thin or covering power is low, it should coating again more. 2 ,putty to be scraped flat and smooth, fine polishing. lt is suggested to adjust the ph value of wall base <10 before construction, using akali resistance primer paint ,enhancing the sealing ability, prevent the overflow of alkaline substances from damaging the color. 3. Extend drying and curing period in order to reduce the alkaline of Wall Basic-level. 4. To ensure construction basement humidity, increase the water permeability resistance of outer coating thus reducing the water content of coating volatile in order to reduce the radiant with alkaline substances. 5. Choose color paste varieties with good properties of alkali resistance, such as 80 series water based pigment in LAOAN CHEMICAL