One of the differences between our ordinary steel products and galvanized steel products is that ordinary products are easy to be corroded and rusted. And galvanized products after galvanizing treatment, can effectively play a role in corrosion prevention. However, it can not guarantee that it will not rust after many years, and the galvanized rust prevention is only a short time, so it must be painted to ensure that it will not rust after more than ten years.
However, there is a big difference between galvanized sheet and galvanized steel pipe anticorrosive paint substrate and steel material, galvanized sheet is too smooth, general paint is difficult to adhere to the surface, even after drying, it is easy to fall off, unable to achieve the anti-corrosion effect. Therefore, the selection of the paint is generally the primer matching the top coat, the primer selects the two-component epoxy zinc yellow primer or epoxy zinc rich primer with strong adhesion, and the high hardness acrylic polyurethane topcoat or fluorocarbon finish is used for the top coat. The construction method of anticorrosive paint for galvanized pipe is as follows:
First of all, substrate treatment: galvanized sheet surface is very smooth, but also to use grinding treatment, so that the surface has a certain roughness, more conducive to paint adhesion.
Secondly, primer coating: the A and B components of the epoxy zinc yellow primer are mixed according to the proportion of 5:1, proper amount of epoxy diluent is added, and the mixture is fully stirred and sprayed twice. The interval between each time is more than 6 hours, and the dry time is 24 hours.
Then there is top coat coating: A and B components of acrylic polyurethane top coat are mixed in the proportion of 5:1, acrylic diluent is added, fully stirred and sprayed twice, with an interval of more than 6 hours and dry for 24 hours.
Then there is the construction acceptance: after the construction, the paint film is smooth and flat, and the color is even. At this time, there is still residual solvent in the paint which has not yet volatilized, and it takes about 7 days to dry thoroughly to achieve the desired effect.