About the protection of paint

When discussing the cause of the damage of the coating, it is easy to think that the damage of the coating is caused by the corrosive effect of the environmental medium on the coating. In fact, this kind of situation rarely occurs. Especially at present, many synthetic resins have relatively excellent corrosion resistance. As long as the coating is properly selected according to the corrosion conditions, such damage will not occur.

Most of the damage to the coating is caused by defects in the coating. Because the local corrosion of the metal occurs in the defect, the local corrosion of the metal often leads to the bulging, peeling and cracking of the coating.

Question one

 Water-sensitive coatings, such as the primers of solvent-containing zinc flakes, gel or thicken.

Reason 1 | Pre-treatment parts Moisture temperature

Remedy | a) Parts pre-treated by phosphating, electroplating or passivation must be dried before applying the primer. b) If bolts, nuts or pressure parts with very low temperature are brought into the coating work area at ambient temperature, condensation may form on the parts. Wait for the parts to warm up to ambient temperature. (Tmin = dew point + 3K)

Reason 2 | Paint can is wet, dirt, temperature control

Remedy | a) Before filling, the container must be clean and dry. If the soaking container is not clean, please remove the dust, grease and moisture. b) If possible, close the container with a lid. c) When adding paint, put the entire charging tank into the container. Do not store a filling tank that is not completely emptied for later use! The filling tank will absorb moisture from the ambient air. d) Before filling the paint into the container, the paint must reach the ambient temperature to avoid the formation of condensate on the cold paint can. Do not use heaters. (Tmin = dew point + 3K)

Reason 3 | Surrounding area

Remedy | The maximum relative humidity of the place where the paint is prepared is 65% to avoid the formation of condensation on cold paint cans.

Question two

 The paint collects on the first thread on the lower edge of the head and the edge of the sheet metal part.

Cause | Too much paint that has to be cleaned up on the coating basket or slide rails can result in a failure to ensure film thickness.

Remedy | The paint in the coating basket / slide must be removed to shorten the cleaning interval.

Question three

 A lot of paint has accumulated on the thread, and the paint sags on the surface

Cause | a) The impregnation procedure is not perfect. b) The viscosity is too high. There will be assembly problems and see damage.

Remedy | a) Adjust the dip and dump program (increase the speed, increase the dip and spin time as much as possible, and add another dip and spin step as much as possible). b) Adjust or reduce the viscosity.