How to Apply a Coating to a Millage Requirement
If you are doing Industrial Painting it is often important to apply a coating to a specific millage. To be able to meet a millage requirement you need to know the solid contents of your paint to be applied. The solids contents also needs to be adjusted based on any thinner that may be added. However, if you have your solid contents you can follow the following steps to ensure proper millage application.
- Whatever the solid contents of your material is will determine the millage wet needed on the surface to ensure you have met the proper millage dry. For example, if a coating is 60 percent solids and your goal is a 6 mill coating. Assuming your coating can be applied in a single coating rather than multiple coating layers for adherence, you take the needed dry mill and divide by the solid contents percent in decimal form (6/0.6) to yield the wet coat that would be needed, which would be 10 mils in this case.
- To apply 10 mils of coating you should select a spray nozzle that will allow for coating application control. This can best be determined by having a nozzle that allows for a 2 foot stream of fluid to flow with ease when pressure to the material is between 12 – 20 lbs of pressure, for this test you have no atomization air pressure to the pressure pot.
- Perform atomization test on spare cardboard to ensure proper coating breakup.
- Perform multiple passes with the gun held perpendicular to the target.
- Measure the wet millage with a millage gauge. Ensure you have obtained a wet millage equal to the number calculated in step
By knowing your solid contents of your coating and following these steps you can ensure you meet your millage specification for your coating application routinely and with great finish results.