Moisture-Proofing Measures For Screws

Iron screws are prone to rusting in humid environments; therefore, moisture-proofing measures are necessary to prevent corrosion.

The methods for moisture-proofing screws are as follows:

(1) For vibrating machinery, use solvent-free varnish whenever possible.

(2) Ideally, select impregnating varnishes that do not contain oxidizing components, such as epoxy-urethane or unmodified epoxy-based varnishes.

(3) When using melamine-alkyd impregnating varnishes, the curing temperature and time must be carefully adjusted. A curing temperature slightly above 130°C (e.g., 135°C) and a curing time exceeding 180 minutes are recommended. Strict adherence to the process is essential - especially during hot, humid seasons - because the drying (curing) times specified in paint manufacturers' product data sheets may not be sufficient given the specific internal geometry of the motor.

(4) Use varnishes that do not contain volatile acids.

(5) Select varnishes with good hydrolysis resistance.