Construction process steps of exterior wall coating

In our decoration industry, there are many new materials, among which exterior wall coating is the most commonly used one. Exterior wall coating is actually exterior wall coating. Belonging to water-soluble coatings and latex paints. Exterior wall coatings have many characteristics, the strongest of which is excellent waterproof performance. But also the most commonly used exterior wall coating. Exterior wall coatings also have very good decorative properties and thermal insulation properties. Then Bian Xiao will tell you something about exterior wall coatings, hoping to help you.

Construction technology of exterior wall coating

1. Building technology

(1) The base of external wall painting project should be dry, with water content ≤ 10% and PH≤ 10. Construction can be carried out under the conditions of relative temperature and humidity ≤85%. There should be no defects such as cracking, powder dropping, sanding, shelling, hollowing, peeling and lime explosion at the grass-roots level.

(2) Professional external wall putty; Scrape the putty once, level the putty once, polish the base with sandpaper, and maintain for more than 7 days until the water content and alkalinity reach the standard. Choose Bangyun paint when purchasing paint.

(3) The base of painting project must be clean, free of dust, oil pollution, slurry splashing and other pollutants. If the above attachments are found, they should be removed with shovels, wire brushes, sandpaper and cleaning agents. Then rinse with high-pressure water and dry thoroughly before painting. Construction should be carried out as soon as possible after wall treatment to avoid re-pollution.

(4) The substrate of coating engineering should not be flooded. If the substrate is prone to flooding, it should be scrubbed with 5% oxalic acid aqueous solution and then rinsed with clear water.

(5) Primer construction: When roller coating is adopted, short-haired rollers are used, and loose roller hairs are removed and soaked in solvent before use. The coating shall be a uniform and parallel wet coating. Brush the same side at once. When roller coating, the roller should avoid sticking too much paint, and use even plates to avoid sagging. The paint film must be thoroughly dried before the next layer can be applied.

(6) Topcoat construction: firstly, paint with a wet film thickness of less than 100 micron shall be painted with a common roller for the first time, and then painted with a patterned roller for the second time. When roller coating is used, the patterned roller is used first, and the loose roller hair is removed before use, soaked in clean water and a small amount of detergent, then cleaned and dried. When painting, uniform, same direction and parallel wet covering should be adopted. Brush the same side at once. When roller coating, the roller should avoid sticking too much paint, and the next layer can only be brushed after the paint film is completely dried.

2, the process of wall base treatment-full blow putty again, blow putty again, basic sand paper grinding, brush primer, brush elastic topcoat twice, local repair.

(1) Basic treatment and full putty scraping

1) After the personnel enter the site, clean and repair the dust, quicksand, bumps, shelter points and pile marks at the grass-roots level with a shovel and sandpaper. If there are micro-cracks on the wall surface that are not caused by hollowing, repair glue should be used for caulking, and at the same time, the pollution prevention and knot prevention work of related facilities should be done well.

2) Use putty, add clean water, stir evenly and adjust to the appropriate construction viscosity, and then batch scraping can be carried out. A special scraper or paint knife can be used for batch scraping until the base is smooth. The mixed putty can be used for 2 hours at 25℃, and it will be discarded after solidification, and the surface will be dried for 60min/25℃. The interval between scraping the next layer of putty shall be at least 12 hours. It should be maintained for 5-7 days before priming, and then polished with sandpaper after reaching the best strength.

3) Quality requirements: level and smooth, free of oil stains, cracks, cavities, sand holes and straight corners.

(2) The primer shall be alkali-resistant sealing primer, and no dilution is required during construction. When the construction is not easy, clean water 1%-5% can be added and mixed evenly. The construction process can be carried out by means of roller coating, spray coating and brush coating. It is required that the roller coating is uniform, without brush leakage and accumulation. The coating surface is dried for 30 minutes (25℃), and the coating interval is 24 hours (25℃). Buy lacquer and choose Bangyun lacquer.

(3) In general, it is not advisable to dilute two exterior wall coatings with water. When the construction is not easy, it can be diluted with 2%-4% water, and it should be fully stirred evenly, not at high speed. Before painting, the surface of the base should be smooth and the lines should be straight, and then the top coat should be painted. Requirements for roller brush: brush evenly, without brush leakage, accumulation and priming. The coating surface was dried for 50 minutes (25℃) and 48 hours (25℃), and the interval between coating was 24 hours ... After curing for 10 day, the film was completely formed and reached the best state.

3. Preventive measures

(1) Before using the paint, check the label and mix it carefully. Cover it tightly after use.

(2) The coating shall be stored and constructed at the temperature specified in the product manual, usually above 5℃.

(3) The paint color matching is best done by the manufacturer or distributor to ensure the color consistency of this batch of paint. If you need to mix colors on the construction site, you must use the color paste of the brand and origin provided or designated by the manufacturer, which will be prepared by special personnel according to the use requirements and proportion.

(4) Pay attention to the finished product protection of painting engineering to prevent man-made pollution caused by cross operation. If the constructed wall is polluted by dirt, it can be gently scrubbed with a clean wet rag, and repainted when the pollution is serious.

(5) Pay attention to the weather forecast before construction to avoid homework before rain and snow.

(6) Brush tools should be cleaned in time and properly kept after use.

Exterior wall coating is also called exterior wall coating. Mainly divided into water-soluble paint and latex paint. In fact, the basic performance of exterior wall latex paint is similar to that of interior wall latex paint we use. The paint film in exterior paint is hard and has stronger water resistance. So now, exterior paint is usually used for exterior walls. In addition, exterior wall coatings can also be used in places with high humidity such as bathrooms. It has very good waterproof performance, good thermal insulation performance and strong thermal insulation performance. Because the exterior wall coating has such good performance, it will be used in the new construction and renovation of large buildings such as houses, hotels, office buildings and schools.