Beijing Oil Tank Painting, Oil Tank Rust Removal, Painting Company – One-Stop Service

Products that have passed inspection, as well as semi-finished products, undergo a surface treatment known as spray painting. Spray painting provides rust protection and corrosion resistance, enhances the aesthetic appearance of the product, and serves as a means of identification. Prior to spray painting, pre-treatment work must be carried out. At this stage, a comprehensive inspection of the products to be painted is required, and any defects that can be repaired must be rectified and remedied.

1. The flowchart for the pre-treatment process is as follows: first, pre-treatment; followed by degreasing; then rinsing; followed by rust removal; then another rinse; followed by drying; then filling; and finally, dust removal.

2. The pre-treatment process specifications include operating procedures. (1) Regarding the rust removal stage: a) Rust removal involves employing the necessary physical methods to eliminate factors that adversely affect paint quality, taking into account the specific conditions of the production site and the condition of the workpiece surface. For example: Oil, dust, iron filings, rust clumps, surface rust and scale on the product surface must be manually scrubbed and removed (primarily using hand tools such as wire brushes, emery cloth or angle grinders); following treatment, compressed air must be used to remove rust dust. b) Visual inspection is used as the quality control method for rust removal. The treated workpiece must be inspected to ensure that no traces of rust or scale remain; the surface of the workpiece should simply present a uniform silver-grey metallic base.

(2) a) When removing oil and grease, pre-treatment should involve scrubbing with a degreaser (or a degreasing agent that has been sufficiently diluted). The use of organic solvents (such as petrol or white spirit) is strictly prohibited, in order to prevent the formation of a solid protective film on the workpiece surface, which would compromise the quality of the degreasing process. b) When using a degreasing agent, the workpiece should be immersed for 10 minutes at room temperature; if heavy oil contamination is present, the immersion time should be extended. The method for verifying the quality of oil removal is as follows: after rinsing with water, if a continuous film of water forms on the workpiece surface, this indicates that the oil has been thoroughly removed. (3) There are critical stages in the pre-treatment process, including: a) the handling of workpieces, When large, heavy components such as grinding discs, support discs and frames undergo pre-treatment, they must be properly hoisted, and care must be taken to prevent the workpieces from being stacked or pressed tightly against one another. b) The other stage is drying. 1) After the workpieces have been cleaned, an electrically heated blow-dryer must be used to dry the surface of the workpieces (compressed air may also be used for drying). Particularly in areas prone to solution accumulation, the workpiece should be tilted to drain off any excess solution before drying.

2) Before applying paint, the surface of the workpiece must be wiped thoroughly clean using a clean, coarse cloth or gauze, and any dust must be blown off using compressed air. Under no circumstances should spraying commence without first wiping the surface clean or blowing away any dust.

(4) Precautions prior to painting: a) Workpieces that have undergone pre-treatment must be protected by appropriate measures prior to painting to prevent rain, water or oil contamination from affecting the quality of the paint finish; b) Workpieces that have undergone pre-treatment must be spray-painted within two days; it is strictly prohibited to exceed this two-day period or to leave them for extended periods. If spraying is required after a prolonged period of storage, the pre-treatment process must be repeated. 3. Application of primer: After sandblasting and grinding, apply two coats of epoxy grey primer to the external surfaces of the equipment. Following sanding, apply a coat of acrylic metallic silver.

(1) When spraying the primer, particular attention must be paid to the edges and corners. This is because the edges and corners of the workpieces being sprayed are vulnerable areas prone to rust, and there are some hard-to-reach corners that are difficult to cover with the spray. The coating in these areas is likely to be thin, so special care must be taken.

(2) Before applying the topcoat, it is essential that the primer coat is sufficiently dry. If it is not dry enough, the primer coat may be lifted by certain topcoats; if it is over-dried, adhesion to the topcoat will be poor, and pinholes and “blistering” may occur. Furthermore, particular care must be taken to ensure that workpieces that have been primed are not re-soiled.

(3) The topcoat should be sprayed on once the primer has dried completely.

(4) When spraying the topcoat, the finish should be even, dense and glossy, and should completely cover the previous coat. Typically, two to three coats are applied, and the total thickness of the primer and topcoat should be no less than 20 micrometres.

(5) Whilst the paint film is still wet, it must be properly protected; it should be kept away from all forms of contamination and shielded from direct sunlight or freezing temperatures.

4. Where there are uneven areas on the surface to be sprayed, these can be rectified by applying filler to level the surface; this involves sanding both the filler layer and the painted surface. The role of filling in the spray painting process is somewhat contradictory; however, it is indispensable when applying paint to uneven surfaces. Therefore, the approach should vary depending on the specific object and area. Furthermore, the use of this remedial method should be avoided wherever possible.

(1) When applying filler, one must never prioritise speed or convenience; instead, the amount of filler applied in each coat should be determined by the degree of unevenness. Sheet metal components must be levelled beforehand to minimise unevenness. After applying the first coat, allow it to dry, then carry out a rough sanding to establish a reference surface as quickly as possible. Use this surface as a guide for applying the second or third coat.