Chapter 5 Flashcards
Identify some of the defects that can be caused by incorrect application temperatures.
- Failure to cure
- Too rapid solvent evaporation
- Poor film formation
Describe relative humidity
The amount of moisture in the air compared to saturation level
What is the dew point temperature?
The temperature at which moisture will begin to form on a steel surface.
Name some of the effects wind may have on a coating project
- blowing abrasives
- causing excessive drift or overspray
- accelerating solvent evaporation
- contributing to the formation of dry spray
What are some of the common errors when using an electric hygrometer
Failure to acclimate the instrument to the environment with adequate time.
Explain the process for use of the sling psychrometer
Make sure the wick is wet and clean
Continue to sling until 3 consecutive readings are achieved
ASTM D3276, Standard guide for painting inspectors (metal substrates) states…
The minimum surface temperature for coating application is usually 5 degree
Celsius
Substrate should at least be … degree celsius above the determined dew point
3 degree Celsius
