HMG Knowledge Base
Overcoating Schedules Explained
Our Technical Data Sheets show an overcoating time that must be adhered to, to ensure sufficient curing of the coating prior to subsequent coatings are applied. This overcoating schedule presumes that:
- The paint coating has been applied to the recommended wet film thickness (WFT)
- The coating is drying in conditions that are within recommended tolerances, with particular respect to temperature, ventilation and relative humidity
- The paint used to overcoat is suitable for the application and that it is applied correctly
It is understood that it would be very difficult to maintain 100% reliability with all requirements for correct drying, so with this in mind, if there is any reason for doubt then HMG Technical Support should be contacted for advice before undertaking any work. Where maximum overcoating times are shown, it is necessary to apply subsequent coatings within this time to ensure satisfactory intercoat adhesion.
If these coatings can not be applied within maximum overcoating times then it may be necessary to mechanically abrade, or solvent wash the surface of the existing paint to ensure that a satisfactory adhesion is obtained. In this instance advice should be requested from HMG Technical Support before such work in undertaken.
Overcoating times do not give an indication of weather resistance or protection of the coating