When choosing the most adequate protective paint system for steel structures, many and diverse factors have to be taken into account. Environments, exposure conditions, chemical aggressions, durability, mechanical and thermal stresses are just some of the elements that play a part in this choice.
It is for this reason that Colgom offers to his customers a consultancy service aimed at creating tailor-made protective systems. Working in synergy with corrosion experts, painters and our process technicians, we can effectively identify and recommend the most adequate paint system to meet your needs. As far as possibile, consultancy should be carried out in planning and design stage, so that its benefits could be maximized.
Due to the UNI EN ISO 12944 high complexity, Colgom’s consultancy service can make a big difference when it comes to protect recently-built structures from corrosion. If it’s an old construction, Colgom’s consultancy service will be focused on recommending an effective maintenance programm.
Collaborating with FROSIO inspectors, Colgom offers a “second opinion” service too, addressed to customers who needs some consultancy service together with a written report certifying the effectiveness of the paint system as well as the quality of our products.
- STEP 1 - IDENTIFICATION OF THE ENVIRONMENT
Since the rate of corrosion depends on the type of structure, the conditions of air, water and soil, the 1° step of our consultancy is aimed at identifiyng the type of environment to which the structure to be protected is exposed.
Brackish waters, highly polluted industrial atmospheres with a high concentration of corrosive gases – such as sulfur dioxide – and dust particles, aggressive grounds affected by chemical substance contamination or stray currents can indeed lead to an early shut down of the structures, If not properly prepared and protected, any structure can be strongly damaged by the surrounding environment
- STEP 2 - TYPE OF STRUCTURE
Once the environment has been identified, is equally important to identify the type of the structure to be protected.
Anti-rust prevention treatments can be carried out both for new work and maintenance work.
- STEP 3 - NEW STRUCTURES
Coming in contact with the customer during the planning and design stage of the structures allow us to give suggestions about the most proper metal material to use and the shape to be given to the structure. Semplifying the shapes is determining in preventing water being trapped. We underline the importance of avoiding sharp edges, gaps and dirt accumulation, since such elements can speed up the rate of corrosion.
Moreover, in order to achieve an effective protection, weldings, galvanized bolts and insulating gasket can be used.
- STEP 4 - REPAINTINGS
Maintenance repaintings are usually performed directly on site, on operating or temporarily not-operating structures. In both cases, painting works are submitted to some limitations concerning the on site presence of workers, delicate fittings and fixtures or power lines, telephone and networking cables, flammable gases and liquids and poisonous substances that could be harmful for painters.
Before proceeding to maintenance paintings, what has to be carefully evaluated is the degree of the structure exposure to environmental conditions such as wind, dew, condensation and rusting of previously prepared surfaces. Such elements can prejudice preparatory cleaning operations, the choice of the adequate protective paint system and application method. This is the reason why a tight collaboration between process technicians, painters, the company and the corrosion expert can make a big difference.
- STEP 5 - PAINT SYSTEM
Once that the type of the structure to be protected and the environment to which it is exposed have been identified, exposure conditions, chemical aggressions and thermal and mechanical stresses have to be evaluated to achieve an adequate corrosion protective system.
Dealing with maintenance paintings, what is particularly important is to evaluate application methods and surface preparation. It is important to evaluate the condition of the previous coating and its compatibility with the new one, especially if the maintenance painting is to be applied just on those parts were corrosion happened.
To carry out this evaluation damages due to weather conditions, substrate corrosion, flacking, cracks and air bubble presence have to be carefully checked. Sometimes laboratory tests are necessary to determine the most effective painting to be applied. For example, to ensure the compatibility of the two coatings. ISO 12944 recommends doing tests to evaluate film thickness and pull-off, among others.
- STEP 6 - DURABILITY
In determining the paint system, the durability of the protection has to be taken into account too. The concept of durability is regulated by ISO 12944-1, which identifies low, medium and high range. The durability time is not a guarantee time, but a fundamental technical consideration to set up a maintenance program. Therefore, it has to be reported to the customer in the consultancy stage.
- STEP 7 - SURFACE PREPARATION
To be effective, the paint system has to be preceeded by an accurate preparation of the surface to be protected. The most effective and probably best-known method is dry sandblasting. The abrasive material is chosen depending on the type of sandblaster and on the degree of roughness to be achieved on the steel surface.
ISO 12944 defines 4 degrees of surface rustin, which are fundamental in order to define the degree of hardness and the type of abrasive material to be used for sandblasting, the distance, the pressure and the angle of throw.
- STEP 8 - MAINTENANCE
If requested, Colgom can offer periodic follow-up of the state of the art of the structure during the maintenance stage. Indeed, adopting an adequate corrosion protective system is not enough to completely avoid the risk of reductions of the service life, pollution, collapses and causing harm to people. To minimize those risks, periodic follow-ups of the structure conditions together with a preventive maintenance program are necessary. This way maintenance costs would be reduced. Colgom can walk with his customers in this path to check the painting status of the structure.