What is the principle of epoxy zinc-rich primer re-rusting?

Epoxy zinc-rich primer It is a special coating made primarily from epoxy resin and zinc powder, supplemented with thickeners, fillers, additives, and solvents. This paint features fast natural drying, strong adhesion, and excellent corrosion resistance. It is mainly used for steel pipes, storage tanks, steel structures, containers, etc. So, what is the principle behind its re-rusting?

One, external standards

1. Epoxy zinc-rich primer Cannot be used in natural environments where air relative humidity exceeds 85%; in conditions of high environmental humidity, a layer of condensed water will form on the steel surface, which is invisible to the naked eye. In such circumstances, rust can easily occur during construction.

2. The surface roughness of steel does not match the zinc powder composition of the epoxy zinc-rich primer. On surfaces with insufficient roughness, zinc-rich primers with high zinc powder content used in construction can also rust in rainy weather due to insufficient adhesion.

3. The paint layer is too thick or too thin, much lower than the surface roughness. Epoxy zinc-rich primer is used as a topcoat for anti-corrosion and anti-rust treatment, with a coating thickness of approximately 50μm.

4. Sandblasting process cannot be performed with sea sand; sea sand contains various chloride ions, which are key elements in electrochemical reactions.

Two, inherent standards

1. Epoxy zinc-rich primer It is a construction coating widely used in the heavy-duty anti-corrosion industry, but many products have zinc content that does not meet national industry standards (the national standard for wet film zinc powder content is 70%).

2. Insufficient epoxy resin content leads to insufficient adhesion of the paint layer to steel. (Too many pigment and filler components.)

3. Epoxy zinc-rich primer the anti-rust treatment and anti-corrosion effect, where zinc powder components, epoxy resin components, and epoxy hardeners play a crucial role. This determines that the price of an epoxy zinc-rich primer with excellent anti-rust treatment and anti-corrosion effect is unlikely to be very low.