bird screen for exhaust fan

Paint on the galvanized layer, the binding force between each other and the baking temperature of the paint has a great relationship, after galvanized coating alkyd paint, adhesion is no problem. Galvanized amino paint, paint adhesion is not good. Do two bottom two surface, adhesion is ok, if the two bottom two surface to two bottom three surface, that is, more paint, more baking once, again test adhesion is very poor, poor to the paint from the galvanized layer of pieces torn off.

If the zinc coating is good, but when the light comes out in 3% nitric acid, there is a dark shadow on the coating, and the film is brown when passivation occurs, which may be caused by foreign metal impurities such as copper or lead in the galvanized liquid. When there is a problem in the process of galvanizing, check the temperature and current density first, and then measure and adjust the content of zinc and sodium hydroxide in the bath through the analysis of the bath. Whether DPE levels are low can be determined by Hull cell test.

Wire flexibility and elongation is good, can withstand the pressure of mechanical operation, in our country’s industry has played a very important role. There are many kinds of iron wire, the most common is to give black iron wire, galvanized iron wire. The corrosion resistance of the outer coating is effectively improved, but the phenomenon of crevice corrosion will be found after long-term use.