Regulations on fireproof paint for steel structures need to meet the requirements of TCVN 8789:2011, that is, air humidity, do not apply when the humidity is over 85%. Ambient temperature do not apply when the temperature is below 5 degrees Celsius or above 45 degrees Celsius. The minimum steel surface temperature is 3 degrees Celsius above the dew point temperature. Excessive heat will damage the paint film. Therefore, construction conditions need to be adjusted when the temperature is above 50 degrees Celsius, the conversion of working time in the morning or evening, need to cover or bring inside the factory to paint.
Other conditions limit contamination from sandblasting from paint dust. Stop application during rain, snow, fog to avoid damage or destruction of paint film and paint loss.
+ Clean metal surfaces according to SA 2.0 standard or higher
+ Spray suitable anti-rust paint
+ Finish coating with fireproof paint
+ Finishing the color coating
+ Acceptance of works according to the standards specified in TCVN 8789: 2011
Step 1: When performing the steps to pay attention to cleaning the surface of the pre-engineered steel frame. The purpose is to help the fireproof paint stick better and determine the aesthetics that the fireproof paint line brings. Surfaces cleaned according to SA 2.0 and above are clean surfaces by thorough sandblasting. Rust residues are cleaned to reveal most of the substrate surface, then cleaned with compressed air, or a cleaning brush. Standard surface cleaning has higher anti-corrosion efficiency and rapid standardization of surface roughness. Do not paint on rusty or greasy steel. If yes, use motorcycle oil or a suitable solvent to clean
Check the cleanliness of rust paint .. on the steel surface using a magnifying glass with a magnification of 6 times on the semi-steel surface to observe. Not seeing dirt is satisfactory. Check the cleanliness of oil and grease with 2-3 drops of gasoline on the cleaned steel surface. After a time of at least 15 seconds, use paper to absorb the remaining gasoline on the face of the body. Put clean gasoline on the surface of the filter paper of the same test type. After the 2 sheets of paper have run out of gasoline, if the color of the 2 petrol stains is the same, it is clean.
For step 2: spray anti-rust primer is the layer of paint in direct contact with the painted surface. The role of primer is extremely important, helping to prevent steel from rusting and creating fireproof adhesion. The painting process needs to ensure that the material is evenly coated with a thickness of 50 µm - 80 µm on the surface and the maximum drying time is 30 minutes. After painting, it is necessary to fully test and accept the technical criteria specified in TCVN 8789:2011 on adhesion, then switch to the topcoat.
Step 3: Finish coating with fireproof paint, this is the main layer of fireproof paint and the steel surface needs to be protected. The fire resistance time of this paint layer depends on the thickness of the paint being sprayed on. After finishing, use a paint thickness gauge to check. It is recommended to use a coating nozzle during the painting process to make the surface more beautiful. Make sure the paint film has dried and reached the thickness of the test standard after completing the fireproof coating
After completing the fireproof paint to step 4: finishing the color coating, this is an additional layer of color coating to increase the aesthetics of the project. Topcoat is both the outermost layer of paint that acts as both a protective layer and a decoration
Next to Step 5: quality acceptance according to national standard TCVN 8790:2011, there are 3 steps to check the quality of fireproof paint construction. Check the drying time of the paint, the paint time between coats according to the manufacturer's regulations. Check the thickness and adhesion of antirust layers and of all paint coats. Check the paint coverage on the edges of the bolt heads, which are adjacent to many layers of steel, and other defects to guide the contractor to follow the correct technology specified by the manufacturer.
The above is the regulation on steel structure fireproof paint that we have applied to the factory projects that have been done and received many positive feedbacks from the investor, praising and helping the investor to combat risks. unexpected in the operation and production activities of the factory.
