The phenomenon of paint liquid flowing downward is called sagging, which is a pathological condition that affects the appearance of the paint film. It often occurs on vertical surfaces, corners, joints of hinges, and corners where horizontal and vertical surfaces meet. Common sagging morbidity has tear-stained shape and drooping curtain shape.
Tear-like sags often appear at the corners of the edges and at the joints of the hinges. The main reason is that after brushing or spraying, the remaining paint on these inconspicuous parts was not cleaned up in time, so that the remaining paint flowed onto the paint surface and caused tear marks. The remedy for this kind of sagging is to use a brush or fingers to gently smooth the traces when the flow traces are still wet. If the sagging is dry, you can use a knife to gently flatten the tear stains, or use sandpaper to smooth the traces, and then use the paint to cover the surface.
Curtain-like sagging mainly occurs on the vertical object surface. When this happens, it looks like a sagging curtain, which is very unsightly. The main reasons are: the paint film is too thick or the paint is too thin; the brush used is small and the bristles are too soft; or the paint itself dries slowly; the proportion of the pigment in the paint is too large; or the Spray Gun moves too slowly, the spray paint is adjusted too thin, and the air pressure is too high; when dip coating, the viscosity of the paint is too high to cause sagging, and the remedy for the curtain flow control should be based on the actual situation. It depends. Usually, when such problems occur with phenolic, cool glue, and transester paints, you can immediately brush the hanging part once with a clean brush or turpentine to dissolve the hanging again, and then use a brush to forcefully push the hanging curtain away and brush it flat. If the sag is dry, use a wide scraper to level it before painting; if the alkyd paint sags, you can use alkyd thinner to wet the sag, and then use a brush to push it away and brush it flat; for spray paint sag, use the same kind Wipe off the hanging part with solvent, and then spray again; for the sagging of the dried paint film, you can smooth the sagging with south-coarse water sandpaper (but don't wear the bottom), and then repaint the paint 1~2 times .
