Once a component has been cut, mounted and welded, it is not yet ready for the construction site. To ensure absolute precision, environmental resistance and long service life, the component must undergo extremely important finishing steps: leveling, surface cleaning by shot blasting and protective coating.
See more: ANALYSIS OF CUTTING, FIXING & WELDING PROCESS OF STEEL STRUCTURE ASSEMBLY
1. Straightening – Re-establishing geometric accuracy
Why do we need to adjust?
The welding process uses very high temperatures, causing residual stress and can cause the structure to warp and slightly deform. If not adjusted, assembling the components at the construction site will be very difficult and affect the load-bearing capacity of the entire system.
Implementation techniques
After welding, the structure will be passed through a specialized straightening machine. Hydraulic rollers will apply a large and controlled force to the structure, helping it return to a flat and absolutely straight state according to the design tolerance.
The Role of Quality Control (QC)
QC engineers use specialized measuring tools to re-check the flatness and straightness of the components after straightening, ensuring that all geometric parameters are within the allowable limits of the standard.
2. Surface cleaning by shot blasting – The key to anti-corrosion
This is the most important step in determining the longevity of the paint and the rust resistance of the steel structure. A well-prepared surface will help the paint adhere perfectly, creating a durable protective film.
What is shot blasting?
Shot blasting is a process of using small, round steel balls, shot at extremely high speed onto the surface of the structure.
Function
Cleaning: The strong impact force of the ball will completely remove stubborn impurities such as rust, oxide scales formed during the steel rolling process, and welding slag.
Creating roughness: The steel surface after shot blasting will have a certain roughness. This roughness is like millions of microscopic “grip feet”, helping the primer to adhere to the surface mechanically, much more firmly than a smooth surface.
Quality standards
Surface cleaning quality is often assessed according to the international standard ISO 8501-1, in which level SA 2.5 (almost completely cleaned) is a common requirement for industrial works.
The Role of Quality Control (QC)
QC will visually check the cleanliness of the surface after shot blasting, ensuring there is no rust or impurities. At the same time, they use specialized equipment to measure the surface roughness, ensuring it meets the requirements of the paint system that will be applied.
3. Coating – Protective Armor of Construction
After cleaning, the structure must be painted immediately to avoid re-oxidation of the steel surface.
- Standard paint system: A typical industrial paint system consists of many layers, each layer has its own function:
- Anti-rust primer: Usually a zinc-rich epoxy paint, which inhibits electrochemical corrosion on steel surfaces.
- Intermediate coat (if any): Increases the thickness of the paint system, creating an additional physical barrier.
- Finishing color coating: Usually Polyurethane (PU) or Epoxy based paint, which is resistant to UV rays, chemicals, impacts and creates aesthetic color for the project.
- Construction process: Painting is carried out in specialized paint booths with temperature, humidity and ventilation control systems to ensure the best paint film quality.
The Role of Quality Control (QC)
During and after painting process, QC will check:
- Wet film thickness (WFT): To control the amount of paint applied.
- Dry film thickness (DFT): Use a specialized thickness gauge to ensure that each coat of paint and the entire paint system has the correct thickness according to technical requirements. This is the decisive factor in the longevity of the paint layer.
- Paint film adhesion.
In short, the finishing stages, although occurring at the end of the process, play a decisive role in the accuracy of the assembly and the long-term life of the project. A structure that is properly aligned, shot-blasted cleanly and painted with the right technique is the commitment to quality that a professional manufacturer like Hai Long Steel Structure brings to customers.
WHY SHOULD YOU CHOOSE HAI LONG CONSTRUCTION AS A STEEL STRUCTURE PRODUCTION AND INSTALLATION UNIT?
With more than 25 years of experience in the field of manufacturing & erecting steel structures, Hai Long Construction is proud to be Leading reputable unit, providing customers with complete construction solutions, meeting all needs and requirements.
- Team experienced engineers, architects and experts, knowledgeable about the design and construction of warehouse factories according to international standards.
- Diverse construction capacity, meeting all project sizes and requirements, from simple to complex factories.
- Possessing a system of modern machinery and equipment, with a capacity of nearly 50.000 tons/year, ensuring fast, accurate and safe construction.
- Professional construction process, is strictly managed.
You are looking for one Prestigious and professional steel structure manufacturing and erection unit? Please contact Hai Long Construction for free consultation and quote:
- HAI LONG CONSTRUCTION JOINT STOCK COMPANY – MEMBER OF TAIYO GROUP
- Address: Taiyo Building, 97 Bach Dang, Hong Bang Ward, Hai Phong City, Vietnam.
- Hotline: 084 6625 888
- Email: info@hailongjsc.vn
