How to Properly Choose Fire-resistant Coatings?

1. When selecting fire-resistant coatings, we should pay attention to the following points

(1) Facing fire retardant coatings cannot be used for steel structures. Facing fire retardant coatings are flame retardant coatings that protect flammable substrates such as wood structures. It cannot achieve the purpose of increasing the fire resistance limit of steel structures.
        (2) Thin-layered steel structure fireproof coatings should not be used to protect steel structures for more than 2 hours. The reason why the thin coating type fire retardant coating has a low fire resistance is determined by its own raw materials and fire prevention principles. This type of coating contains more organic ingredients. The coating only acts as a thermal barrier after forming a carbon foam film at high temperatures. The expanded bubble film has limited strength. It is easy to crack and fall off. Te carbonaceous material will gradually ash at 100 C high temperature. Therefore, steel structures with a fire resistance limit greater than 2 hours must be made with thick-coated steel structure fireproof coatings.
        (3) Fireproof coatings for indoor steel structures shall not be used directly to protect outdoor steel structures without improvement and effective waterproof measures. Open-air steel structures are exposed to the sun and the atmosphere all year round. It must be water-resistant, freeze-thaw cycle resistant, aging resistant. It can also withstand chemical corrosion by acid, alkali, salt and other outdoor steel fireproof coatings. 
        (4) In general, do not choose outdoor steel structure fireproof coatings for indoor steel structure fire protection. Outdoor steel structure fireproof coatings have strict requirements on raw materials in order to ensure their excellent performance, their prices are more expensive than indoor steel structure fireproof coatings. However, for indoor steel structures in semi-open air or some hot and humid environments, outdoor steel structure fire protection coatings should be used for protection.
        (5) Thick coating fireproof coating is basically composed of inorganic materials, the coating is stable and the aging speed is slow. As long as the coating does not fall off, the fireproof performance is guaranteed. From the perspective of durability and fire resistance, thick coating type fire retardant coating should be used.

2. Fire coating thickness detection with coating thickness meter

The fire resistance time of the fireproof coating and the fireproof coating thickness are proportional in a certain stage. The fireproof time of the same fireproof coating is different due to the different thicknesses. But beyond a certain limit coating thickness and fire resistance time will be unbalanced. Therefore, it is very important to measure the fire-resistant coating thickness with a fire-resistant coating thickness meter.

Usually we use the LS223 fire-resistant coating thickness meter to check the fire-resistant coating thickness. This coating thickness meter is equipped with two probes F3N3 and F5N3. Users can choose the coating thickness meter that suits them according to the coating thickness they measure. The instrument uses the nondestructive measurement principle of the Hall effect and eddy current effect, which will not cause damage to the coating surface. The instrument has the following characteristics:
● Simple design and operation. 
● The probe adopts ruby, which is wear-resistant and corrosion-resistant and can prolong the service life of the instrument.
● Linshang coating thickness meter can automatically identify the measurement substrate. It has three measurement modes: iron-based measurement (Fe), non-ferrous-based measurement (NFe) and automatic identification (Fe / NFe).
● The coating thickness meter uses an advanced digital probe, which is not easy to be interfered during measurement. It has high measurement accuracy.
        Linshang LS223 coating thickness meter, large range is suitable for the measurement of fire-resistant coatings, please contact Linshang official website for more details.