The phenomenon of dripping, sagging and uneven paint film on the surface of the base layer can be called paint saging.
Main reasons:
1. The prepared paint is too thin, the adhesion is poor, and some paint flows under the action of gravity;
2. The painting or spray painting is too thick, and the paint film is too heavy to fall; The temperature of the construction environment is too low, and the paint film dries slowly;
3. The paint contains too many heavy pigments, and some paint sags;
4. The surface of the base layer of the object is uneven, the thickness of the paint film is uneven, the drying speed is different, and the part of the paint film that is too thick is easy to fall;
5. There are oil, water and other dirt on the surface of the base layer of the object that are incompatible with the paint, which affects the bonding and causes the paint film to sag.
1. It is necessary to select good quality paint and diluent with appropriate volatilization rate, and control its infiltration amount.
2. The surface of the object should be treated flat and smooth, and remove dirt such as surface oil and water.
3. The temperature of the construction environment should meet the standard requirements of the type of paint, such as the varnish should be 20 to 27 degrees Celsius, and the painting should be completed within 3 hours.
4. When painting, it should be carried out according to the process procedure: first vertical, horizontal, oblique, and finally vertically smooth the paint to make the coating film thickness of the paint uniform and consistent.
5. The movement speed of the spray gun and the distance from the object should be controlled uniformly, according to the prescribed process procedures, first spray vertically, ring spray, and then spray laterally to make the paint film form uniform, thickness and consistency.
The surface roughness of the paint film is specifically manifested: after the paint is filmed, the surface is uneven, and there are sand-like bumps or small bubbles.
The main reasons are:
1. There are too many pigments or particles in the paint are too coarse; The paint itself is not clean, mixed with debris, and is used without sieve;
2. The ambient temperature when mixing paint is low, and the bubbles in the paint are not completely dispersed and discharged;
3. The surface of the object is not cleaned up, there are sand particles and other debris, which are mixed into the paint film when painting;
4. The containers used (brushes, paint buckets, spray guns, etc.) are unclean, and there are residual debris brought into the paint;
5. The cleaning and protection of the construction environment is not enough, and there are dust, wind and sand and other debris stuck to the brush or fall on the paint film.
To prevent the rough surface of the paint film, we also have several precautions:
1. To choose a good quality paint, it must be carefully screened before use, evenly blended, and then used after no bubbles.
2. Pay attention to cleaning the surface of the object and keep it flat, smooth and dry.
3. It is very important to reasonably arrange the construction sequence of each type of work to ensure that the painted construction environment is free of debris and dust.
4. It must be noted that it is not allowed to reuse utensils containing different models and different performance paints, and the residues should be removed before use.
Post time: Dec-05-2022
